friendship_7_plan by Skraiduolis

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 I:EUU_RY           20,i96_


        (NASA_T_I_I,]8605)            ;,1: SJLTS   _jF TH .o-
        F I;;,3T US _,Af,,ir_._cO ORL'ITAL       SPACE
                      ( N_A)      202      P
        FLIGHT            ""

RESULTS     OF THE              FIRST
FEBRUARY         20,      1962

For   sale   by   the   Sul)erintcl_dcnt   of Documents,   U.S.   (;overnrrlellt   Printing:   Office,   Wa._hingttm   25, D.C.   - Price   $1.25

                    This document         presents     the I_.sults     of the first United    States   manned
              orbital spa_   flight     conducted      on Febrmu'y       20, 1962.   The prelaamch    activities,
              spacecraft   description,    flight openttions,      flight da.ta_ ,_nd 1)o_tfli_ht           a.nalyses
              presented  form a continuation        of the inform:ttion    previously   published             for the
              two United    StNes     manned     suborbital   space flights conducted     011  _'Ia,y        5, 1961,

              and  July     '21,   1961,   respectively,     by   the     National    Aeronauti_      and     Space


                                                           PRL_EO_NG           P_IGE" BLANK        NOT       g!!._,_.le,,,
PkGE, Il            Ill
FOREWORD                   ..................................................................

1. OPERATION                         REQUIREMENTS                                     AND             PLANS              ..............................                                                           I

        By      John          D. IIodge,                Flight         Operations                     Division,                 NASA              Manned                    Sl)acecraft                Cen-
             ter;          Christopher                   C.      Kraft,            Jr.,         Chief,             Flight              Operations                       Division,               NASA
             Manned                Spacecraft                 Center          ; Charles               W.       Mathews,                    Chief,              Spacecraft                  Research
             Division,               NASA             Manned               Spacecraft                    Center;                  and         Sigurd              A.        Sjoberg,            Flight
             Operations                  Division,             NASA             Manned                Spacecraft                     Center.

2.    SPACECRAFT                          AND           SPACECRAFT                              SYSTEMS                       ..............................                                                      5

        By      Kenneth               S. Kleinknecht,                         Manager,                  Mercury                   Project,              NASA                Manned              Space-
             craft          Center;                 _Villiam           M.       Bland,                Jr.,       Deputy                  M'lnager,                     Mercury               Project,
             NASA             Manned                 Spacecraft               Center            ; and          E. M.            Fields,            Chief,              Project            Engineer-
             ing         Office,      Mercury                 Project,           NASA               Manned                   Sl)acec.raft                 Center.

3.    LIFE          SUPPORT                    SYSTEMS                   AND            BIOMEDICAL                                INSTRUMENTATION                                            .......             31

        By          Richard              S.     Johnston,              Asst.           Chief,            Life          Systems                   Division,                  NASA             Manned
              Spacecraft                  Center;              Frank            II.       Samonski,                    Jr.,        Life          Systems                 Division,               NASA
              Manned                Spacecraft                   Center;               Maxwell                   W.           Lippitt,               Life          Systems                  Division,
              NASA            Manned                 Spacecraft                Center;                and        Matthew                    I. Radnofsky,                          Life      Systems
              Division,              NASA             Manned               Spacecraft                   Center.

 4. LAUNCH-COMPLEX                                       CHECKOUT                           AND              LAUNCH-VEHICLE                                             SYSTEMS                  ......          45

        By          B. Porter             Brown,              Mercury               Launch               Coordinator,                         NASA               Manned               Spacecraft
              Center;              and         G.    Merritt           Preston,                Chief,           Preflight                  Operations                       Division,            NASA
              Manned                Spacecraft                 Center.

 5.   SPACECRAFT                              PREPARATION                              AND            CHECKOUT                            ..........................                                              53

         By         G.     Merritt              Preston,            Chief,             Preflight                 Operations                      Division,                   NASA            Manned
              Spacecraft                      Center;            Eugene                F.       Kranz,               Flight               Operation                      Division,               NASA
              Manned                Spacecraft                  Center;               and        J.      J.      Williams,                    Preflight                 Operations                     Divi-
              sion,        NASA               Manned             Spacecraft                  Center.

 6.   FLIGHT                CONTROL                     AND           FLIGHT                   PLAN            ...................................                                                                69

         By Christopher                         C. Kraft,              Jr.,      Chief,            Flight           Operations                      Division,                 NASA            Manned
               Spacecraft                     Center;            Tecwyn                   Roberts,                Flight                Operations                       Division,               NASA
              Manned                Spacecraft                  Center;               and         C. Frederick                         Matthews,                       Flight         Operations
              Division,              NASA              Manned               Spacecraft                   Center.

 7. RECOVERY                          OPERATIONS                           ................................................                                                                                       77

         By         Robert          F. Thompson,                      Flight           Operations                    Division,                 NASA               Manned                  Spacecraft
              Center;               and             Enoch        M.       Jones,             Flight              Operations                       Division,                  NASA             Manned
               Spacecraft                  Center.

 8.   AEROMEDICAL                                   PREPARATION                              AND              RESULTS                        OF         POSTFLIGHT                              MEDI-
              CAL            EXAMINATIONS                                .................................................                                                                                        83

         By         Howard                A.        Minners,             M.D.,          Life          Systems                  Division,                 NASA                Manned              Space-
               craft          Center;               William            K.       Douglas,                 M.D.,           Astronaut                      Flight              Surgeon,              NASA
               Manned               Spacecraft                 Center;              Edward                   C. Knoblo('k,                    Ph.D.,              Walter              Reed             Army
               Institute             of        Research           ; Ashton                Graybiel,                 M.1).,            USN           School             of     Aviation                 Medi-
               cine,         Pensacola,                 Fla.      ; and          Willard                R.      Itawkins,                   M.D.,              Office         of     the      Surgeon
               General,              Hq.        USAF,            Washington,                     D.C.

      9.PHYSIOLOGICAL     RESPONSES             OFTHEASTRONAUT              .....................       93

          ByC.Patrick                M.D.,
                       Laughlin, LifeSysl(,ms                  Division,    NASA     Manned    Space-
           craft Center;            P.
                         Ernest McCutcheon, I,ifeSystems M.I).,                     Division,  NASA
           Manne(1               Center;
                   S1)acecr_fft Rit_lM.Ral)p, Systems             Life             Division,   NASA
           Manned Spacecraft     Center;     David   P.Morris,                   L
                                                                   Jr.,M.D., ifeSystems         Divi-
           sion,NASA   M;lnimd      Spacecraft                :
                                                    Center;tndWilli_lm Augerson, S.               U.S.
           Army, t.Campbell,      Ky.
     10. STRONAUT    PREPARATION            ............................................               105
          ByM.Scott arl)enter,                   NASA
                                  Astronaut, Manned                 Spacecraf_    Center.
     11.PILOTPERFORMANCE           ..................................................                  113
          ByWarren               C        F
                   J.North, hief, lightCrew               Operations    l)ivisi¢)n,  NASA    3Ianned
           Spacecraft            t
                     Center;taroldI. Johnson,               FlightCrew        Operations    Division,
           NASA  Manned   Spacecraft       Center;            A.
                                                     Hehnut Kuehnel,            FlightCrew    Opera-
           tionsDivision,NASA       5Ianned      Space,.raft           _lnd
                                                             Center; John            J.VanBockel,
           FlightCrew Operations      Division,    NASA    Manned    Spacecraft     Center.

     12.   PILOT'S         FLIGHT              REPORT               ...............................................                                                                         119

              By John           H. Glenn,        Jr.,     Astronaut,                 NASA             Manne_l            Spa(_ecraft           Center.

     13.   SUMMARY               OF        RESULTS            ..................................................                                                                            137

             By      George        M.       Low,         Director             of       Space             Craft          and      Flight        Missions,             Office            of
                  Manned          Space        Flight,        NASA.

     APPENDIX              A.     MERCURY                  NETWORK                        PERFORMANCE                              SUMMARY                   FOR            MA-6_           139

                                      By     The         Manned              Space            Flight            Support          I)ivision.          NASA            Goddard
                                           Space         Flight         Center.

     APPENDIX            B.      AIR-GROUND                       COMMUNICATIONS                                         OF      THE          MA_           FLIGIIT             ....        149

     APPENDIX            C.      DESCRIPTI()N                          ()F         TIIE           MA-(;               ASTRONOMICAL.                          METEORO-

                                           LOGICAL,                    AND           TERRESTRIAL                                OBSERVATIONS                         ........               195
                                      By      John       H.   Glenn,            Jr.,       Astronaut,                   NASA       Manne(l           Spacecraft                 Cen-

     APPENDIX            D.      I'RELIMINARY                           REPORT                      ON         TIIE           RESI;LTS              ()I_'    THE            MA-6
                                           FLIGHT                 IN      THE             FIELD                    OF    SPACE             SCIENCE             ..........                   199

                                      By     John         A. O'Keefe,     Ph.D.,                                Asst.   Chief,            Ttl(_retical             Division,
                                           NASA          Goddard    Space    Flight                             Center.

                       1.     OPERATIONAL                      REQUIREMENTS                                  AND                   PLANS

By     JOHN   D. HODGE, Flight Operations Division, NASA Manned Spacecraft Center; CHRISTOPHER C. KRAFT,
        Jr., Chief, Flight Operations   Division,   NASA  Manned Spacecraft  Center; CHARLES W. MATHEWS,
        Chief, Spacecraft  Research   Division,   NASA   Manned Spacecraft  Center; and SIGURD A. SJOBERG,
        Flight Operations Division, NASA Manned Spacecraft Center

                              Summary                                        TABLE           1-L--Ground                    Stations                             for        Project
      This    paper     presents      a brief      outline    of   the
overall   operational   requirements        and plans for
the MA-6       mission.  A short description           of the                                Stations
tracking    and ground      instrumentation         network
is given     together   with general        plans     for re-
covery.     Some aspects       of flight-control        train-
                                                                                 1. Atlantic Missile
ing and simulation       are discussed        and require-
                                                                                      Range _ _
ments    for weather     forecasting       and allowable                         2. Bermuda ....
weather     conditions   are examined.           Total     per-                  3. Mid-Atlantic Ship__
sonnel   commitments       for direct     operations        are                  4. Canary Islands__
enumerated.                                                                      5. Kano, Nigeria_
                                                                                 6. Zanzibar__
                            Introduction                                         7. Indian Ocean Ship__
                                                                                 8. Muchea, Australia__
   The operational       plan    for Project     Mercury                         9. Woomera, Australia_
has been presented       in a number     of papers     pre-                     10. Canton Island ....
viously   (see refs. 1 and 2) and, therefore,          it is                    11. Hawaii ......
only the intention      of this paper     to give a very                        12. Southern California_
                                                                                13. Guaymas, Mexico
brief outline   of the preparations       for the MA-6
                                                                                14. White Sands ....
flight,. The operation        was planned     by a great                        15. Corpus Christi,
number     of different      groups   of people,      both                             Texas ...........
civilian    and Department.    of Defense,     and no                           16. Eglin (AFATC) ....
effort will be made to describe    the efforts of any
individual     group.  The entire operation      was a
                                                                         the launch    and reentry   phases,                                               and to provide
cooTdinated      team effort and was only accom-
                                                                         comnumications      and telemetry                                               data as often as
plished     by the complete     cooperation     of all
                                                                         possible throughout     the flight.                                              In addition,  six

                        Network        Stations

      In order to perform real-time  analysis   of both
the     powered   phase and orbiting    flight,  a net-                  L                                                                                                                   "             _

work of 16 stations     located    along    the three-
orbit ground    track was constructed.       The loca-
tion of these sites is shown      in figure 1-1 and
table 1-I.    The sites were chosen for a great
number   of reasons but primarily      to take advan-
tage of the existing tracking                  and data-gathering
facilities that were available                  at the start of the      _L_.      i I   t   I   J   I   [   t _   _   i   1   ,   .   J I   J   1   1   1   [    .    I   I _   .   J   I       ,   ± i    J

project.        In    addition,      it was     desirous     to make            FmITRE l-l.--Network                               stations distribution                                 for
available        continuous        real-time      tracking    during                            Project                            Mercury
of thesites             p
           at:pertinent ointsalongtheground                                                              it be necessary      to reenter      the spacecraft       as a
track wereprovidedwith ra(lio command         ca-                                                        result of some inflight       emergency.        These areas
pability in orderto t>ack suchfunctionsas                                                                are as indicated     in figure 1-9.
retrofireand clockchanges.ThesewereAt-                                                                      It was desirable      to have the capability         of re-
lanticMissileRange;Bermuda;Muchea,          Aus-                                                         covery    at the end of e'wh of the three orbits,
tralia; Hawaii; Guaymas,     Mexico;andSouth-                                                            and primary       landing      areas    located    as shown
ern California. A communications com-  and                                                               were established      for this purpose.          The forces
puting centerlocatedat the NASA Goddard                                                                  necessary    to support     the various     recovery     areas
Space  Flight Center, Greenbelt, Md., acts as the                                                        were based on the probability            of having     to end
focal        point         for these          network         sites, and by means                        the flight in a particular        phase of the mission,
of telephone    lines and microwave    links                                         provides            and the requirements         for the various      areas were
high-speed    information    to the Mercury                                           Control            normally   given        in terms   of access time to the
Center    at Cape Canaveral,     Fla.   This                                         network             spacecraft    once      the landing    had taken    place.
has proven     to be an exceptionally                                     good and ca-                   For instance,     in      the high probability    area at.
pane tool in controlling       orbiting                                   vehicles and,                  the end of three         orbits, a maximum     of 3 hours
in particular,    manned  spacecraft.                                                                    was stated as the time to reach the spacecraft.
   ( See appendix     A.)                                                                                ()n the other  hand,   the contin-geney    area lo-
                                                                                                         cated on the east c_st    of Africa   did not. have
                                      Recovery         Forces                                            predeployed    forces,  but airplane    search   capa-
    One of the biggest, considerations                  for Mer-                                         bility was provided    so that the spacecraft    could
cury operations           phmning       was to provide          for                                      be located  in at nmximum      of 18 hours.    In this
safe and quick recovery           of the astronaut.          Plans                                       _'ase, the capability      of proriding   emergerncy    aid
were made to place forces in a_large number                       of                                     by means of paramedics           was available    should it
strategic      locations      to cover      possible      aborted                                        be necessary.        A more detailed       description   of
flights during       all phases of the mission.            Figure                                        the reck)very      operation     actually   performed     in
1-'2 gives a general         picture     of the recovery        op-                                      MA-6      is presented      in paper 7.
eration.      Plans      were made for recovery             in the                                                                   Training
launch      area on the basis            of any foreseeable
catastrophe       from an off-the-pad          abort to aborts                                               In the 3 years previous                to the MA-6        flight,
occurring       at or shortly         after   lift-off.      From                                        all of the operating          elements       supplying     support
this period to the point at which the spacecraft                                                         to the operation            have gone through               various
was inserted        into orbit,      a number       of recovery                                          training    exercises       in preparation         for a particu-
areas were located            across    the entire       Atlantic                                        lar flight.      Of course,            the Mereury-Redstone
Ocean,     based     on the probabilities        of aborted                                              flights,  /_th      umnanned            and manned,        and the
flights occurring       as a result of lamM_ vehicle or                                                  Mercury-Atlas        orbital       flights previous      to MA-6
spacecraft       malfunctions.        It. was possible      to                                           were accom.plished            in preparation         for the first
choose discrete       areas on the basis of using the                                                    manned      orbital      flight       and provided        the best
spacecraft     retrorockets    to control the total range                                                and most       realistic        training.       AI_,     both     the
traveled.      In addition,       certain    areas   around                                              astron.tut      and the ground       flight-control    person-
                                                                                                         nel performed          a great      number       of simulated
the world                 were         set up      for contingencies                    should
                                                                                                         branches       and orbital    flights in preparation         for
_T   '"IlI           Tr      r L::l       2_Trrr        rr   T,TI        r_TrTr,_r               -
                                                                                                         each of these exerci_s         and were a highly trained
                                                                                                         and professional         organization        by the time the
                                                   •              X
                                                        POSTSTAG_NGad_+ >                                MA-6       flight was made.

                                                                                                                           Weather       Information

                                                                                                            As   the    whole    world      now    knows,      one   of   the
                                                                                                         most difficult    operating     problems  encountered
                                                                                                         was the weather.          Early    in the project     the
                                                                                                         NASA    solicited     the aid of the U.S. Weather
                                                                    ,         /                      ]

[             _            CONTINGENCY             LBNDING _                                         i   Bureau     in setting    up an organization         to sup-
                                                                                                         ply pertinent    weather    information.       This group
      FmURE               1-2.--Project            Mercury           r_ove_          areas.              developed     means    for obtaining     fairly    detailed
 weather              data        along             the        entire         thee-orbit                       track            ration.                  The_             camera            observations                           are         used         in

of     tile     Mercury                mission.                   This        information                        was            conjunction                        with        data         from              other             inst.rument_-
 analyzed              in many               different              ways             to I)rovide                use-            tion for establishing       launch     records.
 ful     operational                   information.                         For            instance,              de-               In some cases     where    serious     malfunctions                                                                oc-

tailed          amtlysis              of     the        weather             over           the       Atlantic                   cur,         the         photographic                       data             are         the       only         source
Ocean           for         various           periods              of the            year         was          made             for      establishing                        the      exact            sequence                  of      events.
to      provide               a basis              of     planning                   the         flight          and                  Cameras                    are      u_d          to        obtain                 trajectory               pare-
to     t)rovide              a background                         knowledge                      'ts to        what             meters                in     the       early          phase             of         launch,               for      engi-
could         be       expected               to        develop             from             day          to     day            neering                sequentials                 and           for        historical                 documen-
once          a given             weather                 l)attern             had           t)een         deter-               tation.                  They          are      located                in         the      vicinity             of     the
mined.                As       a guideline,                       weather               ground                 rules           Iaunch                 pad,         in the          general                  area          of     Cape           Cana-
were          established                     on         the        basis            of          spacecraft                    veral and                     a,long  the Florida                                  Coast           both          North
structural                  limitations                   and           recovery                 operating                     and South                      of the launch    area.

capabilities.                     These                 included              such               details           as
                                                                                                                                                                    Support                 Personnel
wind          velocity,                wave             height,            cloud             cover,             and
                                                                                                                                      As       an          indication               of      the         total             effort          involved
visibility.                  I)uring           the        days          previous                  to and          on
the       day          of      the          operation,                  the         U.S.           Weather                      in      the           Mercury                 operation,                     it     is         interesting               to

Bureau                meteorologists                           provided                   weather                 in-          note          the         number              of people                 who              participated.                       A

formation                   for       all      of       the        l)reselected                    recovery                    total           of        about            19.300            people                 were          deployed                at

areas     and          the launching    site.                             The other                  weather                    the        time             of      the        minion.                      By           far       the         largest
limitation               was the result    of                           the desi,'e                to obtain                    number                     (about            15,600)               were                 associated                   with
                                                                                                                               the       recovery                  effort.            About                 2,600          were           involved
en_ir_eering                      photographic                           coverage                     in         the
launch           area.                                                                                                         at      the       launch                complex              and          1,100             were          manning
                                                                                                                               the       tracking                   network.                     (See              table         1-II.)
                                  Optical                 Tracking
                                                                                                                                     Details                 of         spacecraft                      and               launch-vehicle
     Optical            tracking              of the            Mercury-Atl_                          launch                   prel)arations                        _u_d the             flight             plan          and         control            of
vehicle          is     part          of      the         total         launch               instrumen-                        the      flight             are      described                in subsequent                            p,_pers.

                                                            TABLE              1-II.--Direct                           6 9erations           Support                Personnel

                                                    Agency                                                                     Location                                        Function                                         Number    o[

       National             Aeronautics                 and Space             Administration__.                            Canaveral           ....                Launch           support                 ....                          300
                                                                                                                           Worldwide            .....              Network           ..........                                            50
                                                                                                                           Worldwide            ......             Flight control .......                                                  90
                                                                                                                           Worldwide            ......             Recovery ...........                                                    15

       Department                 of Defense              ......................                                           Canaveral            • .....            Launch  support                      .....                         1,900
                                                                                                                           Worldwide              "____            Network ...........                                                   400
                                                                                                                           Worldwide             ......             Recovery .........                                             15, 600
                                                                                                                           Worldwide            .....               Aeromedical     .......                                            160

       Contractor             .................................                                                            Canaveral           ......               Launch          support             ....                              380
                                                                                                                           Worldwide            ......              Network          .......                                              360

       Weapons               Research            Establishment                     ...........                             Australia         ......                 Network           ........                                             50

         • Department                   of Defense                utilizes          considerable                 contractual           support              in these          areas.


1.         CIII_ISTOPHElg C., _Tr. : Some Operational
       KRAFT,                                             Aspects   of Project Mercury.    Presented                                                                                                        at the Annual                      Meeting
     of the Society of Experimental      Test Pilots, Los Angeles, Calif., Oct. 9, 1959.
2. MATHEWS, CHARLES W. : Review          o] the Operational    Plans ]or Mercury    Orbital Mission.                                                                                                          Presented                at the 28th
         Annual             Meeting           of the Inst.              Aero.          Sci., New York, N.Y., Jan.                            25, 1960.

                       2.    SPACECRAFT                    AND         SPACECRAFT                   SYSTEMS

By KENNETH S. KLEINKNECHT,    Manager, Mercury Project, NASA Manned Spacecraft   Center; WILLIAM M.
    BLAND, Jr., Deputy Manager, Mercury Project, NASA Manned Spacecraft   Center; and E. M. FIELDS,
      Chic/,    Project     Engineering     Office,   Mercury      Project,   NASA     Manned      Spavecra]t     Center

                            Summary                                       tion contains       the crew, the life-support          systeln,
                                                                          the electrical-power          symem, and necessary,           dis-
    The Mercury       spacecraft       used by Astronaut
                                                                          plays     and     system     controls.      The    cylindrical
John It. (}lenn, Jr., in successfully              accomplish-
                                                                          section     contains     the major       components       of the
 ing the fil_, manned          orbital      flight     from     tile
                                                                          par:u'.hute    landing     system.      The topmost      section
 Uni{M     S t_Ltes performed        as it was designed.
                                                                          contains     a bieone antenna          for RF translni_sion
Performance       of all systems was at least as good
                                                                          and     reception      and the    drognm     (st_rbilizing)
as design,     and in some cases better,              as for in-
                                                                          par'tchute      which is deployed     durinff the landing
stance,    communications         and manual             at,ti_ude
control.     Deleterious     effects of minor            systems
                                                                             The large       face of the spacecraft      is protected
malfunctJons       were effectively        _voided        by" sys-
                                                                          against    re2nt _' heating    by an ablat,ion-t,ype       heat.
tem redundtmcy         aided by astronaut             corrective
                                                                          shield.     A package      which    contMns     three     posi-
action,   as in the case of the lnalfum'tionino"
                                                                          grade rocket motoI_ and thrL::_ retrograde              rocket.
control       system,    and by ample    system    de_sig_
                                                                          mot_)rs is held to the sI)acecn_ft            at the center
lnargins,      as in the cases of the lack of inverter
                                                                          of the heat shield by three straps.
cooling      and nondesign    reentry without   jettison-
                                                                             The st)acecraft,        escape system includes       an es-
ing the      retropackage.
                                                                          cape-rocket        lnotor on top of a tower which             is
                          Introduction                                    fastened      to the top of the recovery          section by
                                                                          a chunp      l'in_.     The escape-tower     as_,mbly     also
   The Mevcm V spacecraft     is de_igmed to s_stah_
                                                                          incorporates         a slnall    rocket motor    which    jet-
a man in a space environment      for a given period
of time, to protect   him from external       heating
and acceleration    during   exit and reentry,        to
provide     hinl with means        for controlling       the
attitude    of the spacecraft,       to permit     him to
perform     observations      and a limited    number     of
experiments       in sI)ace , and to then bring        him
safely back to earth with sufficient location          aids
to permit       rapid    recovery   by surface      forces.
The purpose       of this paper is to present      a brief
description       of the spacecraft       and its systems
and to provide       a limited   description    of the per-
formance       of the spacecraft         during   the first
maimed      orbital   flight from the United         States.
   The extenml        arrangement       of the spacecraft
is shown     in figure '2-1. At the ¢ime t:his photo-
graph       was taken    the spacecraft was mounted
on the      launch vehicle and was mldergohrg   final
preparatioll    for flight.   The spacecraft       is just
large   enough    to contain  the ,'Lst.romult and the
nece_ary     equipment.      The main      conical    pot-                     FIOURE 2-1.--Exterior       view of spaee<.raft     13.


             INI'[RTIONALL¥ NI[                        8LACK AND WHITE Pi'OT'3G_AP.H
                                                                     PEROXIDE               TANK

                                                                                INSTRUMENT                    PANEL

                                                                                                  MAIN AND

                      COUCH AND
                      RESTRAINTS                                          PERISCOPE

                                                  FmvaE 2-2.--Interior       view of sI_acecraft.

tisons       the tower should    the e_:al)e  motor                  be      and sequencing,       the controls             required  to initi_Lte
fired.       Ill a nornml minion    su(eh as MA-6,                  the      primary    sequences      manually,              and the nece_-_try
e_ai)e  tower is jettisoned      by firing the escape-                       flight control   (tisl/btys.
ro(.ket motor soon after laun('h        vehi(,le staging                        Within   the    pressurized    compartment,       the
wheu the aerodynamic        folve.s have decl_eased so                       major systems     near the astronaut     are batteries
that the e_ape  rocket               motor    is no longer  re-              for d-c electri(_a]     l)ower, the environmental-
quired  for a possible               abort    maneuver.    The               control  system,   an(1 major    components   of the
sl)acecraft posigrade   rocket mot()l_ provide                      for      communications      and instrumentation     systems.
_paration    from the launch     vehicle    after                  this      The astronaut    operates  control sticks with each
time for either aborted    or normal    missions.                            hand.    The right-hand     stick is used for man-
   The entire spacecraft  is nlcrmlled                 to a special          ually     controlling         the     spacecraft          attitude,     and
adapter  section on the Atlas launch                   vehicle and           the left-hand    stick can be used for initiating                       the
is restrained      by an expl(mively              actuated   clamp           escape sequence       in event of an emergency.
ring.                                                                           Between    the pressure     compartment      and                     the
    Figure      2-I_ shows     all     interior       view   of    the       heat shield    are the tanks   for the hydrogen
spacecraft.      The astronaut             is supported           by a       peroxide   which is used as fuel for the attitude
molded      couch and other             restraints    and         faces      control    system.   In addition,    the landing    bag is
the small end        of the spacecraft.        Accelerations                 fohted up and s't_)wed in this a.rea. Around           the
during    both     exit and reentry        a('t in the same                  peril)hery     of the large    pressure    bulkhead    are
direction   and      thus enable his support         couch to                vents for the which       is given off by the
be effective        without    reorientation.        The     as-             environmental   ('ontrol system.
tronaut    faces u display    of the surface  of the                            A window   is provided,    in the conic_tl section
earth   through   a periscope    and an instrument                           over     the    astronaut's         ]lead,   for    the    as_tronaut      to
panel as shown in figure '2-3.                                               use for observations      and for obtaining       visual
   The instrument      panel,   which  is shown    in                        attitude    references.    The   _stronaut    entrance
figure   24, is supported     by the l)eriscope   struc-                     and egress batch is lo('ate(] in tim ('onical section
ture.    It contains   the instrunmnts      and display                      as indicated      by the outline   to the astronaut's
lights   necessary   to monitor    spacecraft,  systems                      right.         The   astronaut         can   also    egress      through
                                             FLOOD        LIGHT

                                             WINDOW         POLE--,

                                           MAIN     PANEL    _\


                        FLOOD                                                                                                                            --HATCH    RELEASE       INITIATOR.

                                                                                                                                                                    ENTRANCE        RATCK


                                                                                                                                                                         FLOOD    LIGHT




                                                                                                                                                                         ESCAPE    HATGN


                                                                                                                                  PERISCOPE    DISPLAY

                                                                                           TOE   G U,Ikp.D5

                                                                  FIGURE     2_,-3.--Spacecraft                cabin    arrangement.

the recovery   compartment       by removing     a por-                                                       and      an insulated           double-wall                structure             for   the
tion of the instrument     panel, the forward       pres-                                                     afterl)ody.
sure bulkhead,    and the para_hute      container.                                                                                    Ablation               Shield
  The          spacecraft     at                  the  launch                  of MA-6                           The      ablation-shield                material           is a mixture              of
weighed         4,265 pounds.                      The weight                at insertion
                                                                                                              glass fibers and resin in the proper        proportions
into ox'bit was 2,987                    pounds,    and                at retrograde,
                                                                                                              such that the resin will boil off under           applied
2,970 pounds.    The                     water-landing                    weight    was
                                                                                                              heat with the glass fit_ps to provide           strength
'2,493 pounds,                  and        the recovery                    weight            was              and shield integrity.      During   the high-heating
'2,422 pounds.                                                                                                period of reentry,    the resin vaporizes      and boils
                                                                                                              off at low temperatures       into the hot boundary
                          HEAT         PROTECTION
                                                                                                              layer of air thus c_oling.
      An   artist's         conception              of the Mercury                   space-                      The shield is designed      to withstand     the heat
craft      during           the early         stages         of 't normal              reen-                  loaxts generated   by more severe reentry                                        condi-
try      is shown           in figure             2-5,      with       shading         indi-                  tions than those experienced    during    the                                    MA-6
cating       that         the    spacecraft               is surrounded                    by     a           nfission when only a few pounds        of the                                    shield
bright-orange                   envelope             of      heated           air.          The               were ,boiled away.
spacecraft            has       been   designed               to protect             the        in-                                           Afterbody
terior      from          the    effects       of reentry               aerodynamic                              The aflerbody       (cone, cylinder,  and antenna
heating.            Tiffs       heat       protection                 consists        of        an            cannister)   is protected    somewhat   from the lmt
ablation         reentry          heat        shield          for      the     forebody                       boundary     layer    of air and gaseous     ablation
                                                                                                                        [ •            •

 LEFT-HAND                      PANEL
                                                                 RIGHT-HAND                     PANEL
                                                       ,--FLIGHT       CONTROL DISPLAYS
           PRIMARY EVENTS                                                                                               I/_    ....
                                                             _...-,,,MAIN PANEL                                          "=_'+
                                                                                                                        __2 _"=              .

                            f                            .®                                                                CONTROLS
                                                                                                                          AND DISPLAYS

                                                                                                 II +:',_'-i

       _                    __EMS                        CONTRoLsVOLTAGE AND CONTROLS
                                                                 DISPLAYS                                            CONTROLS

                                                    FmUR_ 2-4.--Instrument          panels.

products     during       reentry     since most of the after-            cem of the healing          that is experienced   by the
1.My, with its inward                sloping    sides, is in the          ablation     shield;    t]mrefore   its heat protection
dead-air  region behiml             the ablation    stfiehl.   The        arrangement,       can }>e the more conventionM      dou-
aflerbodv   surface thus            receives only.       to 10 t>er-      }fie-wall   construction       with insulation  between
                                                                          the    inner    and   ouler   walls    (see     fig. 2-6).       Tim
                                                                          Mercmw       Sl>_u'ecraft afterbody    heat I)rotection,
                                                                          aS sllow]l ill figure 2-6_ consists of a double-wall
                                                                          construction     with insulation    1)etween the outer
                                                                          ,rod inner      waI]s.     In figure      2-6 lighl_weight
                                                                           fiberglas   blankets    are labeled "insulation,"        and
                                                                           eompresse(l     sm'fa<'e-clad     insulation     is labeled
                                                                          "Min-K."        On the outer        conical   surface    ,_nd
                                                                          alltelltla     section    thin   lfigh-teml>erature          alloy
                                                                           (Ren6     4t)     shingles    are used.       On the        oul_r
                                                                          cylindrica, l _ction  thicker   shingles of beD'llium
                                                                          are used in a heat-sink    arrmlgement.     The shin-
                                                                          gles are blackened     to aid the radiation    of heat
                                                                          away      from    the spacecraft,         and they   are at-
                                                                          tache(l     to the basic structure         in such a manner
                                                                          that   they    can expand      and contract       with   temper-
FI_t:t_: 2-o.--Artist's      conception     of spacecrtlft    during      ature ch,mge.s wMmut,            transferring       loads to the
                               reentry.                                   l>rimaIy-load-cartTing            spaceeraft_     structure.

                                                                  BERYLLIUM                     ment is m(xlest during       the orbital   phase of the
                       .,                                          SHINGLE/                     mission,   varying   between    200 ° F and -50 ° F,
      •051" RENE 41-,_                                                • _MI5,
                 w,                                                                    IN-K     depending
                                                                                                               upon the suit inipingement.
                                                                                                          interest  are the cabin-air
                                                                                                                                                Of par-
                                                                                                                                            and suit-air
      ,,                        _                                 INSULATION                    temperatures.     These reniain at accel)table    lev-
.22        BERYLLIUM_                                  REN¢ 41 SHINGLE _                        els during all l)hases of the mission, attesting to
                                                                                                the effectiveness   of tile environlnental    conlro]
  .016" RENE'//J"t-L;\\413__-/-I_-__                               _-_:_IN-K
                                                                                                sytem          ltnd the insulation.
                                                           S                                        Figure   2-8 shows the inaxinnliii  lell-iperalures
      WlNDOW/_,/._         _ )..._                               .01 TITANIUM                   in the ablation shield iiear the stagllation            pohlt
    ABLATION    " ".........                                                                    dliring    and after reelitry  for three orbital           re-
                                                                                                entries.     As can tie .qeen_preflight    calculations
FI(I'URE    2-6.--Arrangement               of     heat-i)rote(.tion            elenients.
                                                                                                predicted quite well the niea.sui'ed teniiieratllres,
   In order          to illustrate            the         effectivene_               of.the     As is now well known,              the MA-6        reentry      was

spacecraft     heat protezt ion, some signi fi('ant tent-                                       intentionally      [K_,gun    with the retrol)a('k         in place
                                              :) _,                                             ili tile center of the shield.         Thus_ it is parti('u-
peratures     are presenled     in figure 2-1.         Front an
overall    standpoint,     the most _vere            beating     is                             l'u'ly interesting       to liole that the luaxilnuul          teui-
encountered       during   reentry.       During      this tinie,                                perllture    iYleaslire(t near the stitgnalion           pohit in
                                                                                                 the MA-6 shield was liot nnich lower than those
the air cap surrounding             the front       end of the
spacecraft      has i_maxinnml       teniperature       of i_bout                               niea.sured during lhe MA4   all(| MA-5 rex_ntries.
                                                                                                This and other available evidence indicates that
9,500 ° F, which is nearly           the same as the tem-
i)erature    of the surface of the sun.             As a result,                                lhe relrol)ack                     disintegrated                froni     reentry         heal-
the surface       of the heat shield i'ei_ches It maxi-                                         ing during the early part of the reentry so thai
nmm temperature            of about      3,000 ° F and the                                       its l)resence ula(le little difference lit tim total
Sl)lu?ex_raft afterbody       shingles     attain maximum                                       heat     input          to the shield.
temperatures       in the order        of 1,000 ° F on the
                                                                                                                      SPACECRAFT                               SYSTEMS
thin shingles      and about 600 ° F on the thicker
                                                                                                                           Rocket                Motor         Systems
    During    the exit flight, when the small end of
the spacecr_.ft     points     in the direction    of flight,                                       The          rocket                 niotor      asseinl)lies           used          hi     the
the aftert)ody       shingles      are also subjected       to                                  Mercury   sl)acecraft    are its shown     in figure 2-9
aerodynaniic      heating,    attaining     maximum    tem-                                     and are listed in the following       table along with
l)eratures   as high its .tbout 1,300 ° F. With the                                             their nominal     performance     characteristics.
local temperatures         dependent      upon   local flow
conditions     and tlie thermal         mass of the space-
craft surfsce.                                                                                                                                                                     Approx-
                                                                                                                                                    Number         Nominal           imate
   The temperature     variation                                 of the outer shin-                          Rocket             motor                  of           thrust         burning
                                                                                                                                                    motors         each,   lb         time
gles around    the astronaut's                                  pressure  compart-
                                                                                                                                                                                   each,   so,

                EXIT, 1,300
                ORBIT, 200 TO-25                                                                                                                                                          1
                                                     f      EXIT, 700                                   Escape        .......                              1        52, 000
                REENTRY, 850    ,,,,                ,,'     ORBIT, 150 TO -50
                                                                                                        Tower jettison ......                              l             8OO              1.5
                                                   /        REENTRY, 1,000
                                                                                                        Posigrade ......                                   3             4O0              1
                                                   "               EXIT, t50                                                                                                             10
                                                                                                        Retrograde .....                                   3          1,000
                  3,000.                         ,,"      ,,"      ORBIT, I00 TO 0
SHOCK WAVE:                                                        REENTRY, 600
 9,500 AT START
 OF REENTRY i                                                       CABIN AIR:                         All       of       these            rocket        motors           eniploy         solid-
 7,500 AT MAX                                                          EXIT, 85                  l)ropellant  fuel.
                                                                       ORBIT, 105 TO 90
                                          SUIT AIR:                    RECOVERY, 105                 The escape rocket                              is mounted             at    the     top     of
                                           EXIT, 65                                              the     escape            tower           and      incorporates            three        canted
                                           ORBIT, 65 TO 75
                                           RECOVERY, 85                                          exit        nozzles              to direct,         the       exhaust          g.lses        ,tway
                                                                                                 front        the side             (if the sI)acecraft.
 FIOVRE      2-7.--Represent'ttive                     temperatures            ill   degree._
                                     Fahrenheit.                                                       The       tower             jettison          rocket        also     has        it three-

                       \             o   MA-4                                                                                  I             TOWER JETTISON
                                     [3 MA -5
   ,see \                            + MA-6

  I000                     _,
      500                                          _o_.._._"                       ....        u .....

          0                     20                 40                         60              80

                       DEPTH         FROM OUTER                         SURFACE,      PERCENT

 lemua_          2-8.--Maximum                          ablation-shield                   temperatures.

nozzle assembly     and is attached   to the bottom                                                                                      FrOURE     2-9.--Spacecraft          rocket   motors.
of the escape rocket-motor    case.
   The three    posigrade   and three     retrograde                                                                    rocket     motors are ripple-fired        (5-second      delays
rocket  motors are mounted      in a package     which                                                                  between       motor  ignitions)      and provide        the ve-
is held to the sl)acecraft      at the ('enter of the                                                                   lo(,ity (lecremehl      necessary      to initiate    reentry.
heat    shield by three    straps.     The l)osigrade                                                                       All rocket motors have dual ignition               systems
rockets    are salvo-fired   to separate    the space-                                                                  from      sel)arate   electrical     power      sources.      In
craft from the launch      vehicle.    The retrograde                                                                   addition,      each ignition     system has dual squibs


  I                                        •            _,T(L_,TE
                                               I                         I bMT_. cc,,.,._

                                                                                                   __.'.._-_J                        .........
                                                                                          i                                                               I


              ......                           t                          I

                                                        /                                                                                                 t
                                                    /                                                                                                     I

                                                                                                   ...................... :__


                                                   \\           L .............                     _                                                     I
                                                        \                                            I                                                    I

   ....                                                             •

                                                                              ........                                                              2
                                                                                                                                                  :;L_, _,

                                                                         F_U&E        2--10.--Retrorocket               fire       schemv£ic       diagram.

to insureignition. A typical     example of rocket-                                   rI'he mode of (_)ntrol can be easily _le('le(l  by
motor system firing circuitry      is shown ill figure                             the astronaut     by positioning    of the 1)roper
2-10.                                                                              switches   and valves mounted    on the instrunmnt
   In the MA-6   missmn,     all rocket     motor sys-                             panel.    It shouhl also be noted tlmt                              certain   of
tems appear   to lmve <)perated       I)roperly.   The                             the_   control   modes can be selected                             to operate
escape towel" was jettisoned      'ts planned    at the                            sinmltaneously,         such   as ASCS     and    MI ), or
 i)rol)er  lime.    The   firing   of the posigrade                                FBW        and MP, in order to l)rovided       double   au-
rockets   provided    the expected   velocity clmnge,                              thority      or so that    even with certain     malfimc-
as did the retrorocket    motors.                                                  lions in e_tch m(xle, (.omplete         control    can be
                                                                                   maintained.         Also of interest    is the type       of
                          Control           System
                                                                                   electrical     I)ower requirement    for each of the_
   The control       system    of tim Mercury    space-                            control     arrangements.          Most significant      is the
craft    provides     the capal)ility  of performing                               lack of any elect rical l)ower l_quirement             for tlle
sever'tl   functions     vital to a successful  orbital                            manual      prol)ortional      control mode.
mission ; they are attaining     a preci_    attitude    for                          The thruster        iml)ulse    is directed    by the four
retrofire  and hohling    the attitude    closely during                           basic     control      modes     through       18 individual
the stepped    thrusting  period of the retrorockets.                              system,       as shown        in figure       2-11.   Figures
Without     such control,   an orbital    mission     would                        thrusters--12        on system A and 6 on the manual
very l)robably           suffer mission   failure.                 Because         2-12(a)    and 2-12(b)    show               the A and              B systems
of this critical           function,  lhe Mercury                   control        RCS     schematic    diagrams.                  Figures               2-12(a)
system       has    been designed               so that    it can per-             and '2-12(b)    (lo not show completely        the meth-
form        its     function    in             event    of    multiple             ods of electrically    controlling    the thrustel.'s;  in
malfunctions.                                                                      figure 2-1O_(a)     there    is 't switch   missing    be-
   Table 2-I         indicates        the     four    control     arrange-         tween the hand controller        and the ASCS control
ments     that     are availal)le           in the present        MercuD"          box which 1)emnits selection       of either   FBW     or
spacecraft.    Basically,   there are two completely                               ASCS.     Similarly,    in figure 2-12(I))     the con-
independent      fuel     supply,    plumbing,     and                             nection of the hand controller       through   a switch
|hruster systems.      Each uses 90-percent    hydro-                              and the ASCS control         box to the thruster   sole-
gen peroxide           to provide selected impulse   as de-                        noids for RSCS       control    is missing.    Metere(1
sired.  There           are two means of controlling    the                        quantities    of hydrogen       peroxide   are decompo_d
outputs    of each of the_      systems;  th'tt is, on                             in silver-plated        cataly_      beds in each of the
system   A the astronaut      has a choice of using                                thruster    chamt)e_       to provide     the desired    im-
either  the automatic    stabilization   and control                               pulse.     Twelve     of the thrusters         u_d   on the
system (ASCS)  or fly-by-wire     (FBW)                                sys-   Mercury      spacecraft      are sized to provide      ade-
tem.   The ASCS is automatic     to the extent                              that   quate control     during     the retromaneuver.
it_ can     provide            the   necessarT         attitude         control        The_ thruster       ratings    are as follows:
throughout   a complete  mission   without   any ac-
tion on the part of the astronaut;   this is the sys-
                                                                                                        Axis                System          A,       System          B,
tem that was used on the unmanned           Mercury                                                                              lb                        lb

missions.    The    FBW       system      is operated   by
movement     of the astronaut      control stick to oper-
                                                                                        Pitch      ...........                    24                    4 to    24
ate the solenoid   control valves electrically.                                         Yaw     ..............                    24                    4 to    24

   On system      B the asti'on_ut          has the choice                              Roll    ...........                           6                 lto6

of using either the manual           proportional        system
(MP)     or the rate stabilization           control     system
                                                                                      The       remaining          six thrusters             are     in system            A
(RSCS),      both of which are operated                through
the ,astronaut's     control    stick.     In the MP sys-                          to provide   fine art itude control  as desired under
                                                                                   orbital condit ions with minimum        fuel eonsuml)-
 tem, linkages    transmit      the control       stick move-
                                                                                   tion.    Each of these, six thrusters     has a thrust
ment to proportional         control valves which regal-
late the flow of fuel to the thrustei.'s.                    The                    rating of 1 pound.
 RSCS     uses a combination            of stick positions                              On the MA-6 mission                 the control              system,         with

 and      the    computing            components            of    the      auto-    essential           mode     (.banges    by       the        astronaut,           pro-

 matie     system       to provide           rate    control.                       vided       adequate         control     of spacecraft                attitudes

      2-I.--Spacecrafl ('ontrol
T._BI,z                                                                                    Sy*'tem    Re-                 attained       and       maint'tined         accurate    control     for
  dundancy                     and Electrical                         Power             Requirement,_                     retrofire     by by using both automatic           and man-
                                                                                                                          ual     attitude-control           modes,   and   a('curately
         (!ontrol                    Corresponding        fuel                              Electrical                    achieved       entry     altitude.     During   entry,    after
          system                          system    (fuel                                       pOW(W

           modes                     supply,     plmnb, ing,                                  required                    maximuln   (lynan_ic    l)ressure_                   the   astronaut
                                        :rod thrustprs)                                                                   while on manual    proportional                     and fly-by-wire
                                                                                                                          control  sucee._sfully controlled    the lateral   oscil-
       ASCS             _             i                  ......                           d-c     and      a-c            lations until the B-system       fuel supl)ly was de-
       FBW_         _ _.              i   ...........
                                                                                                   d-e                    pleted.   At this time the oscillations        began to

       MP_-                -                                                                     None
                                      R    ..........
                                                                                                                          build up; however,     switching     to an automatic
       RSCS     .....                                                                     d-e     and      a-c
                                      n   ............
                                                                                                                          m(xte did reduce oscillat ions to within desirable
                                                                                                                          limits until         the    A-system         fuel   supply      was also
ASOS--Aatomatie                           stabilization                     and     control            sTstem             depleted.
MP--Manual                     protm_iortal                       sys-|Oontrolled                by      pilot    a('-          Communications                   and    Instrumentation
  tern                                                                  _     tuation             of       (-ontr_)l
RSO_q---l_te                   stabilization                      con- /      stick
  t rol system                                                         )                                                     The spacecraft      e, mununications       and instru-
during         all phases of the mission    despite  recur-                                                               mentation     systems     consisted     of voice, radar,
rences        of small thruster   malfunct ions which dis-                                                                command,     recovery,    and telemetry      links. Each
abled         the minimum       fuel consumption      mode                                                                system    had     main   and backup        (or parallel)
about the yaw axis early    in the nfission.    As                                                                        equipment      for redundancy,        with _leetion       of
discussed in paper 11, the astronaut   very satis-                                                                        the desired    system    _enerally   at discretion     of
factorily  completed    his planned                                                      maneuvers      in                the astronaut    through    switches  nmunted     on the
space, orientated    the spacecraft                                                      as he desired                    instrument    panel.     Table 2-II    is a list of the
to make terrestrial     and celestial                                                     observations_                   systems,   and figure "2-13 shows the physical        1o-

                                                                       FIOURE           2-11.--Arrangement               of   reaction   control      system.



                           (a)   System       A.

FIQURE   2-12.--Reaction     control      system   m, hematic   diagrams.

          (b)   System   B.

                                                                                                                         RECEIVER      {A)   a   (B)

                 MAIN        HF

                HF        O_PLE    XER










                                                  FIGURE               2-13.--I,o_ations                       of    major          components         of   communications        system.

TABLE                  2-]I.--Spacecrafl                                       Communications                            and                 cation    of the     communications            equipment       in the
                             Instrumentation                                    Systems                                                      spacecnLft.    The    performance    of               the wlrious
                                                                                                                                             communicatio_l     links was generally                  very good
                                            Voice           communication
                                                                                                                                             during     tim MA-6 minion               as shown in figure 2-
          UHF             transceiver                  ............                       2 watts                                            14.     The time for which useful sigqmls were ob-
          UHF             transceiver                  .....                              0.5     watt                                       tained for each link ttre compared                   with the time
          HF     transceiver                      ..........                              5 watts                                            that the spacecraft           was within ]ine-of-sight              for
                                                                                                                                             e_ch pass          over    two se]ected           range     stations.
                                                                                                                                             This same comparison                 was made for each i)a_s
          C-band              beacon              ...........                             400-watt                                           over each range station,               averaged      for the entire
                                                                                             transponder                                     mission,      a_ld presented           in percent      form in the
          S-band             beacon           ............                                1,000-watt                                         right'-hand       column of figure 2-14.
                                                                                      J         transponder                                      Since      the IIF       voice system           was not used
                                                            Commands                                                                         enough      in the MA-6 flight to allow a meaning-
                                                                                                                                             ful assessment          of HF coverage,            the HF cover-
          2 command                       receivers              .......                  10 channels                                         age shown          in figure        2-14 is for the MA-5
                                                                                                                                             orbita]     flight     which      utilized     a tape recording
                                                            Telemetry                                                                        for spacecraft,          voice broadcasts            on both       HF
                                                                                                                                             and      UHF        systems.        A simplified          schematic
          2 FM             transmitters                     .......                       2 watts             each
                                                                                                                                             diagram         showing      the various         communications
                                                                                                                                             systems       and their        respective       antenna      systems
                                                                                                                                              is shown        in figure 2-15.
          HF         I)/F         beacon              SEASAVE__                             1          watt                                      Vo;ce sy,_tem.--The               voice system_         used for
          UHF              D/F           beacon             SARAH              ....         7.5        watts
                                                                                                                                             two-way      voice   conversations         between    the
          UHF    D/F                        beacon                SUPER-                  91           watts
            SARAH.                                                                                                                           ground    and spacecraft,     was made up of high-
          HF     transceiver                      ...........                               ]          watt                                  frequency      (IIF)      and   ultra-high-frequency
                                                                                                                                              (UIIF)    systems.     From     previous     orbital ex-

                                                NETWORK     SUMMARY                                              SUMMARY
                        CALIFORNIA                                MUCHEA      (AUSTRALIA)                  USEFUL TIME IN
                       ORBIT       NUMBER                           ORBIT     NUMBER                         % OF LINE-
                   I                2                3             I                2                3     OF-SIGHT TIME


                         V/,_Y/,'_                                                                                  113


                                                                         NOT APPLICABLE                             78

  RECEI-                 PERFORMANCE              HAS BEEN SATISFACTORY

 METRY                                                                                                              97

   ERY                       PERFORMANCE              HAS BEEN   SATISFACTORY

                                            1              11                1
* MA-5      DATA

     KEY:    _            USEFUL TIME,  (x) MINUTES
                          STATION LINE OF SIGHT TIME,              (x)    MINUTES

                          FIGURE     2-14.--l'erformance    of spacecraft    (,()mnmni(-{ltious   links.

                                                                             REQ        I   COMI
                         fl                          LTELEMETRY/I TELEN
                                                     I HI-FREQ I    LO-I     ErRY   I

                                                                                                   _               I         ]
                                                                                                           I COMMAND I COMMAND                   UHFI
                                                                                                                                     VO'__E I MAIN


                                                                                                                                            ANTENN, A SW_TCH


                                                             ANTENNA      MULTIPLEXER                                                 ,N_


                      C AND    S   BAND   ANTENNAS         ALJX UHF
                                                                       H.F, RECOVERY
                                                                                            UHF DE_ENT        BICONE
                                                            R_E          ANTENNA            AND RECOVERY    ANTENNA
                                                           /_'WTENNA                         ANTENNA          ORBIT

                      _IGURE       2-15.--Communications                    and antenna systems s(.hematic               (]iagram.

                                                                                                                                                                     MAiN      BICONE
                                                                                                                 LOW            PWR




                                                                                                                                                                  : L---*
                                                                                                                                                                      _'                 N


                                                                                                                                                                              > N
                                                                                          •       I
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                                                                           I              R       IRECEIVER                    &   DEGOOER

                                                                     |                    :I                     I
                                                    I   C,%RM' _         D     FUNCTION               I

                                                    I   INITIATE         RETRO     SEQ                I

                                                    I   RESET      CLOCK                              I
                                                   Im                                         mill

          TELEMETRY     KEYING

                                                                                              T             TELEMETRY                            J_.

                                                                                                  i              HI        FNEQ

     t,                                    I
     |      iNSTRUMENTATION                    |

     IL        SYSTEM     (i_F._.      __ j I

                                                                                                             LO   FREQ                       _   J

                                                                         LOW     FREQUENCY                            _                     OFF
                                                                                                             j                 HI-PWR    TLM            ]

                                    FIGURE         2-16.--Voice                     systems                        schematic                           diagram.

perience  and ground      tests, it was known      that                                                               str]i]nelit              calibre|                iOli            :iiid        lo      ()l)iain             ;l(I,Iiii(mal
the IIF system     had somewhat      poorer  voice fi-                                                                data          on     tile         coniniand-systcni                                     iiltligill            perforn]-

delity but longer    range than the UHF       system.                                                                 ill]Ce.              The            onboard                         conilllalld                      systelii             con-

The UIIF    system, b_callSe of its slightly    better                                                                sisied          of two                i(leniical                     receive]'s                   and (lecodel_,
voice quality,    was considered   to be tile primary                                                                 eacli         callable              of         l)erforniing                        ai]y          reqllire(|            flint-

system.      From    p_vious     experience,       it wits                                                            lions.    The (hlia are being ._lii(lied Io evahulle
known   tlmt the range of the UItF           system   was                                                              lhe coni]nan(l-systein         l)erfo]'l]lai]ce,      w]ii('li     has
approximately    equal to the line-of-sight                                                           range           been sittisfa(.lo]'y      ill previous        orb|i'll   ]]lissions.
and was entirely     adequate   for a normal                                                            mis-              Te/(,m(4ry      xy._'/<'m.--Tlie        telemetry         syste]n

sion.   Tlle main voice traffic was therefore                                                           con-           consisted of two nearly           identical       FM-FM          tele-
ducted         on the UIIF                    systenl,             with a small                     anlount           lnelry sllbsystenis, each car]'ying   essentially the
of traffic conducted         on the HF system to verify                                                               same data for redllndan('y    and each ||sing c,oln-
system      operation.       It might   be noted that the                                                             niulaled   an(l (.(nitinuous chan]leis.   Tlie ael'o-
ITIIF systenl consisted          of a main and a backup                                                               medical                data               a]ld              _)nie              systeni-l)erforniance

translnitter-t_ceiver.            Thus,    three   selmrate                                                           infor]na,tion                       fron]                 tile           tele]lleti'y                system               were

voice systems          were available    for choice of the                                                            displayed in reM time at the Mercury Network
astronaut--tlF,           UIIF    main,  and UHF       back-                                                          stationsfor the purpo_ of monitoring the con-
up--as    shown                 in figure 2-16.    Also, _ redundant                                                  ditions of the IL_,trona.ut and eritioM spacecra, ft
ground-to-air                    voice link is available      through                                                 syslenis              llS         the nii_sion                            progressed.                         The per-
the command                     receiver  vhannel.     An additional                                                  forniance                   of      the teienietry                             systeln               was       si_tisf,<to -
air-to-ground        comnmnication      link is available                                                             to|s"         as     silown              ill     figure                  `2-14.

to the astronaut         by keying   the low-frequency                                                                    Recovery  ,_y,_,tem.--The   recovery  system con-
telemeter     carrier.     It should   be noted that all                                                              sists of a IIF tran_'eiver    (1 watt),  one recovery
of tliese     links    use the niain      t)i<'one antenna                                                            pack'lge containing      the CW SEASAVE         beacon
tllrough    the u_ of a multiplexer.                                                                                   (1        watt),            It     [)ulse                n]odniated                       SARA             tt     beacon

    Performan('e   of the voice system during                                                                 the      (7.5         watts)>               and              it    pulse              Inod]llate(1                    Slg])ER              -

MA-6      mission  was satisfactory  as indicated                                                               in    SAil,ill                 t)eacon                 (91         waits),                      The         anten]]a             sys-

figure 2-14.                                                                                                          tems  used Ily the re(:;overy                                                  systeni are shown i]i
   tladar   system.--The  radar  systeni consisted                                                                    figure '2-15.  Perfornlance                                                     of tile recovery sys-
of C- and S-band beacons onlloar(l         tile space-                                                                teni has been slitisfactory.
craft,    l_;oth beacons were "oil"    eonti]]llOllSly
thro]]gho]]t          flight,  and
                              tile   either   or both
1)eacons could     lie interrogated      when   within                                                                    Tile sl)acecraft    instrunmntation       system moni-
]'a]ige of the apl)ropriate    ground station.     Per-                                                               tored    the astronaut's        ECG,     respiration      rate
for]llance           of        the           radar             systeli],               inohiding              the     and depth,       blood pressure,     and body tempera-
grollnd         trackhlg                 a]ld          contpliling                     co]iiplex>            wi/s     t ure in addit ion to certain      aspects of operations
satisfactory                  and            was       such          that          the        spacecraft              of the spacecraft        systems.     Locations      of many
orbital  trajectory                           was  well defined by the end                                            of the sensors are shown in figure 2-17, and the
of the first orbit,                          and continued    tracking  d]ir-                                         instrunmntation        list is shown ill table 9-III.
iil7 tim reinah]hig                          orbits resulted in only niinor                                            Ninety              oonnnutator                           segnidlits                   wei_          available                 for
changes lo orbit                      l)aranieters                   ah'eady               established.               data,          phis         seven              conthutons                          channels.                     The       con-
Radar           l)erforlnallce                        is       shown             ill       fi_'ll]'e 2-14              i incus channels                              were ]lsed n]ahlly for aerolnedi-
a]]d      is (li_'usscd                ill     more            detail         in        paper        6.                cal intern|alien                               and spacecraft    control-system
       Uommand                  ._.q._.tem. The                         CO]ll]nan(1                  system            perfornia]ice                       data.                   An             h]slrlnnentalion                              sche-
l)rovided          nlea]is            of      coin]nanding                     all       al)ort>          retro-       |italic            diagrani                    is        inohlded                   its         figlire         `2-18>          to
fire,     sliacecrafl-('l(wk                            (']ia]]ge,          or          it|sir|nile|ira-               show how tile different                                            nieasllreinenis                           were hen-
lion      calibration                  froin            tile      grout|(1,              if    necessary.              died. A                    16-ul]n               ca|hera                    ])hotograplled                        tile         as-
None of tile                  first          three of tim above conullands                                             tronaut's                  face         and              npper              tOl'_)          area          in     color           at
u+ere needed                   for       a('cOtlli)iishiilellt                          of the MA-(i                   36() frames/niin      ()]" 5 friunes/min,    depending     on
 ]nissioli.          '|'lie          oi]i)oard                 conlnuilid                  sysleni           was       the mission    phase.       The overall quality     of the_
exercised               by           ten           histr]ii]ienlalh)n-calili]'alion                                    photographs      was good;          however,    due to ex-
gtxmnd           conmiands                         during            the       iiii.,<sion           for       i]i-    treme variations        in the light intensities       in the

         TABLE                    2-III.--Spaceera#                                         lnztrumentation                                      and                 TABLE                2-III.--Spacecra#                                          Instrumentation                        and
                                      Ranges                ]or         the         M,4_                     Mission                                                      Ranges                   ]or          the         MA-6                Mission--Continued

         [All               data          commutated,                              unless                  otherwise                      noted.]                      [All             data       eommutated,                              unles,s       otherwise                noted.]

                                                                                                                           Instrument                                                                                                                                      Instrument
                                                                                                                                   range                                                                                                                                          range
                                                                                                                   (0      to       100 percent                                                                                                                     (0 to 1(_             per(.ent
                                                                                                                 full             scale          unless                                                                                                             full      .'_'ale       unless
 Events:                                                                                                            otherwise                noted)                                                                                                              otherwise                  note(1       )
 Tower                      release         .....................                                                       ()n-off                               Electrical                   functions:
 Tower                      escape           ro('ket           ignition_                                                ()n-off                               3 volt              referen(.e              ................                                      l(R)-percent                      full
 SI)a(.e(.ra    ft                   separation                  .........                                           ()n-off                                                                                                                                           _,ale
 Retroattitlnle                          command                        ........                                    l )ll-(iff                                Zero          reference                 ...................                                       0-percent                         full
 Retroro('ket                           firt,_ ................                                                     ( }n-off                                                                                                                                       scale
 Retrorocket                            a._,_eml}ly               jettison                .....                     ()n-off                                   7 volt            a-c bus,             volts           ................                           0 to 8
0.()._g            relay            ..............                                                                  ( ) [l-off                                d-c s, volts                .....................                                                 12.9         to     L_J.8
 l)rogue                     lmrachute                   delfloymcnt__                                              On-off                                    d-c      current                 3, anu_res                      .............                    0 to 50
Antenna                       fairing             release             ..........                                    ()n-off                                   l_ans         a-c          bus,        volts           .................                          95 to 120
Main                imrachute                       deployment                       ........                       ()n-off                                   ASCS                a-c     bus,        volts           ................                          .(h) to 125
Periscope                         retract           .................                                               ( _n-off                                  Isolated                  d-c Inls,              volts        ............                        13.3         to     _'23.4
Mayday                      .........................                                                               ()n-off                                   Standby                   d-c      t)us,          volts         ..............                    13.2         to _¢
Heat-shield                            deployment                     ............                                  On-off                                    Standby                    inverter                "ON"_             ............                 On-off
Main              parachute                      jettison               ............                                ()n-off                                   Astronaut:
Reserve      I)'_rachute           deploy                                      ........                              On-off
Pilot   abort ........................                                                                              ()n-of                                    Body              temperature,                           °F ............                          92.5         to 10,5.9
                                                                                                                                                              Body           temt)erature,              °F ............                                         92.6         to     106)
Ntabilizatitm                             and           co_ttrol           :                                                                                  ECG           #l 4.......................
C_mtrol                     stick         position               (roll)             _, (leg___                      ±12                                       Respiration                      ' .......................
('ontrol                    stick         position               ¢ pit(.h            ) t, (leg__                    ± 12                                      Blood   pressnre      4, mm                                      Hg ..........                    _       to        20;5
Control                     sti(,k       position                (yaw)t,                  (leg___                   ±14                                       Command       receivers    :
Oyro              outtmt                  (roll),           deg ...........                                         --1,30          to 190                   (_ommand                      receiver                    ON-OFF                   .......         On-off
Gyro              output                  (pitch),              deg ...........                                     --120           to 174                    Command         re('eiv(,r                                 signal                strength
Gyro              output                (yaw),              deg ............                                        --70          to 2,)0                       "A",  #v ......................                                                                 0 to         80
Scanner                       output             (roll),             deg .........                                  --37.5           to 33                   Command         receiver             signal                                       strength
Scanner                       output             (pitch),                 deg ........                              --38.5           to 3,3                    "B", /_v .........................                                                               0 to         _0
Scanner                       ignore            (roll)              ............                                    On-off
                                                                                                                                                              Environmental                              fum'tio_._:
Scanner                       ignore            {pitch)              ...........                                    ()n-off
                                                                                                                                                              Suit        inlet            temperature,                            °F ........                  39 to 116
ASCS                 slaving                signal          ............                                            On-off
                                                                                                                                                             Cabin                temperature,                         °F .............                         35      to     233
Roll            solenoid,                   high,          + .............                                          On-off
                                                                                                                                                              Suit         liressure,                  psia           .................                         0 to         15
Roll            solenoid,                   high,          -- ..............                                        On-off
                                                                                                                                                             Cabin                t)ressure,                   psia        ..............                       0 to         15
Pitch              solenoid,                  high,          + .............                                        0n-off
                                                                                                                                                             Static               pressure,               psia          ...............                         15.2         to --0.3
Pitch              solenoid,                  high,           -- ............                                       On-off
                                                                                                                                                             Coolant                quantity                   pressure,                   psig .....           213        to 4_;9
Yaw             solenoid,                   high,           + .............                                         On-off
                                                                                                                                                             O2 snliply                   pressure,                    1)rimary,                psig___         --50         to     7,500
Yaw             solenoid,                   high,          -- .............                                         On-off
                                                                                                                                                             ()2 supply                  pressure,                   secondary,                    psig__       --100          to 7,600
Roll           solenoid,                   low,          + ...............                                          On-off
                                                                                                                                                             (L partial   pressure,                                rain Hg ........                             --15   to           980
Roll           solenoid,                    low,         --_ .............                                          On-off
                                                                                                                                                             02 emergency      rate                              mode ............                              On-off
Pitch             solenoid,                    low,         -4-.............                                       On-off
Pitch             solenoid,                   low,         -- ...........                                          On-off                                    A eec lera tio _:
Yaw             solenoid,                   low,         + ..............                                           On-off                                   Acceleration,               A,                           (h)w               range),            g
Yaw             solenoid,                   low,          --_ .............                                        On-off                                      milts ...........................                                                                --0.415            to 0.375
Roll          rate              (low         range)            '_, (leg/see                .....                    --9.q          to 10                     Accelerati(m.                           A_              (high                range),           g
Roll          rate              (high          range)            _, deg/.,_,_                      ....             --25.5           to 31.5                     uniLq ............................                                                             --3.2         to 3.5
Pitch              rate           _, deg/sec               ...............                                          --10.3           to 30.5
                                                                                                                                                             Acceleration,               Ay                           (low              range),             g
Yaw             rate            _, deg/sec_                ..............                                           --+10.3                                     units ...........................                                                               --0.415             to 0.38
     t    (".onlnlntllted                         and          ('ontinnollS;                              eol|tinnous                     data         re-       s Comnlutat(_l                                Hnd          ('(Hltinuons;                   continuous                   (l-c   cur-
e(irded                ont)o:Jrd               only.
                                                                                                                                                             rent         and           d-c voltage                     recorded                onl)oard        ()lily.
     : Oontinuom_                             only;           recorded                    onboard                        only.                                       Continuous                        only.

      TABLE           2-III.--SpacecraJt                  Instrumentation                    and         conditions                   for         the      astronaut.                           In     addition,                       the

         Ranges/or                the     MA_6        Mission--Continued                                 astr<maut                   can          manually                         actuate                 a        control               to
                                                                                                         initiate              the         oxygen                emergency-flow-rate                                                 mode
       [All      data        eommutated,            unless     otherwise             noted.]
                                                                                                         to t)rovide                  an         adequate                   suit        environment                              in the
                                                                              I nstruinent               case            where              multiple                   plumbing                        or                electrical
                                                                                                         failures              m_ffht             make           automatic                      initiation                       of tim
                                                                        (0 to 100 percent
                                                                        full scale unless                emergency-flow-rate                                      mode                  inoperative.
Aeceh.rati_ms--Continued                                               othei'wise    noted )                   The          environmental                            control                   system                l)rovided,

Acceleration,            Ay (high                  range),         g                                     with         its      automatic                    ol)eration,                        an      adequate                        and
  units ............................                                   --4.0 to 4.9                      safe        enviromnent                          for        the       astronaut                        throughout
Acceleration,          A ....................                          --31     to 35                    the       entire        MA-6               mission.
Integrating            aeeelerometer                     signal,
                                                                                                               A      simplified                    schematic                       diagram                         of         the      en-
   ft/sec ..........................                                   0 to 565
                                                                                                         vironmental                        control              system                   is    shown                     in     figure
Equipment               temperatures:
                                                                                                         2-20,           and         the          system               is     discu_d                          in        more           de-
RCS automatic                    H_Ch line tempera-
                                                                                                         tM1        in l)_q)em                   3 and          5.
  ture low roll, clockwise,                      °F .....              --6 to 242
RCS automatic                    ILO, line tempera-
                                                                                                                Electrical                  Power               and           Sequential                            Systems
  ture       low         roll,       counterclockwise,
   *F ..............................                                   --11     to                                                         Electrical                Power               System
RCS manual      H_O, line temperature
   low roll, clockwise,  *F ..........                                 --12     to 9_60                        Figure            2-21              shows               the          spacecraft                           electrical
R(_S manual     H20: line temi_rature                                                                    power                system.                   Rech',rgeable                            silver-zinc                           b,_t-
   low roll,            c_unterelockwise,        *F ....               --29 to 2"2.4                     teries           of     both             3,01)0-watt-hour                               and            1,5fX)-watt-
Retroroeket              temperature,     op ........                  -- 16 to 140
                                                                                                         hour            ratings                 are       arranged                        into            three                 I)ower
IIeat-shield          temperature,                 oF ........         --140      to 2,470
Inverter          temperature,                    150 v-amp,                                             sources               to l)rovide                 a total                 of      13,500               watt-hours.
    °F .............................                                   --10 to 337                       Nominal                 di_harge                       rate           for         each            type                of      bat-
Inverter          temI)erature,                   2._d) v-amp,                                           tery         is 4.5          amperes                   lint         each          i)attel         3, is capable
   °F ..............................                                   --18     to 322
                                                                                                         of        supplying                     1)ulse         currents                   up         to        42         amperes
Transmitter               temperature,             HF,     °F___       8 to 320
                                                                                                         for        a few            milliseconds.                             Silicon                diodes                   in each
Transmitter               temperature,             LF,     °F___       --16 to 326
                                                                                                         positive               leg         of      all      batteries                     l)revent                      discharge
Onboard               time:
                                                                                                         of normal                   batteries               into           defective                 or low-voltage
Verner    (.lock,'   percent .............                             0 to 12
                                                                                                         batteries                   in      1)arallel                 configurations.                                     Tim           in-
Time since launch,           percent .........                         0 to 1G0
Time to retrograde,          percent .........                         0 to 100                          dividual               I)attelw                voltages                   and          the        total               current
Calibrate      sigmal ...................................                                                are         monitored                     in      flight             by          the         astronaut.                          In

      * Continuous             only.                                                                     event,           of     battery                  failure              or         equipment                            failure,
                                                                                                         he        can        m.mually                  switch               off individual                               batteries
 spacecraft                during   the              various           mission     phases,               or all battery                      power.
 definition               was reduced                at times.             Performance                          A        _lid-state                     static               inverter                 provides                         115-
 of     the      instrumentation                    system          was       satisfactory.              volt,        400-cycle,                   single-plut_                          Mtenlating-current
                                                                                                         l)ower             for the              spacecraft                   att,itude               control                   system
                     Environmental                   Control              System                         and             another                 provides                   similar                  power                     for      the

       ,ks      shown           in      fiKllre     2-19,      the        environmental                  environmentM                              control                  system.                   A         st tmdby                  in-

 control              system         is located          princil)ally                under         the    verter              provides                 redundancy                         for         either               of         these

 astronaut's                  supI)ort         couch.         This         all-important                  two        mMn              invertel_                 trod          can         tnke         over                for        both
                                                                                                          if noncritical                     ASCS                loads              are        switched                    off m,'m-
 system               1)rovides           an      oxygen           atmosphere,                 tem-
  l)eratm'e   control,     and  pressure      regulation                                         for      uMly.                The          sta,ndby                 inverter                  can         be            automati-
 the astronaut's       suit and    the cabin.        The                                      cabin       cally          or     mammlly                    placed                  in a.etion.
  and         suit     are     independent               redundant              circuits           for          Electrical                   l)ower             consmnl)tion                           for           tim            MA-6
  automatically                      providing           proper           environmental                   mission               is shown                   in the              following                       table:

     _   1_o   _


         _          QO




                     i      i


         _          v_


                                                                   PmVRE 2-17.--Location                    of ._ome spacecraft        instm_mentation                 sensors.


                                                                        (COM.,.ES'0                      J R _ [] >- _                           -
                                                                                                                                                                 COMPO_JN   D FM

                                                                                                                                                                                   -I TR*NSM,T'rER

                                                                                                                                                                                   I"'°"'RE°I I
90    MEASUgEMENTS                  AND       EVENTS|
FRO_:                                                          J

      ENVIRONMENTAL                       CONTROL              l
      SYSTEM                                                   [

                                                                             / EKO _l,_&-                       ''
                                                                                                                                RECORDER                                                  ANTENNA

      STABILIZATION                 SYSTEM                     /

      SPACECRAFT                   STRUCTURE                   J

                                                                                    RES_IR_T      ] ON

      SATELLITE            CLOCK                               J    /

     OF      THE     7     CONTINUOUS                 /
CHANNELS                  ARE      SHOWN:             --

     OTHERS              INCLUDE          RATE

     MEASUREMENTS,                        SOLENOID

     ACTUATIONS,                   CONTROL                                                                                                                       COMPOUND     FM   I                I



              CURRENT              MEASURE


                                                                                                                                                                  -v-vuvtIT.L.M_F.,  L
     MENTS,                                                              1                                                                                 E                         /
                                                                                                                                                                        "I "r,,ANSM,T'r.
                                                                        C Oiv_MUTA       T OR
                                                                                                                                                                         I_°''RE°-   /
                                                                        (COMBINES           ALL    90

                                                                        SIGNALS        ON       SINGLE                 r_l


                                                                             l_zGtr_ 2-18.--Instrumentation                  system        schematic           diagram.

                                                           0 2 SUPPLY                                         HEAT
                                                           SECONDARY                                    EXCHANGER
         FIGURE 2-19.--Approximate         physical   arrangement      of space_.raft   environmental        control   system.

                                 /     •


                       172GURE2-20.--Schematic         diagram      of environmental     control   system.

                                                                 MAIN          24       V DO BUSES
                 MAIN W.H.
         I 3 - :3000

                                                                 STANDBY                24,18,12,               8[ 6 V DO BUSES
             STANDBYW. H.
         I 2 -1500

                                                                  ISOLATED                 24, 18, B 6 V DC BUSES
                ISOLATED H.
              I-15OO    W.

         I            ,,,v,_. o Bu,
           _ov.A._ As_s ,,ooPS.,,,.
                        SCS       INV.

         I F_,S,_o _._,,_      OPS.  B
                         V,,_..00 ,,,. US
         i STANDBY V.A.INV. ]
              250                                                 W.H.
                                                                  V.A.        - WATT
                                                                              - VOLT               HOURS

                         FIOURE    2-21.--Schenmtic          diagram     of   spacecraft         electrical      power       system.

                                                  APPROX. 34 °                                                       APPROX. 34°
                                                                                                                                           .        l--
                                              4       5            6                                      7                            8
                                                                                                                                           i_       _2

               i,       BOOSER        AND SUSTAINER ENGINES FIRED
               2. BOOSER              ENGINE CUTOFF

               4. SUSTAINER CUTOFF                                                                                                                            /'


                    .   SPACECRAFT SEPARATION



               8. START RETROSEQUENCE
                        SIXTY SECONDS AFTER RETROFIRING RETROPACKAGE                                                IS JETTISONED
             _I0. DROGUE              PARACHUE              DEPLOYED AT 21,000FEET


                                    NOT JETTISONEDFOR MA-6 MI SS ION
                        _RETROPACKAGE                                                                                                          12

                              FIGURE      2-22.--Sequence        of major      events      for    the    MA-6     mission.
                           TABLE             2-IV.--_Tlethods                                 of Initiating                            or Controlling                     21lajor ._Iission                        Sequences

                                                                                                                                                                                                              Initiation                           capability
                                                                       Major            mission                events
                                                                                                                                                                                                   Auto-                   [ Ground[                                   Pilot

                                                                                                                                                                                                   matic                    __                                    __
          1      Booster          and      sustainer              engines               firing                .......
          2      Booster          engine         cutoff                       .................
          3      Tower          jettison            .................................                                                                                                                         X                     .....                                 X

          4      Sustainer            engine         cutoff         ................                                                                                                                          ®                               x                           []
          5      Spacecraft             separation                 ........................................                                                                                                   x                     .....                                 X

          6      Yaw        and     pitch        maneuver                   to orbit               attitude                      .......................                                                      X                             ....                          X

          7      Attitude          control          during             orbit       ..............................                                                                                             X                                                           X

          8      Start.        retrosequence                                                                             ...........                                                                          X                              X                            X

          9      Retropackage                  jettison           and         reentry              attitude                   control                      _                                                  X                                                           X

         10      ])rogue          parachute               deployment                    .....................................                                                                                 X                     .....                                 X

         11      Main          parachute            and        landing              bag           deployment                                .......                                                           X

         12      Main          parachute            release,          reserve             parachute                     ejection,              recovery            aids   activation                          x                                     __                    X

     ®        Refers      to    automatic              redundant                   system.                          []         Refers          to      indirect       control,             x     Refers              to      direct                  control.

   Both the d-c and a-c electrical                                                       systems                   func-                                                                                  F        FIRING        SIGNAl               ]

tioned well throughout     the MA-6                                                      miasion.                    Ex-                                                                                                    J
                                                                                                                                                                                                          [              LIFT Off                     ]

cessive temperature    rises of the                                                     inverters                   were                                                                                                    l
                                                                                                                                                                                                              BOOSTER SUSTAINER                       1
caused by a malfunction      of the inverter      cooling                                                                                                                                                 i     PO_RED FLIGHT                         ]

 system.    The inverter    design     operating       tem-
                                                                                                                                                                                                                   G [ GUIDANC[
                                                                                                                                                                                                                   800S TFR CUTOFF                    ]
 peratures   was exceeded   for both inverters         dur-                                                                                                                                                                 1
ing the second orbit.     Mttximum       inverter     tem-                                                                                                                                                [ BOOS_R          sEpARATION                    I
peratures    were over 200 ° F, somewhat           higher                                                                                                                                                         SEP    ]
                                                                                                                                                                                                          r BOOst[R SENSOR
than desigll temperature    ; however,    performance                                                                                                                                                          20 SEC TIME DELt, Y                        I
                                                                                                                                                                                                              TO_NTRRING BOlT FIRE
of the invertel,s during  tim mi_ion      was excellent                                                                                                                                                                      i
                                                                                                                                                                                                          L        TO_91-RRINGSEp                     j
and no adverse  effects due to the high tempera-                                                                                                                                                                            T
tures were noted during    postflight inspections.                                                                                                                                                                  RELaYs
                                                                                                                                                                                                          ] PeRmlsswe    ]
                                                                                                                                                                                                          I escaoe     .re
                                                                                                                                                                                                                  RocKET ]
                                    Sequential                  System                                                                                                                                                          [
                                                                                                                                                                                                          I       TOuR     S[DARATION                     I
    Figure    '2-'22 shows      the sequence       of major                                                                                                                                                     L
                                                                                                                                                                                                               sEo      l
                                                                                                                                                                                                          r To_eR S,-_,SoR
 events for the MA-6 mission.             The only excep-                                                                                                                                                       I
                                                                                                                                                                                                                     SUSTAINtR                            J
tion to the planned         sequence     occurred      during                                                                                                                                                      POV,_ RED FLIGHT                       ]

event    (9) as a result        of the astrona, ut being                                                                                                                                                                        I
                                                                                                                                                                                                          [        G E GUIDANCE
                                                                                                                                                                                                          !       SUSIAINER CUTOff
advised     to retain    the retropackage        during     re-                                                                                                                                                           L

entry    and     manuully     overrode      the automatic
sequencing      as directed    by instructions      from the                                                                                                                                                                                 SenSOR
                                                                                                                                                                                                                                       I CUTOFF    l

                                                                                                                                                                                       LPILOFS   C_                                          T]      I
                                                                                                                                                                                                                                       I I sec ,_ DeLA_
ground.     Figure     2-23    shows  the spacecraft                                                                                                                                                                   j
master   sequential    system.                                                                                                                                                                        [ CaP       _OLT
                                                                                                                                                                                                           aOapteR e_Rf]
   Redundancy       for the automatic    initiation  of                                                                                                                                               I       CAP ADAPl             RING SEP                  ]
spacecraft                 sequence              events    is furnished    by the                                                                                                                     [       PERMISSIVE               RELAYS                 ]

astronaut's                 ability            to initiate     events   manually                                                                                                                                             I
                                                                                                                                                                                                      [ POSIGRAD[               ROCKET FIRF I

by switches                     and        controls                and           by        ground-com-                                                                                                                    ]
                                                                                                                                                                                                      F                  CA_se_                               ]
manded    initiation                           of     certain   events by                                        means                                                                                                     ]
                                                                                                                                                                                                      [       PER&_ISSIVE REiAYE                              1
of a radio-command                                   link.    Table 2-IV                                         shows                                                                                      J
                                                                                                                                                                                                          SEP     l
                                                                                                                                                                                                      I _A_ Sf_,SOR
the       redundancy                    in initiation                       cal)ability                       for          im-
                                                                                                                                                                                                                                                              EXT[ND P[RIg. C( RE)
portant  events.   From                                   this tabulation    it can be
seen that the astronaut                                    has control    over all of
the           l)rimary            spacecraft    automatic     functions.                                                                                                         (a)   Launch                 and         orbit.
The           _tstronaut           also has indirect   control over the
                                                                                                                                                 Fmu_E            2-23.--Masier          ._equential                     diagram                      for          the        MA-6
impoi_.ant                  humch-vehicle                              functions,                        such                  as                                                        spacecraft.

                                                          SATELLITE CLOCK-TR I

                               GROUND   COMMAND 1
                                     RETRO          /                                                COMMAND
                                                                                            I PILOT RETRO       1

                                                          1                            1

                                             I PILOT RETRO 1                I T 3oSEC
                                                DELAY SW                        ME DELAY
                                                          I                            I
                                                                                                      I ATTITUDE PERMISSION     I
                                                    [ ATTITUDE      I                                          BYPASS

                                   30 SEC      1
                                HIGH THRUST!           RETROS
                                               ----I F,RE I   J
                                    HOLD                      i
                                                           sec DELAY
                                                         16o TIME I
                                                                              IPILOTSWITCHI                         [
                                                                                                                    I THIS PART OF THE AUTOMATIC
                                                               i                                                      SEQUENCE WAS PERFORMED

                                                   I RETRO SEP                                                       MANUALLY
                                                                                                                        HE    THE
                                                                                                                                    BY THE ASTRONAUT,

                                                       I                                                             cIrcUItRY IPILOtSwncHI
                                               [ RETRO       SEP1                                                            JEmsONInO OF
                                                       1                                                             the     _RETRO
                                            [RETRO       SEP
                                                  ASSEMBLY SENSOR_                                          ]        ASSEMBLY       SEP BOLT F'RE).
                                                                   I                                        I
                                                     sEc DELAY
                                                    15 T_ME I                                     l 30 SEC TIME DELAY 1

                                                    I                                             lrErRACT
                                        {ABOVE J                             .05GJ
                                                                       { BELOW
         I                                          I                          I
'_ASCS 12°/SEC                      sTABILIZATION
                             IREENTRY           I                             ORIENTATION
                                                                       [REENTRY         j
  ROLL RATE,                                        1
                                 _RSCS 7.5°/SEC     ROLL RATE, I
                                    PLUS RATE DAMPING                  I

                                                    (b)       Retrograde         and       reentry.

                                                          FiouaE       2--23.--Continued.

634401       0--62----,--_
                                                                       ARMED 2 SEC AFTERTOWERSEP

                                                                       J                                                I
                                                              ACTUATE] I
                                                      21,000 BAROSTATS                                          DELAY
                                                                                                           ZSECT_ME I
                         I                                             l                                                '
                                                                                                1 lo,0oo BAROSTATSACTUATE I
           PERISCOPE MORtaR]
      I _TEND   I I DROGUE FIRE                                                                                         I
                                                                    I  I           ]
                                                         DEPLOY ANTENNA [ SWITCH UHF TO DF MODE
                                                    DROOUE I lJETTISONFA'R'NOI                                                                                                                                      I

                                          I                                                 II                                                        j                                                         I
        RESCUEBEACON (ONIl                                                                                                                [EJECT SOFAR BOMB]                              i   INFLATE MAIN
                                                                                                                                                                                          I CHUTEEJECTORBAG
            AUTOPILOT(OFF)                I         SWITCH FROMBICONE
                                                    TO DESCENTANTENNA

                                                                                                [         12 SECTIME DELAY                            ]

                                                                       I                                                I            {ARM)
                                                I LANDING BAG EXTEND J I                             DUAL INERTIA SWITCHES I
                                                                                                J         TOUCHDOWN(SPLASH)                           J
                                                                                               I                    I
                                                                                                I DISCONNECT MAIN CHUTE j
                                                                       i                                                I                                                            I
                                                       TURN ON FLASHING                         I          1 MIN TIME DELAY                           J [           10 MIN TIME DELAY                               J
                                                                                                                        I                                                            I
                                                   L GHT SEASAVE BEACON                         I    EXTENDWHIP ANTENNA                               I             TURN OFFCOMMAND
                                                                                                                                                            RECEIVERSC AND S BAND
                                                                                                                                                            BEACONSHF COMMUNICA-
                                                                                                                                                          J TIONS BOTHTELEMETERS
                                                                                                                                                          [TAPE RECORDER, CAMERAS

                                                                                   (e)      Landing         and      recovery.

                                                                                       FIGURE 2-23.--Concluded.

engine cutoff, through  use of the                                                spacecraft                   sure.           At        this     time,         the       drogue              parachute                   is de-
abort handle when necessary.                                                                                   ployed               to     decelerate                    and       stabilize               the           space-
      The      performance                    of     the      spacecraft                sequenc-               craft.           At        about           ltl,000         feet,      the       antenna                  section
ing system               was      satisfactory                     during         the       MA-6               and          drogue          parachute                    are      jettisoned               by       the      sig-
                                                                                                               nals          from         another               dual           barostat             and         the         main
                                Landing                Systelm                                                 parachute                   is     deployed                  in      a      reefed            condition
                                                                                                              ol)ened           to       12-perce.nt                of     the      maximum                     diameter
      The      landing           system              consists              of    the     drogue
parachute,              main       and          reserve             parachutes,              laud-             for          4 se_'onds            to        minimize                the        opening                   shock.

ing         bag,       and       attendant                  functional                  systems.              The            nmin           I)arachute                    deploys                  fully            after           4

The         landing           system           is armed               when        the      escape             se_,onds              of      reefing.                A      reserve             l)arachute                   ]nay

lower         is jettisoned             during              exit      flight      ; however,                   I)e deployed                     I)y       the    astr<maut                    in    the      event            the

it    is not         actuated           until         the      spacecraft                returns               main           parachute                   is unsatisfactory.                           After              main

to     the         relatively           dense              1)arts       of       the       earth's             1)arachute                 <tel)i()yment                  , the       landing               I)ag           is ex-

atmosl)imre              , as shown                in figure          2-24.                                    tended            to       provide               attenuation                    of      the          landing

      The      landing           system              is normally                 actuated            at        load.            hnmediately                         after           ].u_ding,                the          main

an     altitude          of     about           21,000         feet         by    either        one            l)arachute                 is automatically                         disconnected                     and       the
of    two      barostats           which             sense          at most)heric             1)res -          reserve          para('hute                  is ejected.

  DROGUE                                             MAIN PARACHUTE                                  DEPLOYMENT

                                                                                   TENNA             CAN


                                                                                                                                 /-LANDING                  BAG
                                                           DISCONNECTED->_.__I                                                    _1_1__

RESERVE                   PARACHUTE                             JETTISONED__=!
                                 F[(_URE        2-24.--Sketch          depicting     u_,_e of    spacecraft     landing       systems.

    The drogue       parachute       is a 6-foot-diameter                                shield is held directly   to the spacecraft    by a
conical  ribbon-type         with a 30-foot-long        riser.                           mechanical   latch and the landing   bag is folded
The main and reserve             parachutes    are 63-foot-                              and contained     between   the heat    shield  and
diameter    ringsail      types,    either  of which      will                           spacecraft..          After      release, the heat shield drops
l)rovide a sinking       velocity    of 30 feet per second                               down     and         extends       the bag to its full length.
at sea level.                                                                            For a water     landing,     the bag attenuates      land-
   Tlm landing  bag is a rubberized-cloth                                assem-          ing decelerations       from     approximately     45g to
bly about 4 feet long.   Before    release,                            the heat          approximately      15g.
                                                                                            The drogue     parachute      deployed    at an accept-
                                                                                         able but somewhat         higher     than expected     alti-
                                                                                          tude      during      tile MA-6          mission.       Both    drogue
                                                                                         and main parachutes     were observed      by the as-
                                                                                         tronaut  to be in good condition     after    deploy-
                                                                                         ment.   The heat. shield released    properly      and
                                                                                          the landing    bag attenuated        the landing       loads
                                                                                          ,tbout as expected.
                                                                                              The "heat-shield-deployed"           signal,    that     is
                                                                                          sent to the telemetry        system,    is furnished       by
                                                                                          either  one of two limit switches            which     sense
                                                                                          the movement       of the heat-shield       retention     de-

  HEAT _                  _                          ',ZJ_--"SHIELD-DEPLOYED"             vices      as shown       in figure        _-25.     I)uring     tile    or-
 S HIELD-_ _                                                     LIMIT SWITCH             tlital flight portion    of the MA-6       mission,                     one
                                                                                          of these swit('hes    sent a "shield-deployed"                          sig-
FZOUaE   2-25.--Details          of    heat-shield        deployment         mech-
                  anism    and        sensing     switches.                               nal     to the      ground       monitoring         stations.       Post-

flight testsof bothlimit switchesevealed   that              rather than    parallel    and    rigged      farther     away
(meswit(.hwasfaulty andcouldgiveintermit-                    from actuation     points.
tent "shield-del)loyed" signalswith tlle shiel<l                 (2) A "maneuver'"        switch      will be installed
lo('ked place.                                               on the AS(_S pane]        to i)ermit      the astrommt     to
               FUTUREPLANS                                   interrupt automali(_      orbital    i)itch-prece,_sion.
   Asa resultof minordifficulties    experienced                (3) The 1-pomM-thrust            chamber    assemblies
duriu_lhe flight of MA-6 tile following modi-                are 1)ein_ moditied to make         them nloi'e reliable.
fi('alions will be ma(le to subseqnen!   Sl),lceeraft    :      (4)   The check    valve between        the ('oolanl   tank
     (1) The limit swit('hes   whi('h indicate      that     and inverter   cold    plates    ix to be rel)la('e(1     b), a
the heat shiehl is released will I)e wired in series         nmnual  valve.

                    3.     LIFE          SUPPi)RT     SYSTEMS   AND                                              BIOMEDICAL

By RICIIARD S. JOHNSTON,    Asst. Chie/, Li/e Systems Division, NASA Manned Spacecra]t Center; FRANK H.
    SAMONSKI, Jr., Lqe Systems Division, NASA Manned Spacecra[t Center; MAXWELL W. LIPPITT,            Li[e
    Systems   Division,  NASA    Manned Spacecra]t    Center;   and MATTHEW I. RADNOFSKY,    Li]e Systems
    Division, NASA Manned Spacecra[t Center


   This report contains   :_ de,_'rril)t, ion of the en-
viromnental    control  system      and outlines     the
system   perfornmnce     ill flight.   The                       pressure
suit is described    and the signific'mt                        pressure-
suit   developments       aceonq)lished               to d:rte           are
shown.      The    survival     kit, is            described            and
special   emphasis     has been phtced on newly de-
veloped    surviwtl     it(m_s.   The MA-6     bioinstru-
mentation     is di,_ussed      _md the development       of
the blood     pressure     measuring    system   is re-
viewed.    The    p:tlx, r is presented    as separate
sections  for these four areas.

                                                                                  I"IGURE     3-l.--Pr()je,.t           Mercury        enviromnental          eont    r4)l
          Environmental               Control       System

                                                                                  spacecraft  under    the as(romtut     SUl)l)ort c(ru('h.
   The    Project        Mer(.ury      enviromnental               control
                                                                                  The astromtut    is ch)(hed   in a full 1)re_sm'e silt(
syslem      (I"(':S)has      l)eell described      in previous
                                                                                  1o provide     protection     in the event of a t,abin
1)al)ers (refs. 1 and _) and, therefore,             this I)al)er
                                                                                  decomI) ression.
only     reviews      tilt. system    design     and outlines
                                                                                     The 1)ressures      in the ('abin and pressure   suit
sl)e<'ific MA (; system (.onfigurations.                The test
                                                                                  are maintained      at 5.1 psia in normal   flight with
lrroffram       for tlre ECS         was l)re_'nte(l       i. (he
                                                                                  a 100-percent                    oxy_zen atnrosl)here.      The system
MR 3 flight relrort            (ref. 3).     Flight     data for
                                                                                  is designed                    to control    ,tutomalically     the en-
 lhe MA-(; fliffht are l)resente(l           in this pal)or.
                                                                                  vironmental                   con(lit ions within the suit, and cabin
                      System        Description                                   throughout     the, flight.      Manmtl  controls    are
                                                                                  t)rovide(1 to emtlrle system el)era)ion    in the event
   The    M er('ury       environmental             ('()ntrol      system
                                                                                  of automatic     control    malfunction.   In describ-
l)rovides a ]iwtl)le environment          for the astronaut
in whMr     total   l)ressure,     gaseous     composition,                       ing the enviromnenta]      control system, it ran be
                                                                                  considered  as t we sul)sys(ems   ; the |)ressure-suit
and (eml)eralure      are mat))lathe(l,       and a breath-
ing oxygen     supply     is l)rovi(le(l.    To meet (he_                         control  system    and (lib (':d)in system.      Be)It ()f
                                                                                  these system ol)erate     simultaneously     from com-
requiremenls      a ('h)sed-tyl)e    enviromnental       con-
trol   system     was     deveh)l)ed      l)y Aille_arch                          mon coohtnt    water and ele(,( ri('al supplies.      The
Malmfa(:lurinff      I)ivision     of Garrett,     Corpora-                       coohm!   water   is stored    in a tank with a pres-
lion mulet      a M<:I)onnell     A ir(.raf( ('orl)oration                        sm'ized bhHhter    system                        to facili(ale   weightless
sullcont rac(.                                                                    flow of water   irrto (he                        heat exchanger.       Elec-
   The environmental                control       system        shown        in   tri(!al    t)ower              is supplied        from      an onboard             bat-
 figure   3 1 is located        in the lower          portion        of the       tery      supply.               Oxygen       is sut)plied            at an initial

                                                                            tim light and correction      of the water flow rate
                                                                            will prevent/lie     heat exchanger     from freezing.
                                                                            In the gas side of the heat exchanger,             water
                                                                            callers  pickett u t) in the suit are conden_d       into
                                                                            water dro])lets   and are carried      by the gas How
                                                                            into a mechaldeal     water separation     device.  The
                                                                            water    sep'trator   is a sponge    device   which    is
                                                                            .squeezed l)eriodieally    to remove     the metabolic
                                                                            water front the system.      This water is collected
                                                                            in _Lsmall tank.      The constant    flow rate of the
                                                                            'ttmosphere     is maintained    by a COml)ressor.
                            CASIr_                                              In the MA-6 spacecraft         a constant    bleed ori-
                                                                            fice was provided        between     the oxygen       supply
  }#IGURE3-2.--S(.heimttie             diagram of tile Mer('ury             and    the pressure-suit       control     system.       This
           enviromnental              control syt_tem                       constant    oxygen    ttow was in excess of metabolic
                                                                            needs and thus provided          't continuous      flushing
pressure       of 7,500 psi          from    two     spherical     steel    of the pressure         suit to insure adequate            oxygen
tanks.                                                                      partial      pressure.       In normal         operation_       suit
                Pressure-Suit        Control     System                     l)ressure     levels were maintained             slightly    above
                                                                            cabin pressure         1)y metering       this excess oxygen
   The    pressure-suit           control        system   provides
                                                                            flow through          an exhaust       port     in the demand
breathing     oxygen,           maintains         suit pressuriza-
                                                                            regulator.        In the event of a cabin decompres-
tie] b     removes     metaDolic    products,     and main-
                                                                            sion the demand          regulator     would automatically
tains,     through    positive ventilatio]    b g_is tempera-
                                                                            establish      a referenced       pressure      of 4.6 psia for
                                                                            the exhaust: port of the regulator,                  and thereby
    As shown    in figure             3-'2, tim l)ressure   suit is
                                                                            suit pressure        would be maintained             at this pre.s-
attached   to the system               by two c()nnections,     the
                                                                            sure level.        The addition        of the oxygen          bleed
gas inlet connection         at the waist and the gas                       orifice is the major          ECS change for this flight.
exhaust      at= the helmet.      ()xygen    is forced   into
                                                                                An additional         mode of operation           is provided
tile suit distribution       ducts, carried     to the body
                                                                            by the emergen('y           rate wove.         This valve 1)ro -
extremities,       and permitted      to flow freely    back
                                                                             vides au open-type         pressure-suit       operation     simi-
over the body to facilitate           /)ody cooling.     The
                                                                             lar to aircraft        pressure-suit       systems.       A fixed
oxygen    then I)as_s            into the helmet           where the         flow of oxygen         is directed     through       the suit for
metabolic     oxygen,           carbon   dioxide,         and water          ventilation        and metabolic            needs.       The     re-
wtpors     are exchanged.      The gas mixt ure leaves
                                                                            mainder    is dumped    into the cabin.     This system
tile suit and passes through         a debris trap whe]'e
                                                                            is used in the event the pressure-suit             control
1)articulate     matter  is removed.      Next, tim gas is
                                                                            system    fails and also during       final    stages     of
scrubbed      of odors and carbon dioxide in a chen}-
                                                                            descent.    The other coral)orients     of the suit sys-
teal canister     of activated   charcoal     and lilhimn
                                                                            telu ar(_ ch)sed off during   this mode of operation.
hydroxide.           The gas then is cooled by a water-
                                                                                 ()xygen     is SUl)plied from t we tanks, each con-
evaporative           type     of heal    exchanger      which
                                                                             taining      sutficient     oxygen   for more     than     98
utililizes  tim      vacullln    of space lo cause the cool-
                                                                             hours.      The tanks are equipped          with pressure
ant water to         boil at 'tpl)roxinmtely     3,) _ F. The
                                                                             transducers        lo l)rovide data on the supply      pres-
heat-exchanger             exit gas temperature        is regu-
                                                                             sure.     The tanks are connected          in such 't way
htted       through     matnlutl ('ontrol   of the coolant-                  that deple!ion        of lhe primary    SUl)I)ly automati-
water        flow valve.      The resulting      steam is ex
                                                                             cally provides        for   supply      from       the   secondary
hausted        overboard.     The steam exit teml)erat      ut'e             bottle.
on the       overboard    duct is monitored      by a thermal
                                                                                                      Cabin    System
switch        which actuates    a warning     light when the
 duct lemt)erature    drops    below 47 ° F.                                    The e:d)in     system     controls      cabin    1)ressure   and
    The light is on the list ronalll's  lmnel and                   pro-     temperature.         A cabin relief valve controls   the
 vides a visual indication    of excessive   water                  flow     upper limit      of cabin pressure.      This valve per-
 into the heat        exchanger.            Proper    monitoring       of    mits cabin       pressure   to decre,'_se with ambient,

plvssure  maintaininga differentialpressure fo                                                           E    /]SUNLIGHT
5.5 psi dm'in_the climbof the vehMe. This
valveseals   thecabinat 5.5psia. Ill addition,a                              TEMPERATURE,
manual(leeomI)ression    featureis incorporated                                     °F         .... CABIN TEMPERATURE                   7            REENTRY              '

in this valve to t)ermit the astronaut to dump
                                                                                IO0 f
the   cabin      pressure    if a fire or buildup            of toxic
                                                                                   I/                                               INFLOW VALVE AND /
ga_s  occurs.                                                                    SO_      SUIT INLET                                EMERC__NCY RATE_I,/
   A cabin-pressure   regulator     meters                     oxygen                    TF.MP ER-A'FURE
into the cabin to nrlintain     the lower                    limit of
                                                                                    O          OtOO                O_.OO     05:00                  O4:OO             O5:OO
pressuriz_/tion        at   5.1      psia.      A manual       recom-                                                TIME, HR:MIN

pression  feature  is ineorpor,_ted     in the regulator
                                                                             10I(I.URE 3-3.--Variation               of smit      and       cabin         temi)eratures
for, cabin repressurization       after   the eal)in has
                                                                                                                   with   time.
I)een decompressed.
    C'd)in temperature    is maintained  1)y a fan and                       changer   was operating  near its maxinlum        ea-
be'it exchanger      of the same type as that         de-                    l)aeity for the existing  conditions.     Even     so,
scribed    in the discussion     of tlm pressure-suit                        the mean cabin air temI)erature       was steadily
sysi era.                                                                    re(lueM       during            the    mission         after           the      first     hour
   Postlanding         ventilation           is provided     through         in orbit.
a snorkel    system.  At 20,000 feet following      re-                          The suit inlet temperature      (fig. 3-3)                                          varied
entry,   tim snorkels   open     and ambient    ,_ir is                      betw_n     65 ° F and 75 ° F during    the orbit                                        phase.
drawn    by the suit compressor     through  the inlet                       The astronaut       reported  a eoolant     flow                                         of 1.7
valve.     The    gas ventAlates    the suit   and    is                     ll)/hr  to tile suit heat exchanger       an(t a                                          steam
dumped        overboard         through        the outlet    valve.          exhaust  temperature      of 60 ° F.     These values
                                                                             are 1)oth higher     than anticipated     and contra-
                            Flight      Data                                 dict each other    since freezing     of the heat ex-
    Lau.neh.--The   launch    pha_    was nornlal       in                   changer    would  be exl)eeted  at this flow rate.
that cabin and suit pressures      maintuined      a 5.5                     No explanation    of this anomaly   can be offered
psi differential  pressure   above ambient       during                      at this time.
ascent aad held at 5.7 and 5.8 psia, respectively.                              The coolant tank was charged    with 95 pounds
    Orb#.--Cabin    and suit pressures     were 9min-                        of water        before           the     flight.           The         coolant-quan-
tained at 5.7 .tnd 5.8 psia, respee!ively,    through-                       tity   indicating       system      shows _ usage          of 7.2
out lhe flight.      The dehty     in these l)ressures                       poml(ls.       Postflight     tests revea.led      t_ usage of
th:lt lms been observed       in previous    flights was                     11.8 pounds.         The difference       in calibnttion       and
al)sent_ in this fli_zht for" three possible     reasons:                    final system temperatures             ean account      for about
   (1) Low       eal)in    leak'tge     (le_   th'm     500                  3.8 pounds of the 4.6-pound               dimrel)aney.         The
                                                                             remainder       is considered      .tx) be instrument       error.
   (2) Oxygen       from the bleed orifiee in exce_u                             The      prim_u-y-oxygen-supply                                pressure               indi-
of .lstronaut    requirements                                                cates a usage rate of 0.13 lb/hr         for the duration
   (:_) Possible      leakage      from    the se('ondary                    of the flight.   Postflight   tests eonfinn this us,_ge
oxygen        supply                                                         rate.
                                                                                The secondary       oxygen     supply     exhibited    ,_n
    The oxygen        partial      l)ressure     measurement
                                                                             unexplained    decay in pressure      of approximately
 agreed     with     suit     pressure       within     0.2 psi
 dlroughout      the flight.      This wdue is within tile                   1'2 l)ercent of t.he total supply.    This decay was
                                                                             first noted at }m elapsed      time of 1 hour and 40
 aeeuraey   of tile instrmnent.
                                                                             minutes.     An apl)roximation      of the time when
    The eal)in air temperature     (fig. :_-3) fluetu-
 ated between      90 ° F and 104 ° F as the space-                           the leakage           began   is difficult, since the bottle
                                                                              was serviced           to 8,000 psig 1)rior to flight, and
 craft passed from darkness     into sunlight.       The
                                                                              the nmxinmm        indicating   v'due of the pressure
 astronaut   reI)m_ed  that at ]east five attempts
 to reduce eat)in air temperature     by increasing                           transducer    is 7,500 psig.     Postflight    testing  re-
 water flow to the eal)in heat exeh:mger       resulted                       vealed     no appreeial)le    leakage     from     the see-
 in the illumination    of the excess-water        light.                     ondary    sut)ply.   No explanation                              of this          problem
                                                                              is available    at this tinle.
 This    light      indicated         that     the   cabin    heat     ex-
                   Reentry ndPostlanding
   Thenmximmn cabin temperature              during    re-
ent D" and l)ostlanding      was 103 ° F, which was
tolerable.   The suit inlet temperature       increased                                                              I. NECK RING
to 86 ° I? during    the postl'mding      phase.    This                                                             ?. HELMET  TIEDOWN
value is reasonable     since tile air temperature      in                                                           3. PRESSURE  SEALING
                                                                                                                          ENTRANCE  ZIPPER
the landing        area    was 76 ° F (r_qative             huniidity_                                               4. NECK ZIPPERS
                                                                                                                     5.WAIST  ZIPPER
56 percent)         and    the suit. compressor             raises the                                               6. INLET VENTPORT
teml>erature       by approxinmtely               111° F.                                                            7. PRESSURE  INDICATOR
                                                                                                                     8. BLOOD  PRESSURE
                          Pressure       Suit


   The pressure   suit used in the MA-6        flight
                                                                                      Pit, uRn 3-4.--Pressure      suit torso.
was deveh)ped   from the l ;.S. Navy MK-IV        full
lwessm'e  suit m'mufa('tuved   I),v the B. F. Good-                        l)(mning       and    dolling    of the     suit      is provided
rich Co. This basic suit was _lected      by NASA
                                                                         th]'ough   a pressure-sealing     entran('e    zipper
in ,July t(,_59 for use in I''t      Mercury      after            whi('h extends   diagomtlly   across    the front     of
an extensive       evaluation    l)VOgVam of three full                  the lorso  from the left shouhler       down to the
pressure    suits.    This initial   suit evaluation      was            waist.     Two frontal     ne('k zit)pers and a (qr('um-
('onducte(t     t>y the IT.S. Air For,'e         Aerosi)aee               ferential   waist    zipper     are als(i provided        for
Medical     Imtxwat,wy,      Aeronaut      ical Systems    Di-           ease in donning       aml doffing.
vision.     Many design        clmngt_      have l_en made                   The pressure-suit      ventilation    system is an in-
to the suit since tile start_ of the Mereut)"            pro-            tegral t)ari of the torso se('tion.          A ventilation
gram     and, indeed,      changes       and modifications               inlet port is ]o('aled at a point just above the
are still being invest igated          to 1)rovide its g(x_(I            waist on the left side of the torso se('t ion. This
a suit     as I)ossible     for the ])roje_'_t Merem T                   inlet port is (:onne('ted to a manif,)hl   inside the
[lights.     In this paper,       the sttit is briefly     tie-          suit where vent tubes lead to the body extrem-
scribed an(l emphasis         is pla('ed on showing        the           ities. These tubes are constructed       of a he]i(,al
developmental       evoltlt ion of the present pre_ure                   spring covered hy a neol)rene-eoated      nylon fal)-
suits.                                                                   rie that contains l)erforations    at regular  inter-
   The full pressure    suit consists                 of five basic      vals.   Body ventilation     is provided      1)y forcing
components,   the suit tor_), hehnet,                 gloves_ boot.%     oxygen   from the environmental         control    system
'rod undergamnent.                                                       into the inlet and distributing        this gas evenly
                                                                         over the body.      Tl,e ventilation     system     in the
                      Pressure-Suit        Torso
                                                                         Mercury    pressure   suit was espe('ially     developed
   The suit torso,       as shown     in figawe 3-4, is a                to insure compatibility     with the environmental
elo_ly      fitted coverall  tailored    for each of the                 eontrol system.
astronauts.        It covers   all of the body       except                 The suit torso se('tion ('ontains       several   items
for the head and hands.             The to]-_-oosection     is           whi(.h   have been develol)ed          spe('ifi(.ally      for ])roj-
of two-ply      construction      : an inner gas-retent, ion             e('t Mercury.        They are 'Is follows:
ply of neopl_ene and neoprene-coated              nylon fab-                 B_oeot_neetot'.--'I'he       bioeomleetor          provides      a
ric and an outer ply of heat-reflect, ire, alumi-                        method       for      bringing        medical         data     leads
nized nylon fid)rie.            The hehnet    is att_'mhed to            through     the pressure         suit.      The lfioeonneetor
the torso section        by a rigid neck ring.          A tie-           consists of 't mullil>in         electrical      plug to which
down     strap    is provided        on this neck rin K to               the biosensors        art. t/ermanently         attached,      a re-
l)revent    the hehnet        from rising     when the suit              eeI)taele   plate      mounted       to the suit tm.'so see-
is pressurized.        Straps     are al_) provided     on the           tion and an outside           plug which is eommeted               to
tor_o section       for minor sizing adjustments            of           lhe spacecraft          instrumentation         system,       lVith
le_ and arm length            _tnd circumferences       and to           this system, the t)io_nsor             h:trness     is fabricated
prevent        the suit    from      ballooning      when     pressur-   with the biooonne('t,w             as an asseml)ly          and no
ized.                                                                    additional     electrical      cmmectom         are introduced

  ;_=AC'.K           A._,v         ¢iHi!t            _ :_.;:C,(_A_!',
                                                                                                      llecl¢ dam                 is rolled              and       stowed                oil tile           out_ide
                                                                                                      of lhe             neck          rin_z disconnect.                           After           the      astro-
                                                                                                      ilaut  removes    the helmet                                        in       1)rel)aril.litm for
                                                          I. INTERNAL             PLUG                egress_ he um'olls the neck                                       dam        umil it provides
                                                         2. RECEPTACLE                PLATE           a seal around  his ]leek.
                                                         5. UNDERGARMENT   WITH                          /'n+._'._..r<:/_.t;../or.--A                               wrist-moun(ed                            l)res-
                                                              SPACER PATCHES
                                                                                                      sure iMicai.r         is v,.r_l                         .rl the left arm.                          This ill-
                                                                                                      dicator   provides  the   "lStl'Ollall|                                      II t'l'OSS        check         <)n

                                                                                                      his suit-l>ressuz'e   level.       The                                     hldicator                 is cali-
                                                                                                      brate<] from 3 to 6 psia.
           FI(_URE    3-5.--Bioeonnector                  (installation).
                                                                                                                             _ ('
                                                                                                         lllood-/' r_',_.._,+'_ <,,,<'cio+'.--A                                          ',+i>cci'll tilt ill,,..
                                                                                                      is provided      Oll tilt' suit lorso                                             which      lterinits
inio the          tra,sd_,'(,r  syst(,nL.  Ill operatio.   (@.
                                                                                                      l)ressurizni                ion        Kits     it() tie    fed     into          the      })]ood-l)l'eS-
:>>-5) the          nMe illlernal     plug is inserted   inside
                                                                                                      silre        ('lilt'.           A   h(ise        lea(linT           frOlil         ill(,     cuff'     is   al-
the suit          recel_ia'le  and locked into place.      The
                                                                                                      tll('hed            1_) lhis            conno('lor            (turin          7     mill       donniu7".
imenM             plu_ F,r<>trudes throu/.[h the SLliI tO rd-
                                                                                                      After            ilsirol/alll               iliTl'oss       hlio         i]ie     :;pa('e('l'aft            ihe
low tile           sl)acecrafi  plug to I)e alta'he(l.     The
                                                                                                      l)ressurizillion     _(llll'Ce is aline]led                                        i() lhe ('Ollnec-
biocOlllieclor           systt'nl           hits    [)roven          l(i     |_   a     I]lll](t]l
                                                                                                      I<ll" Oil file outside of tile suit.
more sat isfa<'tory                 comlector           thai/ lhe previously
used biopateh.                                                                                                                                           Helmet
  :Vee.4_ [.l_._.-A                  eoliica]         rubller              neck    d,ml          is
aitached           to tile   torso          ne<'k    t'hl_        _ls s]lown          ill   fiE-         The              hehne/, lls.-_,nlbly, shown in tlgure 3-7,
                                                                                                      consists             of it reshlous,     ilill)l_c_.rilllie,d Fiberglas
ure           'I'll(, l>Url>ose of this m,ck dam is Io
           3 6.
i)reverd     wMer      frolll erllerin K the suit h] evenl                                            ]lll rd          she,]]:         iui        individually                 lnoidt_|             cllis|lltbie
of     water    eKress      with   the heltneI   off. The                                             hnl)acl                 lhierl         il     ven iilillion              exhaust               OililY;            ll

                             (a)      ,_tor(_l      l_t,_ilion.                                                                           (Ill      Unrolled            position.

                                                                              PIO'[T_,E 3-6.--Neck            (laln.

                                                                         band       cent roller.        The     glove,         like   the torso      sec-
                                                                         tion, has a two-ply        construet  ionIthe     inner gas
                                                 I. NECK RING AND        reteniion      ply and ;m outer restrqint          lilY. The
                                                 2. PLEXICLAS VISOR      inner     lily is fabricated      by dipping     a mold of
                                                 3, PNEUMATIC VISOR
                                                      SEAL               the astronaut's      haml into Estane        materi.d.   The
                                                 4."ON-OFF" VEOR
                                                                         outer       ply is fabricated  from  one-way  stretch
                                                 5. DEFLATE BUTTON
                                                 6, VISOR SEAL HOSE      nylon       on the back of the htmds and fingm_ and
                                                 7. VISOR SEAL BOTTLE
                                                 8. MICROPHONES          a neoprene   maierial   injected into a nylon fab-
                                                                         ric in the lmhn of the gloves to prevent    slippage
                                                                         in turning   knobs,   and so forth.    Lacings       are
                                                                         provided   on the back of the glove to allow for
               I_C, URE 3-7.--Itelmet         assembly.                  minor adjustments.      Two wrisl restraint     straps
                                                                         are provided   to form t>reak poinls and                            tlmrel>y
                                                                         iml)rove pressurized  glove nlot)ility.
visor   _aling        system;           and   a comnnmicat.ions
                                                                             Minature       needle-like   red linger     lights     are
                                                                         provided      on lhe index and middle            fingers    of
    The hehnet         vi_r   sealing      system consists          of
                                                                         both gloves.         Electrical   power   is supplied       to
a pivoted         Plexizlas     visor,    a pneum'ttie         visor
                                                                         t he miner ure light s by a lmti cry l>aek and switch
seal, and an on-off            vimw write.         Closin_        the
                                                                         on the back of the _loves.         These lights provide
visor    actuates      the valve aim causes           llUtOlnatic
                                                                          instrument-l>anel       and chart ilhunination       before
inflation      of the vi,,_n" seal.        The visor seal re-
                                                                         tlm     astronaut       is adapted          to night          vision.
mains      inflated     until  a, deflation     tmtton     on the
valve is nlammlly       actuated    by the astronaut.                                                      Boots

2'he valve has ira>vision      for attachment    of t.he                       I,ightweight,        aluminized,           nylon-fabric            I_ot's
visor-_al  ¢as-supply-bottle       ho_.
                                                                          with remits-shoe-type                soles were             Sl_eially    de-
   Tim hehnet communication             system consists                  signed  for the Mercm                 T l)ressure            suit.     These
of two independently           wired AI('--10      earphones             boots    resulted   in substantial   weight     saving,m,
with    sound     attenuation       CUl)S and t.wo inde-
                                                                         provided      a comfortable    boot for flight,    and ;t
I)endently      wired     AIC-10,      newly      developed,             flexible   friction  sole which aids in egress fron|
dynamic,      noise-cancelling        mierol)hones.       The            the spacecraft.
microphones       are installed      on tracks which al-
low them to be moved back from the center of                                                         Undergarment

tlm lmlmet        to pemnit      eating       and    proper   place-        Tim undergarment               is '1 one-piece,           lightweight,
                                                                         cotton         garment      with    long sleeves    and legs.
                                                                         Thumb          loops ale    provided    at the sleeve ends to
                                                                         prevent     material from riding     up t.he arms dur-
     The gloves     attach     lo i']le sui t.t m,'so 'It the lower
                                                                         ing suit donning.        Ventilation   spacer   patches
forearm     by means   of a detent     ball-bearing                       (.see fig. 3-5) of a trih>ck construction     are pro-
lock.   The gloves have been specially    develol>ed                     vided on the outside       of the undergarment            to
for Project   Mer<,ury  to provide  the maximum                          insure ventilation     gas flow over certain     critical
in comfort      and    mobility.     E'wly   cent, rifuge                areas of the body.
programs     dictated    the requirements       for this
development.        Poor   mobility    in wrist    action                                      Pressure-Suit         Support

when the suit is pressurized        caused an impair-                        Prior to and after   astronaut,     donning     of t,be
merit in the use of the three-axis          hand      con-               pressure   suit the complete      as,_mbly     was pres-
                                                                         surized   and leak checked       at 5 psig, and at, 5
    A pressure-sealin_      wrist    bearing     was in-                 inches of water differential      p_,ssure.      This test
corporated       to improve    mobili D, in the yaw-                     console provides    the pressure     control    and leak-
control    axis.   The one-way    stretch    material on                 't_re nmasurement,          system        required.
tim back of the gloves impl't>ves nlobilit.y in the                            During        astrommt          transfer           front    the       suit,
l)ilch and roll axes.                                                    dressing  room to the                 launching            pad, a light-
   The gloves have curved    fingers so that when                        weight,  hand-carried,                portable           ventilator pro-
pressurized  the gloves assume the eomour    of the                      vided suit cooling.

   Constant           eoinmunications                         are         maintained           developed.  This rel)ort           presents a brief descrip-
with the astronaut,  during    this transfer                                     by uti-       tion of each of [hese              items and the develol)-
lizing port able communication      head_ts                                      carried       mental     1)rograms.
by the astronaut              insertion  team.
  In the MA-6                 flight, the pressure                        suit    _iwed                                     Liferaft

more      as a flight          suit since               the     cabin  l)ressure
was       maint'tined.           Astrommt                     comments      indi-                  Early in the Mer('ury          program      it was (te<'ided
                                                                                               that improvements          couhl l)e made in the (lesignl
cated   that        the l)ressure                suit        was      satisfactory
                                                                                               of the PK-2        raft.      These       improvements           in-
throughout          the flight.
                                                                                               chided    improved       stability      in rough        ,seas and
                                                                                               ease in 1)oarding.          A contract       was let. in No-
                      Survival             Equipment
                                                                                               ventber 1!)59 to fabricate          several   ]iferafts     wlfieh
                                                                                               ineorl)oraled     bow ballast      buckets   under    the
   The MA-6                sI)aceeraft        was            equipped    with a                raft for stability       and a defla(able   aft section
survival kit              (fig. 3-8)         made             u 1) of standard                 to simplify    boarding.     Tests of these falls with
                                                                                               a subject     in a full-pressure     suit proved    that
                                                                                               they were very difficult       to capsize  and easy 1o
                                                                                                  With   the configuration     settled   ut)on , an at-
                                                                                               tempt   was made      to reduce    the weig'ht     of the
                                                                                               r_ft by the enq)loyment      of a lighter    1)ase fabric
                                                                                               and coating and C()_ cylinders.
                                                                                                  Sea    tests   were    again         performed         by      NASA
                                                                                               1)ersomml     attired     in a Mercury      pressure      suit
                                                                                               using liferafts       fabricaled    of conventional      fab-
                                                                                               ric, t)uilt in accordance       with the NASA       designls.
                                                                                               The sul)ject was able |o sit on one side tube of
                 FIOURE     3-8.--Packed            survival          kit.                     the raft without       capsizing    it.
                                                                                                  An inhouse    program        was then  initiated    to
1)ep'trtment       of l)efense      (I)O1))    surviwd     items
                                                                                               iml)rove    the raft   reli'dlility   and   reduce    its
and     other     items    re('ently     developed      by the
                                                                                               weight t)y decreasing     tile mmfl)er of fabrication
NASA.         This survival      e(luil)men(    is carried    for
                                                                                               seams through    the utilization    of new materials.
emergency           recovery  ('ontingen('ies     an(l has not
                                                                                               Figures   3 l0 and 3-11 are l>h<>to_'raI)lls of the
been used          in the three re:tuned      flights to date.
                                                                                               rafts deve]ol)ed  by NASA.
                                     Contents                                                     Test results indi(.ated     satisfactory      or superior
                                                                                               perf<)rmance     when COml)ared with conventional
   ('ontents         of     the      survival               kit     are      shown        in
                                                                                               rafts   or rafts    deveh)l)ed      (o date for NASA.
ii_ure      3 9 and :Ire as follows                     :                                      The new unit was signi[i<'antly          lighter   than con-
    Sea (lye marker                              Sigmtl mirror                                 vent iomll rafts,    l>acke<l to al)<lut 1/_ the thick-
    Surviwd    flashlight                        Zinc oxide                                    hess, and when inflated         provided      over 3 square
    Shark   chaser                               Soap                                          feet of a(hlitiona]    sl)a('e for the occupant.         This
    Food container                               Medical            injectors                  raft (.onlained   only          1 seam        as opposed           to 11
   .lack knife                                   First-aid            kit                      seams in the previous          rafts.
   Sun glasses                                   SARA             1 [ beacon                      Tw<) sino'le-seam          rafts       were      fat)ricated     and
   Pocket    waterproof                          Nylon lanyard                                 strength      tested to 5 psi and shal)e      retention
     matches                                     IAferaft
                                                                                               after    24 hours    with 2 psi.    These  rafts    were
   Signal   whistle                              Water    container
                                                                                               then     packe(1 and sul>jecte<l   to the shock,       ac.-
   Sm'viwfl   knife                                                                            celerat ion, t eml)erature , vibrat ion, vacuum,      and
   The newly developed      items in(dude                                     the flash-       oxygen       conditions       specified     for tile Mercury
light, liferaft,   water container,   and                                    automatic         sl)acecraft.       After     passing     these tests, the rafts
medical self-injectors.    Also, a newly                                     developed         were reinIlated,        rel)aeked.     'm<t considered    flight
life     vest,    not contained             in the survival                      kit,   was    items for the MA-6 mission.

                                                                             BL,,.CK AND                    P-Hi ._( PP.'OI'C.C-_,,a.p_


                                                                        FmU'RE            3-9.--Surviwd        kit     eomponeuts.

                                                                                                             realized,          since        when          filled      with       (; I)OUl_(ls          of
                                                                                                              water, The b:,g takes                    ii I) spa('e         already         unusable
                                                                                                             in I,he ]ifentft kit..
                                                                                                                 Figure         ;_, 12 show,_          the         water      container         in tim
                                                                                                             unintt:ne(l,             untilled       condition.               Water         is forced
                                                                                                             ml(ler        pressure          inlo     the ('oniainer               t)y      means       of
                                                                                                             i lm one-way               pre_sm'e           valve      ._hown       in i Ira ]()win',
                                                                                                             middle,         h,fl-hand           :edion.            The     :l._t ton:ira      drinks
                                                                                                             through            the      phlsti(',         spiral         tube.       An      E._lane

    FIOURE      3-10.--Liferaft                  showing          stabilizing             buckets.

                                   Water         Container

     The     origimd              Sl)a('ecraft             wat_,r ('ontainers                    were
two     inflexible                1-pound           l)l;l_ti(     . ('a_e:        _'(mtaining
3 t)o/m(ls          of     water            each,       wilh       a total            weight           of
8     polmds.             It      was        determined                   tha!        a    flexibh,
water        haft     might             t)e installed             in the          liferafI            kil
which        would             provide           both        inflighl           and       survival
drinking            water             and       reduce          overnll          weight              nn(l

      P,y fabricating                   these       items        of neoprene                 ('oaTed
nylon         fabric,              an       immediate                savings                of       l_(t
l)Oml(ls         and           22()      cubic          inches          in       volume              was                        FIGURE 3-11.--Liferaft                      top   view.

                                                                                                                                     BLACK               AND                    .r,+i                  ,_ _-'_ .... :..'_,'i, .=.: ;
                           G TUBE                                              VALVE

                                                                                                                                                                                                                                                                      - go                            I

                         FIGURE 3-12.--Water                                         container.                                                                                             FIGURE 3-14.--Life                                   vest.

liner williin lhe                                     lm_            insures               iasleless waler.                                    The             second                 nlodel,                   wil h lninor                        inodifical                      ion and
Figure              3      1:/       shows                  how              tilt,         water            contltiner                         SliIipieinentiir?,"                                     ieslhu£               _ I)ecl/lile                         the         Slalidai'd
t):lcl<s        into            the          survival                       kit.            The            literati                  is        ttiThi                 ilenls           of        equilinienl.
placed           (m            lop         of          lhe            waler               ('(mlaim_r.                                                  [iltel'n'/|                     ('ill'}_)]l                 dioxide                     It('llllliill_£                       (levil'es

                                                                                                                                               were                   (lesi_£ned                        io         redu('e                    hulk                  and             wei_hi.
                                                       Life           Vest
                                                                                                                                               Lib,filler                      weiTlii                 coaled                fllltri<'s                were                tested              alitl
     As 't result                   of the              MR-4                recovery                  operat            ion          in
                                                                                                                                               Olle,             was             selected                         (5          oz         liVlOll                    with              1.5             oz
which           lhe        listronau[                       had           io niake               an enier_eney

exit, without                      his survivltl                          kit, ii l)e('lune,itpl)arenl                                                A              pa<'kel io slow                                     the          vest              was                devehii>ed.
lhal         lilt elilel'l£elIQV                       floilttion              device              wits required
                                                                                                                                               Tile             present                   ('Olifigiil'aiion                             (fiT. :/-14)                           is trape-
|o      mainlltiil                 |lol;ifrioil                 in        It water-filled                         pl'eSSlll'e
                                                                                                                                               zoiditl_                   5-      Ily         4-         I)y       %          tl_-       1-ill('li                  in       lhickness.
suil.          In        order              Io         prechlde                    or       reduce                the         pos-
                                                                                                                                               The              ]m('kel                 and              vesl            wei/}l               less               (]ili]l        I      pOlllld
sil>iliiy           <>f sin|liar                      silualions                     of     this          nalilre_                lhe          (().9,9               Ib)         aiu|            Colilllin                   an      oral             inllaler                  in addi-
NASA                inslhuled                         lhe       developnlenf                          of      ii inhiht-
                                                                                                                                               fio]l                 to        tile          i]lfel'llilI                    ('arlton                 dioxide                       ('hill'_e.
turized                 life           vest             enillioyin_£                            the         foilowhi                  7
                                                                                                                                               Presenlly>                             lhe            ]rocket             is affixed                        to         lhe           suit         be-
<'rileria           :
                                                                                                                                               low             tile         neck               rhlT.                 A         liulvar(1                    is provided                               io
       fl)      _,[ininlil]                 bulk                (less         than           21i ell         in.)
                                                                                                                                               preclude                        a('('idenlil]                       loss ulmn                      hiflltiion.                          Plaee-
       {7)      Minhna]                      weiThi                    (less          lhan            1   lb)                                  nient                  tesls            of            lhe          llackltl£e                  huli('llie                      the           <'best
       (_:_) ]lilillilllit]                     iiltel'fel'ell<'e                         with            fli_hl                  efli-
                                                                                                                                               area             1o t)e as sa! isfiietOl'y                                          ItS the ]oweI'                             ]e 7,           Tile
<.ienc.v                                                                                                                                       ellfil'e               llilii      ('all               lie oliened,   inflated>   and (|Olllle(]
     Two         Imsi('            ('Ollfi_'lll'al                   iOliS wel'e falwi(.aled,                                     lille        wilh                  Olle        hali(i                 ill less lhali     10 se('oli(|s when
a. Siliiliie             liltlt;        ,_iniilar                    lO     It ski          belt,          lhe       second
                                                                                                                                               ilttire(l                  hi lhe             |)ressllre                  suii.
It bell        wilh             hlfhlled                 hooks               (fi_.          3     14).             The              in-
                                                                                                                                                      Tests                    were                  liilt(|e          ill        the          oliell                 sea           froln                 II
flliillble,             |lOOl,:s           wel'e                consirucled                        1o l)i'ovide                           It
                                                                                                                                               ]aliliCii.                      The           iesi          sulljeci                th'sl         swain                     al)olll           with
positive                7l'llsl)          1() flit'              wel/rel"S                  silollillel,'s;                   ells)"           ihe           presslire                      siiii            in      lhe          ilitll('l             condilion,                           then
donliin_                 an(1           dot|hi              7        fealures;                   Itn(I        adeqliitle                       a('lualed                        lhe            flolalion                      device,                  donned                        if,       and
tlolitti(m                  chara('terisl                        i<'s          whh<ni(                      hnllairinc
                                                                                                                                               opened                      lhe          zililier                  1o his              suit.                  "rile            Stlil          ._OO11
l-eSclle,        i'e('ovel'V,                   oi'     swininlin                    7 of        lhe       I1_|     l'Oltlilll.
                                                                                                                                               lilled                 with             wlller                liild           the,       subjecl                      swain                 lll)olil
                                                                                                                                               unhindered.                                    The            "subject                   lhen               was              instructed
                                                                                                                                               1o l'elllOVe                           the            vest         while              lied            io           a safety                    ]hie.
                                                                                                                                               lie,         wlis            ilnai)le                  io reliulin                    on        lhe               Slll'fllce            lit|less
                                                                                                                                               hehl             there             l/y the                safely               line.
                                                                                                                                                      Final                     aceeptllnce                            testhll£s               > ineludin¢                                   high
                                                                                                                                               shock>                      a(,<,elel'aliOll,                             heal-cold;                              va.Cl.ltllll+                 alld
                                                                                                                                               vibration,                             were              perfornle<l                       in        accordance                               with
                                                                                                                                               the             relluirenients                                for         all         spacecraft                             hard,          ware.
                                                                                                                                               The              life           vest          was             carried                by        lhe           astronaut                        dur-

            FIGUItE 3-13.--Water                                 container                 in survival                  kit.                   ing           fhe,          MA               (; flight                  but           was           not              used.

                 Automatic          Self-Injectors

   The     survival       kit     contained          four      automatic
self-injectors      which contained     medica.tions   for
p,_in, shock, and motion        sickn_s     and a stimu-
lant.     These injec.tors  were developed       under an
NASA        contract+    The injectors   are, stored in a
small     package.      One end     of the injector      is
equipped    with _t red safety                cap and the other
end contains    the medication                and needle. Upon
removal of the safet.y pin, the injector   is armed.
By pressing   the needle end of the injector      into
the pressure  suit, the needle is extended  through
the suit into the skin and the medication       is re-
leased.     The resulting    hole in the suit caused an                                   FIGURE 3-15.--Flight            sensor harness.
insignificant    suit; leak.   In the MA-6 flight: the
astronaut     did not use any of the inj¢_'t.ors prior                         to    support      a    disc    of    40-ntesh        stainless       steel
to, during,    or after         the fight.                                     screen, 30 mm in diameter                    and approximately
                                                                               2 mm above the skin.   The                   center conductor            of
                        Postrecovery          Kit
                                                                               a, miniature-type               coaxial        cable     is    brought
    Each      of the  MA-6      recovery                      ships      was   through    a. strain           relieving        projection       in the
equipped       with a post recovery     kit                  which      con-   rubber ring and soldered to the screen.                A piece
                                                                               of therm,dly       shrinking     plastic    tubing   seals the
  ttigh   cut gym         shoes         Toothbrush                             ('able shield at the entrance         into the ring to pre-
  Flight    jackets                     Razor and            blades     and    vent the entry of moisture.
  T-shirt                                 creqm                                    Before the elect rode is applied           to the washed
  Shorts   (briefs)                     Combs                                  and shaved skin, a coating            of elastoplast      adhe-
  Socks                                 Wrist    watch                         sive is applied      to the 1x)ttom surface of the elec-
  Handkerchiefs                         Pressure-suit-hehnet                   trode 'm(1 alh)wed         I<) dry.     The ring cavity         is
  Sunglasses                              carrying            case             filled with a paste composed              of bentonite,     cal-
  Wash cloths                           Postftight           coverall          cium     chloride,     aud    water.      The electrode         is
  Soap                                                                         then    'tpplied     and the cavity          of the ring        is
                                                                               checked:      voids are eliminated;          then the assem-
                                                                               bly is scaled      with tape.     A 4-inch    square     of
                            Introduction                                       moleskin     applied     over the entire   sensor     area
                                                                               completes     the installation.
   The biosensors    used to monitor    the physio-                               The sig'nal from the ECG electrode           is trans-
logical state of the pilot during   the MA-6 flight                            mitted    via the coaxial cqble within the pressure
are essentially   the sanle Its those used on the                              suil to the biocomlector        and then to the ECG
l)revious    311l 3 and MII-4           sul)ol'lfital  flights                 aml)lifiers       in    the    spacecraft           instrumentation
with the exception         that  for the first time the                        package.      I)ifferential  amplifiers with high in-
astronaut      blood-pressure        measuring        system                   l)U( impedance        and _zoo(l common   mode rejec-
(BPMS)       was used.       (See tiff. 3-15.)                                 t i<)n are used to raise the si;znal to (hat required
    A detailed     discussion     of the electrocardio-                        f()r inlm(t()     the sl)acecraft    telemetry    system.
gvanl, body-teml)erature,      and rest)iration     sen-                       E('(;  measut'etnen(s     are discussed    in paper 9.
sors can be found       in the report on the MR-3
                                                                                                       Respiration        Sensor
[ti+zht (ref. 3), and these sensors      will be only
Iwiefly treated   here.    A more complete      discus-                             In   order    to    measure           respiration        rate     and
sion of the I_;PMS is included.                                                del)th , a thermistor        atmmometer                 detecting    the
                                                                               flow of the expired      :tit" was used.                A thennistor
                Electrocardiographic                Sensor                     with suflh_ient    era'rent     through               it to maintain
  The ECG     sensors              consist of rings composed                   its teml)erature al approxinmtely                         °
                                                                                                                                     '+2900F in still
of silicone ruhber.                The rings  are constructed                  air was n|otmled     ill a small                 plastic    enclosure

that wasattachedto oneof tile microphones                          method     utilizes    essentially  the same principle
within the tiehnet. A fun,nel-shaped  opening                      used in clinical      sphygmomanometry,       namely   an
facing the pilot conducts a portion of tile ex-                    inflatable    occluding     cuff on the left ann.    The
pired   air aeross    the heated     thermistor,  and              cuff is inflated     by gas to a pressure   in excess of
through    exist vents in tire back.    When the flow              expected    systolic    pressure.   As the pressure   de-
of air cools the thermistor,     the resistance   change           creases     slowly, a microphone           placed      under the
causes   a voltage    var'iaiion    across    the sen_r.           lower half of the cuff over the brachial                   artery
 This voltage      el,tnge    is sensed by a snla]l pre-           transduces      the Korotkoff       sounds     (ref. 5).      The
 arnl)liiier    mounted     on the cable leading         from      signal     from the microphone             is amplified        and
the sensor and this signal ix t r'ansmil ted through               mixed with _ signal from a pressure                  transducer
the pressure-suit        biconnector      to the spacecraft        which transmits        the cuff pressure.           In order to
instrumentation         package.                                   find    the arterial      pressure      it, is necessary          to
    The respirat     ion sensing     system does not yiehl         identify     the points of inception         and cessation       of
 data      from  whi<'h tidal      vohnne     ean be deter-        the microphone          si_ml      on the cuff pressure
mined.       The microphone           to which the sensor          signal,       which         are      the      systolic        and           diastolic
is altaehed     is pivoted    so that it can t_+ adjusted.         pressu     reds.
When the mi<'rol)hone          is moved, the signal from              In order to develoi> a t>l<_d pressure          measur-
the sensor      varies because       of the (.han_'e in the        ing system     (BPMS)      for spacecraft     use, a num-
volunie     of air passing        across   the thermistor.         ber of problem       areas had to be considered        :
The resl)iration       data have trot been fully satis-               (1) Pih)t safety and comfort
faetot:y    to (late.     Therefore,     an improved       re-        (2) Establishment         of the accuracy         of the
sl)iration       sensing    system     employing       tire im-               nleasut'ement     coml)ared    to clinical    and
i)edan('e      l)neumo_raI)h       prineil)]e     is pre+ntly                 direct meUmds
being      (levelol_d      tamer     an NASA           Manned         (3)     Operation              in a full-l>ressure                suit
Sl)aceeraft        Center    eontraet.        Details    of the       (4)     Operation    on an active                     subject        in a noisy
impedance           pneunmgraph         are    published      in                environment
reference      4.                                                     (,5)   Compatibility       with spacecraft,          systems
                                                                      (6)   Compatibility       with the receiving           facili-
                      Body   Temperature
                                                                              ties at Mercury      Control       Center and the
  The body temperature       prol_   is a thermistor                          Mercm T Network           stations
mounted  in a special rectal catheter.    The cathe-                   The original   concept    of the BPMS           (fig. 3-16)
ter is a small plastic    cylinder   :tbout          3 mm in       was an automatic        system, which would be initi-
diameter   and 25 mm long from which                 the ther-     a,ted from a tracking        station     through       the com-
mistor projects  approximately     2 ram.            The ther-     mand   receiver,    by an automatic      sequencing    de-
mistor,      catheter, and lead wires        are dipped   in       vice onboard      or by the pilot.      The automatic
liquid    l'ttex to a len_h   of about        90 cm to pre-        system   incorl)orated    special   safety    circuits  to
vent, the entry         of moisture.       The thermistor          dump the cuff i>ressure if the cuff stayed above
forms one arm          of a resistance     bridge which is
excited by 400 cps current     and which is located
in the   spacecraft    instrumentation     package.
Body temperature    data are discussed   in paper 9.

           Blood-Pressure      Measuring    System

   In April      1961 it was decided       to institute      a
program      to develop a device to measure        arterial
pressure.      It was hoped      that a system        could
he developed       in time for the first orbital     flight.
After     a survey    of the cur_nt    state of the art,
the decision      was made to use the new method
then currently    under development.      An inten-
sive effort to design, develop,  and test the flight
hardware      was started    in June    1961.    The                FI(_URE      3-16.----Blo('k       diagram       of     automatic           BPMS.

60mmII_zfor more                   than 2 minutes.         This fea-             Dr.         Geddes                observed            in reference              5 that          if
turo provided              for the situation          in which      the     the microphone       signal    is filtered so that                                             only
 pilot was un<'onscious              and tile aut croat ic sysWm            frequencies  1)etween       32 and 40 cps are                                                 used,
failed         to bleed off tlre cuff t)rl_sure.            The cuff        the various    artifacts      <lue to mmements                                                  and
|)l'e,'g_llFe.    in the automatic         system was decrea@d              ambient   noise  h'vel                              are         greatly          attenuate(t,
 in a linear mamwr               from 220 Into llg" to 6tl mm               while the <'Oml)(mem                               that         allows        the discrimi-
Ilg by a spe<'ial pressure                   regulator     in which         mtti()n    of   the systolic   and   diastolic     points    is
the reference             sprin_     tension      was varied      by a      l)assed.      Somel ime prior to tlte inception        of the
 motor-driven            cam.    Tile pneumatic         system con-'i, this ()hser'vatior_ was c(mfh'nled.           For
sisted of an oxygen                storage      flash, solenoid      fill   flight     use il Sllecially     daniped,      piezoeleciric
vah'e,         niotor-driven       regulator,       dunip    _flenoid       nricrol)hone                   was       develope(1.                The       ilislrunieul           is
valve, cuff pressure   transducer,                 and suit. refer-         lit)olit     3.5         cni      in    (tiarneler"          and        0,5   cni    thick      and
mice manifold.      The regulator,                 dump solenoid            is so   conslrii('led      liuil    sensitiviiy      to noise   erller'-
valve, and pressure    transducer   were referenced                          ing fr'oirl the side away fr'oni the skin is greatly
to a manifold   connected    thr_mKh a flow rest ric-                        reduce(|.         The niicrophone           sigiul]    exists from
tot to the l>ressure-suit      sy_em     to prevent dif-                    lhe suil tiir'ouKh            t]le t)ifx.oniiecior       and enters
ferences     between     cabin     pressure     and suit                    the iunplifier         in lhe t>l()od-presslrre          llnit.     Tile
l)ressure  from causing     large errm.'s and to allow                       Ill'MS     anil)liller      ('()nsists of a sliielde(1 pr,eanl-
mettsuremenis      in the event of tire los,,; of cabin                      plifler anl] Iwo liiTh-Kain              anti)lifters     which de-
l)ressure. After considerable                 testin K it, was de-          i erliiiile. I he respl)nse cha raclerisiies. Each ani-
cided to wear the cuff inside                   the" suit because
                                                                            l)]itler' ix designed      to have 7really   atlerlnated
feeding's    laken with the cuff oulsi,le, of the suit                      resl)onse oulshh'   l]lC :_2 1() 40 CpS pass     1)and by
showed     lar_ze errm=s due to tim <'oolin_ ducts                          means of resistor-<'almcitor       filtering <'ircuits in
within    the suit.    The problenl        of enterin_    tire              each feedlmck     h)ol).   The aml)litler      output    is
snit with a pneumatic           line to inflate the cuff                    gated so that iliiless a signal of sufficient              am-
required     extensive   develol)ment.         A fitting was                pliirrde    is pr'esenl   lhere   is no olitplil si$1al, and
<levised that is comforlable,         reliable,   and easily                this   gal ilrg   FeSlll|S in it rrlarked reduction     in the
disconnected       for sl>aee_+raft e/tx-_ss.                               miipui     noise h, vel for iniprow, d readal)iliiy          of
  During     the      testing of the preliminat   T system                  i he signal.
on astronauts          and other fli_'ht personnel    it be-                      The        cliff         l)r'essui'e        is      nlelisllred         tiy    a    potenii-
came evident          that the standard     5-inch clinical                 Oiileler-fype                    tr'arlsducer               liowered           by     two      nler-
cuff was unsatisfactory   t>ecau_: of its stiffness,                        Cill'y lmi:ieries  to tzive the zero-centered           +1.5
bulk, an(t the fa<'t thai arm movement      was re-                         volt output necessary      for input to the te]emeter.
stricted.  A new cuff (fi_z. 3-17) was devised by                           The signal from the pressure          transducer      passes
                                                                            through      a miniature    transfornmr        where it is
                                                                            mixed with the output fr'om the nlicrophone               and
       NYLON _'__
                                                                            then   on to the output        clipping      circuits    that
                                                                            protect             the telemetry   system     from                                      exce_ive
                                                                            voltages              that can cause    cross-channel                                        inter-
 +//      :""
                                                                                In order [o compare      this method    with direct
                                                                            arterial  nleasurernent,   a special centrifug'e   unit
                   FIOURE    3-17.--BPMS         cuff.                      was fabricate<l       and inslalled   on the human
                                                                            c'ellll"ifllge             lit    the        Universily                 of ,qoir/hel'll Cali-
the NASA      which   has proved   t. be acceptable                          fornia            (USC).                    A    _,ries          of      tests were     l)er -
-n all points    and is almost   mmolieeal)le    in its                     f(lrme<t by personnel      from I:SC,      NASA,    Mc-
uninflated  state.   Tests were per'formed    to con>                       l)<>nnel], and :\iRcsearch.        StPojecis  equipped
pare the new cuff with the standard               cuff and                  with the Ill'MS    oli lhe riKht arlil and an arterial
the resulting      data    were identical.      It is felt                  ('athetel' Oll the ]ell at'hi vcere tested at various
that the new cuff tylle has apl)lication             where                  acceleration  levels.     Spot checks were also made
comfort,     light  weight,    ease of application     and                  with a <'linical    cuff' and stethoscope.     The re-
un rest ricted arm mot ion are desired.                                     sulls showe(1 thai ;it lg the BI),'I, IS nieth<x1 read

about,   5 mm           lower         on systole            and     about     5 mm
higher     on diastole       compared      with   the direct
arterial    readings.
   There     is an increased     _'atter    in the points as
acceleration       increased    which    is thought     to be
partly   due to the "eyeballs-down"           position   of
the subject    causing    a pooling     of blood in the
lower arm.       Comparison     of the data from the
BPMS      with clinical     and arterial    tests can be
summarized       as follows:    The      BPMS      is more
accurate    than   the clinical    method     when both
are compared  with the direct arterial  measure-
ments, and the BPMS    readings  compared    with
the clinical   readings      are higher    on systole and
lower on diastole,      a fact which is probably          due
to the increase    in sensitivity     of the microphone                                     FIOURE   3-19.--Manual       BPMS    flight   equipment.
over the stethoscope.
   In order   to test. the system further         as well as
                                                                                        velop the BPMS       as late as 1961 resulted    in the
to obtain baseline       data on the pilots,       a centri-
                                                                                        system being a retrofit     item instead  of planned
fuge unit was installed         on the centrifuge      at the
                                                                                        spacecraft     equipment.       A number      of    late
U.S.    Navy      Aviation       Medical      Acceleration
                                                                                        changes    were made in the configuration        of the
Laboratory        (AMAL),                       Johnsville,                Pennsyl-
                                                                                        system   to reflect          developments   in the space-
vania.     Various   noise                  and vibration                  problems     craft  equipment.            The area originally  selected
were encountered       and                   solved.     The             tests were
                                                                                        for the mounting  of the BPMS       was proved un-
most     useful        in the testing              of the proposed             flight   desirable  due to egress  difficulty.     Alternate
amplifier,      and they also provided     the first op-                                areas selected   required  repackaging       of various
portunity       to obtain pilot comments      on the de-                                components     and finally resulted    in the elimina-
vice.    It    was during   these tests that'the    pres-
                                                                                        tion of the gas pressure     source,    regulator,    and
sure-suit   fittings                and    special          cuffs    were     devel-    motorprogramer      and the installation      of a hand-
                                                                                        pumped     inflation system     with a simple  orifice
   Concurrently                    with    the      test        program,       prob-    to release cuff pressure    (figs. 3-18 and 3-19).
lems    in spacecraft    integration        were   being                                    Subsequent      flights    will be provided          with a
pursued    by the McDonnell        Aircraft    Corpora-                                 BPMS       requiring       only a switch         actuation      to
tion.   The decision  to start the program         to de-
                                                                                        initiate    the cycle.       This     system     will contain
 F__[_UOCCLUDING                   MANUAL _                                             the gas pressure         source     for cuff inflation,       the
           FF                     INFLATION z.-.                 {_t fErRYI
                                                                                        regulator,     and the orifice         to relieve    cuff pres-
                                     BULB               PRESSURE _
                                                                                        sure and will allow a larger               number     of deter-
       /-MICROPHONE                II ORFICE_,__ TRANSOUCER__
                                                                                            In order to measure           arterial    pressure     with-
                                                                                        out adding       telemetry     channels,      the input to the
                                                                                        channel      carrying      the sternal        ECG     lead was
                                                                                        switched      to BPMS         during     blood-pressure       de-
                                                                                        terminations.         The band width required            for the
                                                                                        BPMS       is somewhat        greater    than that required
                                                                                        for ECG and it: was necessary               to modify     the re-
                                                    _             TO SPACECRAFT         ceiving   equipment      to insure           legible  readout.
                                     FILTERS -_/                    TELEMETRY
                                                                                        Blood pressure      measurements             are discussed     in
    FIOIIRE    3--18.--Block              diagram          of   manual      BPMS.       detail in paper 9.

              b34401     O-62-4

1.   JOHNSTON,                 RICHARD              S. : Mercury                      Lile        Stlpport         Systems,           Life    Support              ,qy,qtem._        for   Space         Vehicles.             (Presented
        at      the     IAS          28th          Annual               Meeting.                New        York,       .Tan.    25-27,        1(,_;0),        SMF           Fund       Paper        No.      FF-25.
2.   GREIDER,           HEBERT               R.,     and             BARTOX,                JO}IN       R. : Criteria           for      DcMgn           of    tile     Mcrc_lry           Enviro_mental                 Control         Sys-
        _em--Mcthod                     o]      Opcratio_                     o_d        l_csuTts          of    Mu_cd          Systc_          Operation.                  Jour.       Aerospace            Meal.,     vol.      3_   no.      9,
        Sept.         1961,      pp.        839-843.
3. WHITE,              STANLEY                C.,    JOHNSTON,                       RIC}IARD              S.,    et    ,_l. : Review           of   Biot_edical                    ,gystems       for       MR-3       Flight:         Proc.
        Conf.          on      Results              of         the         First         U.S.         Manned           Suborhital            Space       Flight,            NASA,          Nat.      Inst.     Health,           and     Nat.
        Acad.          Sci.,     June         6, 1961,               pp.     19-27.
4.   GEDDES,           L.      A.,     HOFF,             It.     E.,        HICIIMAN,                 D.._I.,      and      ._IOORE, A.         G. : Tllc             l)_lpcdallce             Pneumograph.                Jour.        Aero-
        sp_l(.e       Me(1..         vol.     ?,3. no. 1. Jan.                     till2,       pp.    2Y_:l:_
5.   GEl)DES,          L. A.,         SPENCER,                 _V. A., and                  ItOFF,       H.      E. : Graphic           RecordD_g             of      the    Korotkof]            Sounds.            American          Heart
        Jour.,         vol.     57, no.         3, Mar.                1959,       pp.      361-370.

         4.    LAUNCH-COMPLEX                                 CHECKOUT                    AND                            LAUNCH-VEHICLE

By B. PORTER BROWN, Mercury Launch Coordinator,      NASA Manned Spacecra/t Center; and G. MERRITT
          PRESTON, Chie], Preflight Operations Division, NASA Manned Spacecra]t    Center

                               Summary                                       launch           complex                          was       basically                designed           to sup-
                                                                              port  Atlas  I)                                 operations.   Both  the                              complex
    In smnmary        this paper       has pointed     out tile              •rod the launch                                  vehicle, however,  were                              modified
l)lannin/     required    to stlpport      tile launch    com-               to provide     various   and specific     features    that
plex and vehicle for the MA 6 operation.                   For-              were necessary      for a manned     spacecraft    opera-
tunately,     all modifi('ation       and emergency        type              tion.   A brief description      of a standard     launch
considerations        were not activated          dm'ing     tim             complex    and launch vehicle is given first so that
operatioli,    tIowever,   the l)aper   has indicated                        the special   features    for Mercury      will be more
tlle necessity    for such    items   in supi)ort     of                     reaxlily recoglfized.     Figure   4-1 shows _ stand-
manned      spacecraft    operation.              It is not the in-          ard Atlas D launch       complex.      The term "com-
tent of this l}aI)er to sug_'est                 that all possible            plex" includes                              such facilities   as the blockhouse,
coml)inations       (}f occurrem?es              were though!     of          fuel and liquid                              oxygen   storage, electrical   power
and planne<l          for.         Such a conclusion     can only
be reached            after        considerable   experience     is                                                                                                                  BLOCKHOUSE

gained   from many such operations.               The suc-
cess of MA-6,         however,      indicates     that  the
                                                                                         f               /'-_.           TOWERv _-.
                                                                                                                              2                          _                         ......
planned,   concept,   test procedures,      and check-out
and preparation      techniques    were sonnd and that                                        _                     "   "_.      I,A     t'-_TEST            VEHICLE                  _

no additional       major    modifications      are neces-                    /i:                               _               _                   "                         /'
sary   for support            of a manned       orbital   operation.
                                                                                                  "         ;:> _FUEL          STORAGE                                 +_

                                                                                    '%                SERVICE       TOWER                __    : : : •

   This    paper   is concerned       with   the special
modifications     and considerations       for Mercury                              FIGURE 4-1.--Standard                                      Atlas D launch                 complex.
launch ol)eration     involvilig   the launcli COml)lex
and the launch      vehicle.     The l)aper covers two                        supply,  service                                tower,    and the launching                                    pad.
areas, long-range         planning,    and the tests and                      All equipment                                    necessary    to check    out                                 com-
preparations       of the complex         and the launch                      pletely             each system on the complex      and in the
vehicle for the MA-6 operation.               For the sake                    launch              vehicle is located in these facilities and
of clarity, comparisons          are made between stand-                      each       of            these              systems               is completely                  validated
ard    Atlas     boosters     and    complexes     and  the                   prior  to each   launch operation.   Figure     4-2
launch     vehicle and complex          as configured   for                   shows a view of some of the checkout        equip-
Mercury.                                                                      luent located inside the blockhouse.
                                                                                 The              general   configuration     of the                                                  launch
       Description         of Launch    Complex               and             vehicle              is shown   in figure   4-3.     The                                                launch
                         Launch   Vehicle                                     vehicle             is a 1_ stage, liquid-propellant                                                    launch
   The Mercury-Atlas        6 vehicle-was     launched                        vehicle   with five engines: 2 booster   engines,    1
from   launch  ('omplex      14 at Cape     Canaveral,                        sustainer   engine, and "2 small vernier    engines.
Fla.  The launch     vehicle u_d      for this mission                        These       engines                         l)ro(tu('e            a tot a l tl,,'ust            of apllrox-
was     essentially           an    Atlas    (series)     D   and      the    imately                  360,(100                 l)ounds.                  The          fuel   tank          is lo-

                                                               _L,_CK          AND     '¢iHITE         Pi-_OTOG'RAf#,

                                                         FICHE     4-2.,--View       of equipment      in   blockhouse.

eated immediately                   above the main engines     and                           ahitude        against  range.        Two seconds after lift-
the liquid oxygen                 tank is located al>ove tile fuel                           off, the       roll lwogram         is initiated by onboard
tank, tile tanks being separated    hy a bulkhead.                                           flight equipment.    This              maneuver    is necessary
System components,    such as command      receivers,                                        because  the latmeh   pad              is oriented   so that the
telemetry   packages,  guidance   equipment,       an-                                       pitch axis of the laum'h               vehicle is 'dined on an
temms, and so forth, are ]mused in lhe two pods                                              azimuth     of 11)5° while the Mercury        spacecraft
on the sides of the fuel tank.     I,aunch-vehiele                                           insertion    head is about 75 ° . Therefore,      the roll
guidance     is provided    by a combination    of on-                                       program      has to rotate     ttle launch   vehicle    ap-
board    equipment      and raido  ground    guidance                                        proximately      30 ° to aline     it with the Mercury
equipment.                                                                                   spacecraft     insertion   heading.       At 15 seconds
   Perhaps         the best way to explain   the normal                                      after     lift-off  the roll program      is complete   and
functions        of the launch vehicle is to look at the                                     then      the pitch    program    is started.    Although
sequence of events during     powered     flight.     Such
_ sequence  is shown    in figure 4-4.       The figure                                      ALTITUDE VS SURFACE RANGE FOR LAUNCH-
shows the launch-vehicle       trajectory     plotted    as                                        VEHICLE POWERED FLIGHT PATH

                           *                    F_
                            ,                  /                                                            SUSTAtNER      ENGINE       CUTOFF       301   SEC

                                                       _I0 FT


                                                                                                                                        IDANCE       156 SEC
                   67 FT        IN.            /
                                                       -FUEL    TANK (RP-I)
                           '      STUB j             " _VERNIER     ENGINE NO.I                                                         c
                                      POD ,_                                                                                            UTOFF 130 SEC
                                                       _SUSTAINER       ENGINE

               BOOSTERENOI_                                                                             END ROLL PROGRAM 15 SEC
                                                         {2 FT 3 IN,                                             I           [               I             I               I

                                                                                                                          SURFACE       RANGE
     FzotraE    4--3.--Standard            Atlas        D launch    vehicle.
                                                                                             FI(;URE   4-4.--Sequence       of events       during   powered     flight.

                       BLOCKHOUSE        COMMAND    ABORT        SYSTEM

   RESCUE                                                                   /

 VEHICLESv              TOWER     :I    TOWER
SERVICE                                                VEHICLE         ."
 TO WER                                                    :
                                                       .::::::     /


            *%                          ,'   ,,

      Z_ WHITE ROOM                    "LwATER     AND FOAM NOZZLES

FIc, I:Rr; 4-5.--Mer(,ury        modifications      to launch      complex.

the pitch prolzranl         is active throughout       the re-
maining     portion    of l)owered       flight, tile rate at
which tile pitch l)ro/ranl           changes    the pitch at-
litude   varies    lhroughout         the trajeetm\v.        At
T4-13t)   second.s,     tile ground       guidance     station
sends :t command        which shuts off the two boost-
er engines.      Then the sustainer  engine                       is locked
ill   the   lleHtra{position and the l)oosler                       engines
;11"6jettisoned.      The sustainer   engine                        is then        FI6vRs   4-6.--Service       tower     showing       white    room.

mflo<'ke<l an<l the             vehicle    is guided     to inserlion
by lhe conlrolhthle                sttstuiner     engine    which     is
posi! ioned by commands     from the ground                             guid-
ance slali,)n.   .\t approximately    T+300                               sec-
onds, tile ground    guidance     st al ion, once satisfied
that all insert ion paralltetel'S     are attained,   sends
a command      which    shuts off lhe sustainer          and
vernier          engines.

Complex             and     Launch-Vehicle            Modifications

   .ks mentioned      previously,      in order to support
Mercury     missions,     both the complex           and the
launch    vehicle      were     nlodified.      Figure   4-5
shows the major modifications              that were made
to the (,Oml)lex.       In the service       tower, a room
was built to enclose              the spacecraft.          Figure    4-6
shows   an extermtl               view of the          service    tower
and the specially    built room.     This room, com-
monly called the "white       room," is located near
the top of the service      tower.     The spaeeeraft
is shown    in the fgure    immediately       outside     of
the sliding   doors of the white        room.      Figure
4-7 presents    a close-up    view looking       into the
white room. The figure shows the sliding             doors
in the open     position and the sl)aeeeraft                                sus-
tlended just above the adal)ter.      The figure                            also
sh(_ws tile roof in lhe folded     l)osilion,  but                           the
floor is shown   intact.  It should I)e i)ointed                             out        FIOURE   4-7.--Inside      view    of   white    room.

                                                                   spacecraft  without   external    aid or, in case the
                                                                   astronaut  l_ecamc   incapacitated,      the external
                                                                   egress crew could use tim tower to renlo".'e the
                                                                   astronaut.   Also shown in the figure is the mo-
                                                                   bile egress lower, known as tile "cherrypicker."
                                                                   Tile mobile   tower  is shown on tile left of the
                                                                   figure    in a partially extended  position.     This
                                                                   mobile    tower was used on the Mercury-Redstone
                                                                   ol>erations   ; however,        subsequent         tests on the
                                                                   Atlas    complex       indicated     that     the tower      may
                                                                   possibly     interfere       with    radio      transmissions.
                                                                   Also, the tower was sul)iect to possible                 damage
                                                                   from     the greater        pressure      environnlent        pro-
                                                                   duced by the Atlas     engines.  It was decided,
                                                                   therefl)re, that the mobile tower was not as well
                                                                   suited for an Atlas launch as was the fixed struc-
                                                                   ture previously   discussed.     The "eherrypieker"
                                                                   however    was stationed     behind  the blockhouse
                                                                   so that   it could be used as substitute         in the
                                                                   event    that     the   primary      egress   tower      failed   to
                                                                       Special      rescue and firefighting    vehicles   were
                                                                   stationed       just outside    of the complex    to trans-
                                                                    port the       egress    crew to the tower and/or         to
                                                                   meet the        astronaut    at the tower and transport
                                                                   him qway from the complex.            Figure      4-9 shows
                                                                   the position    of the_     vehicles     relative      to the
         FIGURE      4-K--Emergency      egress   tower.           launch   pad.    The astronant-transI)ort            vehicle,
                                                                   with its covering    of sl)eeial thermal        insulation,
that   the   floor    also   can   be folded      ill a manner
                                                                   can be seen in this figure.          The egress        proce-
similar  to that of tile roof. The n,)vable    doors,              (lure was pra<'t iced many times and it is interest-
floors, and roof are necessary    It)alh)w   opening               ing to note that tim astronaut           could      evacuate
of tile white r<)mn so that the _rvice     tower can
                                                                   the spa(,ecraft   and be delivered      to a safety zone
I)e moved away from the flight vehMe apl)roxi-                     outside of the e()mplex        in about o.21/o_minutes.
IHate]y 55 lnintltes  prior  to lattneh.  The en-                      A sl)eeial  firetlghting       system   was also in-
vironnlent  ill this white  roonl   was controlled
                                                                   stalled.    The four nozzles shown          ill tigure 4-5
to minimize      tile effects of humidily,       dust, and         were remotely      <'ontrolled      from the bh)ckhouse
so forth, on the spacecrafl          COml)onems.                   in such a manner       that water or fire-smothering
   An emergency         egress lower is shown         in tig-      foam could be direcled           to any area inside the
ure 4-8.    'File figure shows the egress t)latform
in the exlended        l>OSiiion such that the end of
the platform     is adjacent    to the door of the space-
craft.   When retracted,         the platform    is rotated
in the vertical       plane    about    the opposite      end
and locked in the vertical           l>osilion.  This fea-
ture is necessary          so that  the launch   vehicle,
when lamwhed,            will not strike  the l)hltform.
Actually,       the l)latform    is held ill the vertical
l)osition     during    the entire   comltdown    and, if
needed,      it is lowered    to the extended    position
in about      30 seconds    1)y nleans         of remote    con-
trol from     the t)lockhouse.     This        tower l)rovided
the aslronant         wilh    a means    of evaclmting       lhe        FIGURE4-9.--Rescue           and firefighting    vehicles.

         BLACK          AND             WHITE               Pi-,,.J l OC_AP.t"I

                                                                                                and the      spacecraft      is mounted         on   top      of    the

                                                                                                                 Pilot    Safety      Program

                                                                                                    It was recognized       at the beginning      of the
                                                                                                l)rogram     that  the launch     vehicle   would   have
                                                                                                to be modified      in some areas for Project       Mer-
                                                                                                cury;    therefore    a special  study    program    was
                                                                                                initiated      to evaluate        each system,      concept      of
                                                                                                operation,        and the effects of combinations                of
                                                                                                various      failures      that could     conceivably      occur.
                                                                                                This     program,         called   the "Pilot     Safety     Pro-
                                                                                                gram,"      drew       on the talents       of many      groups,
                                                                                                primarily        those groups         with previous       experi-
                                                                                                ence gained           from     Atlas    D operations.         The
                                                                                                philosophy         stressed     in this program      was based
                                                                                                on the use of fully developed              components       in or-
                                                                                                 der to preserve      system reliability        as established
                                                                                                 by flight experience.         The program           also estab-
                                                                                                lished a standard        for components           to be used on
                                                                                                Mercury       launch   vehicles    so that component            ac-
              FIGURE        4-10.--Firefighting                   nozzle.                       ceptability      could be based on nominal             perform-
                                                                                                ante characteristics        rather    than outstanding           or
                                                                                                better     than    expected      characteristics.          There
complex.   Figure   4-10                     shows          a close-up            view of       were some instances            in which        wiring     or cir-
one of the nozzles.                                                                             cuitr T ch,_mges were made, but in these cases
   A radio command       system was installed         in the                                    the changes        were  made     to improve     system
Mockhouse.       This system      lwovide<l    a gromM-                                         reliability.    The factor 3" rollout procedures     and
command     nleans of firing the sl)a('ecr, lft escape                                          the flight safety review for the pilot safety pro-
rockets   and aborting      the spacecraft       i)rior    to                                   grant     are discussed   in detail   in references      1
lalmch   an<l was the I)rmmry         syslenl   for abort                                       and 2.
during  the first 10 secon<ls of flight.                                                          No atteml)t   is made to mention    all changes
   The   Mercury      configuration       of the      flight                                    ma<le to the lamwh vehicle : however,    the nmjor
vehicle  is shown    in figure 4-11.        The adapter                                         changes     will be discussed.      For instance,  after
which mates the spacecraft        to the launch vehicle                                          ignil ion, the launch    vehicle is intentionally  held
is immediately                  above        the         liquid        oxygen         tank      down for several       seconds in order to detennine
                                                                                                lhat the engines     are functioning       properly.    This
                       MA-6             FLIGHT             VEHICLE
                                                                                                change     was a result       of previous       experience
                            16 FT II IN.                 ESCAPE        TOWER                    which showed       that,   after   ignition,    the engine
                         _£_L._ ... _ _SPACECRAFT                                               l>erformance     could      possitdy      become     erratic
                    3= 6 TOIN.
         4 FT 3 IN,    - _F ...... (@SPACECRAFT                                  ADAPTER         (rough   combustion)       and cause destruction           of
                                                                                                the launch vehicle.       The experience       also showed
                                                                                                that the additional      hold-down       time would pro-
    i                                         --=I°FT                                           vide sufficient time to detect such a malfunction
 95FT    4 IN.                    TANK_                    BULKHEAD                             and   shut   off the engines        before   lift-off_     thereby
                                         t       /
                 67 FT4         IN.          I/--"                                              preventing  destruction.
    ]                       /     STUB_              /    -FUEL TANK (RP-,)                        Another  system that was modified   is the com-
                                                         -VERNIER   ENGINE              NO. I
                                                                                                mand destruct    system. This system was changed
                                             "       -       USTAINER            ENGINE         to include    a time delay         circuit so that if a man-
                                16 FT                                                           u'd (leslruct     command           was sent to the launch
                                                                                                vehicle,     receil)l  of the command                would          im-
PIOURE    4--1l.--Mercury               configuration             of    flight     rehi<rle.    mediately      fire the sl)a('e<'r'lft escal)e       rocket        too-

tor: but destructactionof the launchvehicle                           mand from ground       control,  the control unit calls
                       3         to
wouldbedelayed seconds allowthespace-                                 for spacecraft   abort.     It should be pointed     out
craft tittle to escal)e front tim humch vehicle.                      that  just prior   {o launch,    the ASIS    indicates
    The addition     of the time delay circuit      intro-            to the blo&house     that the system is in a ready
duced the major modification         made to the launch               condition;      however,        the system    is not actuaJly
vehicle--the     abort sensing    implementation       sys-           activated      until the       launch   vehicle   has risen :2
tem (ASIS).          This system     va_ designed      spe-           inches.    This feature precludes         spacecraft    abort
cifically    for Project   Mercury,     and its purpose               in the event that _he engines should shut down
was to provide      an automatic     system that would                after   ignition    but prior     to launch-vehicle        re-
sense specific quantities       in the launch     vehicle,            lease.   ()f court,    the ASIS      is far more compli-
detect when those quantities         indicated   impend-              cated than implied        by this discussion,        however
ing catastrophe      in the launch vehicle, and abort                 the intent of this paper         is to pl_sent       the gen-
the spacecraft     to escape the catastrophe.              It was     eral explanation      of operation     rather than details
helieved    that the ASIS          was necessary         because      of the system.
some previous       flights of the Atlas D had indi-
                                                                                Systems          Preparation     for     MA--6
cated that the time period between               an indication
of impending         catastrophe       and launch         vehicle        All of the pl_evious discussion has dealt with
destruction       could      be    extremely         short--ap-       long-range   planning  and implementation     in re-
l)roaching     the reaction      time of a human            being.    gards   to the complex    and the launch    vehicle
It was decided      therefore      that an automatic           sys-
                                                                      for the Mercm2¢ program.           The following        dis-
tem would       be desirable,      at least until more ex-
                                                                      cu_sion will concern       the actual    preparation      of
perience was gained on manned                flights.
                                                                      these systems      for the launch     of MA-6.        Upon
  Basically,         the ASIS     consists     of     _nsing   ele-   arrival    at Cape Canaveral,      the launch       vehicle
ments which           detect malfunctions           and a control
                                                                      was inspected      and prepared    for erection      in ap-
unit that receives the signal         and initiates       the         proximately      48 hours.    The launch      vehicle wa.s
proper    action.   The sensors u_d in this system                    transported      to the complex        on a dolly-tylre
are rate gyros, pressure      switches,     and electrical            vehi(.le.    The launcher     on the launch       pad was
power     sensops.   The control       unit is basically              rotated     about 90°; and the launch         vehicle was
connected     to two systems,    the sp:wecraft       escape          backed       into the. launcher, alined,           and   attached
system, and the booster-engine          system.     For ex-           to the       launcher.    A hoist cable            was   then at-
ample, if the control unit receives a signal from                     tached       to the   from      end   of the     doily   (top   end
a sensor, the unit tells the spacecraft         escape sys-
                                                                      of the launch vehicle)   and the dolly and launch
tem to abort the spacecraft;         then the unit tells
                                                                      vehicle were hoisted to the vertical    position,     the
the booster engines     to shut down.          Also, if the           launcher    rotating back to its original     position.
engines     are     intentionally     shut    down      by a corn-    Figure    4-12 shows the launch       vehicle     being
                                                                      erected,  and figure 4-13 shows the launch          vehi-
                                                                      cle after      erection      in launch    position.
                                                                         After        erection       it was     learned        that   the
                                                                      launcher      mechanism,     in which     the launch    ve-
                                                                      hicle was mounted,         couhl not be adjusted      suf-
                                                                      ficiently    to aline the laun,'h      vehicle properly.
                                                                      Therefore,      the launch    vehicle was taken down,
                                                                      the launcher       mechanism     was replaced,    and the
                                                                      launch     vehicle    was reerecled.     All systems     on
                                                                      the complex        and the launch     vehicle   were then
                                                                      tested       individually.        For   examt)le , complete
                                                                      tanking       tests were      conducted   in which the fuel
                                                                      and liquid oxygen      tanks were loaded .rod pres-
                                                                      surized   to flight   pressure.       This    test is per-
                                                                      formed    to determine      if any leaks are in the
                                                                      systems   and also to <,beck out the controls           re-
      FIGURE      4-12.--Launch     vehicle   being    erected.       late(l to each system,        l)uring    this test on the

                                                                      After   electrical      mating,      the launch     vehicle
                                                                  and spacecraft         participate       jointly in ull tests.
                                                                  These tests are discussed             in paper    5 on spuee-
                                                                  ('raft 1)rel)aration.        The first attempt      to launch
                                                                  MA-6      was on ,Ianuary           ")7, 1962.   The launch
                                                                  vehMe      was loaded         with fuel on January            24.
                                                                  However,      the mission         was canceled     because of
                                                                  ex<ressive cloud        cover     in the launch      area and
                                                                  was rescheduled       for February       1; so the fuel
                                                                  tank was drained.       On Jammry      30, the fuel tank
                                                                  was again loaded;        however,   normal     inspection
                                                                  procedures   disclosed     that the insulation-retain-
                                                                  ing bulkhead    in the fuel                              tanks    was leaking.
                                                                  Figure  4-14 shows a sketch                               of this bulkhead.

                                                                                                                 f-LOX          TANK


                                                                   FUEL TANK_
                                                                     BULKHEAD--                   __             _-LOWER               RETAINER

    PmwaE               a
                                                                                                                 _-FUEL-TANK                   APEX
MA-6 launchvehicleno majorleakswereevi-
dent; however,someminor leakswere dis-                            Fmum:         4-14.--Bulkhead                  between        fuel     and    liquid
coveredndsubsequently  corrected.                                                                  oxygen        tanks.
  The autopilotsystem,asanother example,   is
alsotested;however, beforeautol)ilottestsare                          This partition      is actually    made up of three
           on                      t
conducted the launch COml)lexhe gyro                              sel)am_te pieves.        The top line represents         the
packages             in
         arecalibrated a laboratoryatCape                         main Imlkhead         that provides      structural  integ-
Canaveral with speci'tl testing equil)ment.                       rity.    Below this bulkhead         is 11/_ inches of in-
These         arealso rically mated
      1)ackages      elect             tothe                      sulating    material     and the lower line is the re-
abort-sensingcontrolpackage whichis part of                       taining     bulkhe'ld     whose     only     purpose  is to
the ASIS         previously   discu._sed.     During      these   supl)ort  the insulation.   The leak                                  was in the
                                                                  lower retainer  and this had allowed                                  fuel to soak
laboratory        and systems      tests, various     anoma-
lies were       uncovered    in the gyro package            and    into   the      insulation           and       become         trapped.        This
the ASIS          control   package.      These    lrt('kages     trapped         fuel,        the amount   of which   was un-
were replaced       and systems tests were completed              known         at the        time, could possibly have caused
satisfactorily       on     the   launch     vehicle.     All     excessive    inertia             loads        to be applied    to the very
launch-vehicle       systems    were then tested sinml-           thin   retainer.                After          a careful    study    of the
taneously      in a test ('ommonly         known      as the      po._sible effects connected      with this problem,        it
launch-vehMe         flight acceptance     composite     test     was decided    that sufficient flight experience       had
 (FACT).         This test is conducted      to determine         been obtained     on previous    launch vehicles     with-
that all launch-vehicle         systems   are COml)atible         out the retainer      to justify     removing     the re-
so th,tt each system will not adversely           affect the      tainer from this launch vehicle.         Therefore,     the
operation        of    another.     The    htmwh-vehMe            sustainer engine                 was removed,                 the lower apex
FACT must be successfully            acCOmlflished    before      of ihe fuel tank                  was removed                  and a scaffold

the sI)acecra     ft is elect ri('ally   mated   to the launch     was built         inside       of the launch vehicle up to the
vehicle.                                                           retainer.          After        the retainer was removed   _tnd

          w                a
all systems erereconnected, complete   test                                                         The other problem      concerned     the pumping     sys-
programwasrerunon everysystem    disturbed                                                          tem that loads liquid oxygen aboard          the launch
                                flight test
by the modification.The simulated                                                                   vehMe.     This prot)lem     occurred    during   liquid
WaS rerlln  on February   16, 19(;'2, and the launch                                                oxygen   lanking  at 'I'-'22    minutes.     The outlet
vehicle was again loaded with fuel in prepara-                                                      valve in the main liquid        oxygen     pump     failed
tion for launch on February    20.                                                                  in the closed pc,silion,    but .t smaller    secondary
                                                                                                    pump was switched       into the circuit    to complete
                                    Countdown                                                       the tanking  operation     with no further     incidents.
                                                                                                    The remaining    part of the countdown     was per-
   During      the actual     launch     countdown,        two
                                                                                                    formed  smoothly     and without   trouble   of any
problems        were    experienced---one         with      the
                                                                                                    kind.        At         lift-off,        blockhou_                   equipment               indi-
launch     vehicle   and one with ground            support
equipment      on the complex.         The fi_:_t problem,                                          rated      that         all    systems            were            functioning               prop-
the one involving        a launch-vehicle       system,     oc-                                     erly,    and about                5 minutes              later,       the report            from
curred    at T-120      minutes     and involved       ,'t mal-                                     the     Mercury               Control            Center            of successful                  in-
function of the guidance  rate                           beacon.     The bea-                       sert ion proved                   that    the launch                 vehicle          had     per-
con was replaced  and checked                            out satisfactorily.                        formed           it s job nea rly to perfection.


1. Program         Office,         Mercury/Atlas           Launch         Vehicle:       MercuryAtlas                Launch            Vehicle       Factory             Rollout         Inspection
      General       Procedures               and   Organization_--Pilot              Safety       Program       of    the     Atlas       Launch           Vehicle        for      NASA      Project
      Mercury.           Rep.         no.     TOR-594fl101)RP_3                  (Contract          no.     AFO4(647)-930),                      Aerospace             Corp.,       E1     Segundo,
      Calif.      Oct.      31,    1961.
2. Program        Office,         Mercury/Atlas           L_mneh      Vehicle:         Mcrenry/Atla.s            Lau_wh           Vehicle         Flight        Safety          Review       General
      Operating          Procedures             and   Orga_ization_Pilot                 Safety      Program          of     Atla.s      LatlJtell         VeIticle      for     NASA        Project
     Mercury.            Rep.       no.     TAR-594     (1101)RP-4           {Contract        no.    AFO4      (647)-930),              Aerospace            Corp.,      E1 Segundo,            Calif.,
      Oct.     31, 1961.

                5.        SPACECRAFT                     PREPARATION                     AND     CHECKOUT

By G. MERRITT             PRESTON,     Chie/, Preflight  Operations    Division, NASA Manned Spacecra#                            Center;      and
                J.   J.    WILLIAMS,     Preflight Operations   Division, NASA Manned Spacecra#   Center

                               Summary                                   this t,ype of program.       The flight, tests also con-
                                                                         tributed   to this design evaluation.
    Friendship     7 arrive<l at           ('ape ('anaveral      on          The detailed    examination     of the spacecraft
August      27, 1:)61, and was             launched    February
                                                                         design,  therefore,          was     primarily         conductexl          at
2t), 1982.     The spacecraft              underwent     detailed
                                                                         Cape Canaveral.
system-by-system         tests after   arrival     to verify                This examination           involved           functional      testing
its   confignration.           The   configuration       was             of the spacecraft         systems,    observing       in detail
ehan_ed    as resul! of information         obtained   from              the performance          of the systems.          These    tests
tile MA-5        orbital     fti_ht.  After     the design
                                                                         were repeated       often and duplicated            as near as
changes   were iucorporated,       the spacecraft                 un-    possible     different       flight    environments         and
derwent   final ha,tlbrar systems tests.                                 modes.     During       these tests, ,lZ discrepancies,
   Y.t the launch      (.onq)lex tile spacecraft                 was     no matter       how trivial,        were    _rutinized       for
mated to its launch       vehMe and combined                    tests
                                                                         their significance.        I)esign changes       indicated    by
were   conducte<l          It) ascertain     tile   c<)ml>atibility      the_ tests and the flibrl_t, tests were incorporated
of the sl)acecraft,         latmch  vehicle, and SUl)l)ort-              its rapidly      as possible so that    the optinmnl
ingran_ei|lstrtln+enlation.             After ascertaining
                                                                         sl)acecraft    configuration  was flown.
the cOral)at ibilfi y and ftmct tonal capal)ilit        ies of               Astronauts     Glenn and Carl)enter   participated
all elements,      tilt, space vehicle was successfully
                                                                         in all system      checkouts    at Cape Canaveral        and
launched      February        20lb.                                      reviewed    all    design    changes.      This participa-
                                                                         tion      for intimate     familiarization     with
                                                                         the   spacecraft      and     a better           understanding             of
   Friendship    Seven arrived    at Cape C+maveral,                     its   system.
Fla., on August     27, 1961, for final preparation                                            Time         Utilization
for flight.   It w'ts in checkout     at Cape Canav-
eral for 166 working      days.    This appears   to be                     By examinin_z        the expenditure        of the 166
a long time; therefore,      the philo_I)hy     of oper-                 clays that Friendship        Seven spent at Cape Ca-
ations   for Project    Mercury    tlnLt dictates    such                naveral,   the effort spent in testing       and modify-
a lengthy      checkout     at+ Cape      CaJnaveral     is              ing the spacecraft        can be seen.     The checkout
d iseus+d.                                                               of the spacecraft    itself was conducted       in Hangar
   The reliability             of the Mercury    project,   was          S con|l)ound      at ('ape    ('anaveral,   Florida,    and
established     by         a    step-by-step  developmental              htsted approximately         133 days as shown       in fig-
flight program    and a repeated    detailed ex_mi-                      ure 5-1.    This checkout       was followed     by launch
nation of the spacecraft    and its systems.                             comi)lex   operations     in which the launch vehicle
    Because  of the urgency    of the program,    all                    and sl)acecraft    were mated and testin_z was con-
                                                                         ducted   to assure     that   the launch  vehicle and
spacecraft    produced     were umd for flight               testing
and none     were a,vailal)le  for developmental                 test-   spacecra.ft    were mecha.nically,                 electrically,      _ld
ing in the laboratories    until late in the program.                    radio-frequency       compatible.                 This testin_        was
Therefore,   the preflight      operations   conducted                   followed     by final preparations                and as_mbly          for
:_t, C_q)e Canaveral    on the various      spacecraft,                  the launch.
served not only to prepare     that particular     craft                    The    time spent in the hangar   can be initially
for flight,  but, it qlso was part of the design                         broken     into two parts :
evaluation   of the spacecraft     that is typical      of                  (1)    Work    was performed    on the spacecraft

                                                           "WORK      63
                                                                                                                                                                  EI/_C_RICAL     &
                                                                                                                      ASS_BLY          33
                                                                                                                                                             F    SEQUENTIAL               II
                                                                                                                      DESIGN     CHANGES
                                                                                                                                                       30 --]--ENVIRONMENTAL                 7

                                                                                                                                                                  CO{_#JNICATIONS                5
                         -HANGAR    CHECKS      153--                                                                                                            _E LECTRI CAL     &
                                                                                                                     _ELECTRICAL          &
                                                                                                                      ELECTRONICS                  i_--I          SEQUENTIAL                     3

                                                                                                                                                                 [i NSI_UMENTATI        ON           2
                                                                                                                                                                   STABILIZATION             3

                                                                                         -TESTING            41 --
                                                                                                                                                                  MECHAN   ICAL        i
                                                                                                                     -MECHANICAL          22 --

TOTAL   166
                                                           _SYSTEMS         70 --
                                                                                                                     -SIMULA_:D        FLIGHT

                                                                                                                     --ELECTRICAL         &
                                                                                             REWORK        o9_--     I ELECTRONICS
                                                                                                                     '-_C: _ICAL              22

                                                                STING       13

                         COMPLEX     CHECKS         33--        UNCH-VEHICLE

          Time Analysis   of Friendship        7_s         IMODIFICATION              13
          Preflight  Operations                            L_ATHER          7

                           I_GU_E      5-1.--Time          analysis        of    preflight            operations        on   Friendship                 7.

such    as assembly     and     servicing            the   sl)aceeraft                        sl)ent   in a(ldinz    instrumentation;       and 9 were
and incorporating       desizn ehanges      that had been                                     spent mo(lifyin_      the reaction    control   system.
dictated    by previous      flights.   This work took                                            Of the 70 days spent         in lesling    and taking
approxinmtely      63 of the 133 days spent in the                                            corrective    a('tion, 41 were used for actual test-
hangar.                                                                                       ing.          Of      these       41 days,                 13 were           used        by            the
    (9) Systems     testing, troul}les]moting,     'm(1 re-                                   elect rical and eleel ronic systems,  29 for the me-
placing of conlponents         as the result of this test-                                    ('hani('al  systems,  and _; for overall   simulated
ing were also ('on(hwte(l       in the han_rar.   Seventy                                     flight        tests.  Figure     5-1 shows a further   break-
clays were spent in this phase of the ol)eration.                                             down           of the electrical     'rod electronic systems
The launch-comlflex        operat ions required    33 days                                    tests      and the meeh'mieal                            systems        tests.
to perform.
                                                                                                Twenty-nine                  days were sl)ent troubleshoot                                           ing
    A further   breakdown        of the aforementioned
                                                                                              and  replacing                  components     as the    result                                          of
categories     would show that 33 days were spent
                                                                                              troubles             eneomttered                during             these     test pericMs.
during     the work periods     to assemble      ttnd serv-
                                                                                              Of these 29 clays, 7 days were spent on the elee-
ice the spaceeraft    in the han_zar.         Thirty   days
                                                                                              trie'fl an(l ele('troni(_ systems and '22 days were
were spent ineorpol'atinfz      (lesiTn chang'es as the
                                                                                              spent        on the me(.hanical                          system.           A nlajority                     of
result of the previous     flight.     ()f lhese 30 days_
 11 were sl)ent ehanR'ing the wirino- of the elee-                                            the      troubles          with         the mechanical                       system            were
triea] and sequential    system;     7 were spent modi-                                       associated             with       the       enviromnental                    control               sys-
fying the enviromnental        control    system ; 3 were                                     tem which              took 15 days                  to correct.

  Of the 3adaysspentonthe launchpad (ac-
tually, 43daysweresl)entonthepad,however,
 10of the_ were spent I roublesh(_)ting and have
been        included               in the              above        analysis),              13 days
were spent in pad testin_z : 13 days were required
1o modify    the launch    vehicle    as a result of a
malfunction     of the fueling     system,   and there
 were 7 days of weather   delays.                                                                            VALUES

                  Spacecraft                          Design         Changes

   Friendshi    l> 7 had several design changes nmde
at Cape ('anaveral        as a result of informatioll
obtained     from the orbital    flight of spacecraft  9.                                                lelaURE 5-3.--IIeat          sinks added to roll thruster          as-
A total of 255 changes        were made in the space-                                                             semblies     ill     rea('ti(m control system.
craft   while at flw ('ape.        Some <)f these items
will be discussed                          subsequently                   for    each         of the
major spaeecrafl                          systems.
                                                                                                         Louis, Mo., and data obtained       from the space-
                                                                                                         craft 9 flight indicated   a need for removing      the
                            Reaction                  Control      System                                excess heat generated     by the lhrusters.       This
                                                                                                         heat resulted  in undesirable    fuel temperatures.
   The       following     changes                               were     made         to the      re-
action       control   system:                                                                                                 Electrical      System

   ( 1 ) Plastic    flare seals were removed    from the
amomatic       system     inlet and outlet   cmmections                                                     The following            changes   were       made   to the elec-
to the thrust       ('haml>er solenoid   valves and re-                                                  trical system :
placed    with soft qlumimm_        washers    (fig. 5-2).                                                   (1) The fuses were relnoved    from the stand-
"l'es_s conducted     at Cal>e ('anaveral        and Mc-                                                 by inverter    circuit  for the lnanual      nlode     of
 l)(mnell    Aircraft   Corp.,    St. L<mis, Mo., re-                                                    oi)erat ion.
vealed that the plastic      seals resulted    in relaxed                                                    (12) The fuse h<)lders were structurally       rein-
tor(tue on lhe tube fit[in_s 'it ambient         teml)era-                                               forced because of the record of mechanical         fail-
lures.     It was also shown       that   this condition                                                 ures that they        have experienced  in the past.
was      further                aggrav'tled                     t)y the     high           tempera-          (3) In(tieator     lights were added to enable the
tures   found                     in            the      vicinity           of     the        thrust     pilot to determine           which    inverter      was powering
chambers.                                                                                                the bus.
    (2) IIeat sinks were added        to l)oth manual                                                      (4) An auxiliary               battery    was     added   to the
and    automatic   roll thruster     assemblies      (fig.                                               maximum-altitude               sensor    wiring      to eliminate
5-3).     Tests a! McI)omml]     Air(.raft    Cort). , St.                                               vohage transients   in the circuits.
                                                                                                            (5) The abort sigmal to the sen_)r                    was inter-
                                                                                                         locked  with a spacecraft     _paration                   signal    to
                                                                                                         prevent   the tower     from    jettisoning                  prema-
                                                                                                             (6) A camera  programing   system was added
                                                                                                         to enable the c.uneras   to run at high and low
                                                                                                         speeds so that the film w(mld last throughout
                                                                                                         t he mission.
                                                                                                             (7) Wiring      t<) the thruster      solenoids      was
                                                                                 FLARE SEAL              In'ought   through     a common      connector      _ that
                                                                                                         the solenoi<ts    could I)e disabled     for long dura-
                                                                                                         tion autopilot      checkout   to prevent        electrical

   FIOUB,     E   7v--').   -    I¢.ca('lioll           Control      System        flare      seals.     overheating      of the        solenoids       during   testing.

                 Environmental                     Control          System

   The following     changes    were                                  made       to the        en-
viromnental    control   system:
    (1) Advanced     water-type       heat  exchangers
(cold plates)    were installed     under the 15(t and
250 main inverters    (fig. 5-4)•       The results    ob-
tained  on the spacecraft       9 flight indicated      in-
sufficient       cooling.

                                                                                                     FIGURE   5-ft.--Debris           flmud      in     cooling       fatt     (_f    Space-
                                                                                                                              craft    9 after        flight.

                                                                                                        (3)   The      Muminmn               check      valves        in the freon-
                                                                                                     water  inverter   cooling  system      were replaced
                                                                                                     with stainless  steel valves.     This change      was
                                                                                                     made   when it wn_ found       that    the aluminum
                                                                      PORT (OPPOSITE                 check valves tended to corrode      'rod remained    in
                                                                          SIDE)                      eitller the oi)en or closed position.
                                                                                                         (4) An indicator     was installed    on the instru-
               FIGUItE       5-4.--Inverter                 reeling        [)hlle.
                                                                                                     ment panel to provide      the astronaut,     with an in-
                                                                                                     dication   of heat exchanger    exhaust     temperatm_
                                                                                                     in order to control     the cooling    flow in the suit

                                                                                                         Automatic        Stabilization           and       Control          System

                                                                                                        The following        changes    were made     to the
                                                                                                     automatic   stabilization     and control  system:
                                                                                                        (1) The autopilot       w'ls replaced  with a later
                                                                                                     model     which   contained       new logic       circuitry.
                                                                                                     This _'ir<'uitry  prevented      erroneous    orbit pulses
                                                    - ORIGINAL        SCREEN                         due to intermittent          _ctor     switching.        This
                                                      W;TH    25"     Oi_ POLES
                         -NEW     SCREEN                                                             change    was designed      to conserve     reaction      con-
                          WITH     .06"     DIA    HOLES
                                                                                                     trol system fuel.
                                                                                                         (2) Fu_s     were added to the power leads to
FmURE        5-5.--Cooling            fan         ¢hwt     inlet      screens        for   Friend-
                                                                                                     the rate gyros to prevent         loss of an inverter        in
                         ship      7 lind         Slrtcl,('raf!        _._.
                                                                                                     tim event of '_ malfunction         in the gyro.
                                                                                                         (3) Heater blankets       were added to the ._an-
   (9) The cooling         fan duct inlet screens were
                                                                                                     hers.   It was found that the effectiveness            of the
changed      to sel_ens     having     0.0(;-inch     diameter
                                                                                                     s('amwrs  was re(lu('ed unless                       the scamper                bolonl-
holes.     (See    figure    5-5.)      This     change     was
                                                                                                     eter was maintained    at 75 _.
required      when     the    postflight       inspection      of
spacecraft     9 revealed      that    the cabin fan was
                                                                                                                         Instrumentation                 System
jammed     by small bits of metal, fabric, and rub-
ber, shown    in figure 5-6, whMi were ingested                                                          The following     changes    were                      made          to the      in-
into the fan under      zero-g  conditions    through                                                strnmentation     system :
the 0.:25-inch diameter   holes in the inverter    cool-                                                 (1) An instrmnent         package                          w:ts       oh.raged
ing duct        screens.                                                                             from     a      position         near       the        right        foot.          This

                                                                                                                                        OF_iGINAL                 I_AGE

                                                                                                                     BLACK            AND        WHITE                PHOTOGRAPH
        change    was made to avoid       interference with
        the pilot& right, foot during  flight and to facili-
        tate removal   of the hatch for egress.
           (2) Temperature       pickups were added to the
        1-pound    automatic    and manual   roll thrusters
        to monitor     the effectiveness  of the new heat
           (3) A manual                 blood        pressure      measuring            sys-
        tem was installed.

                                  Miscellaneous         Changes

              'two      other     design      changes          were made.          They
        are    :

           (1) A person'd       equipment       container      was
        mamffa(_tul'ed    and installed    to provide     a place
        for storing    the items which the astromtut          took                             ]_'IGI:RE   5-7,--Slm(,ecraft              (.aided       for     ele(.trical             i)ower
                                                                                                                                 system      tests.
        on the flight to perform       the activities   required
        of him.
                                                                                               I)ower       surges        occurred,            the        invorter                was       re-
              ('2)     Remowtble           filters      were      installed       on    the
                                                                                               placed.     Previous                 experience                 has    indicated
        pilot's   observation window   to provide   protec-                                    that such inverters                   often   fail             COml)letely    :It a
        tion to the astronaut     when expo_d     to direct                                    later date.
                                                                                                   The instrmnentati<)n                     system   was thoroughly
                                                                                               tested 'm<l calibrated                     on the I)en<'h as shown in
                            Hangar          S Systems             Tests
                                                                                               figure 5-S ;it Cape Canaveral        l)rior lo its instal-
            Checkout     operations     at Itanffar  S consisted                               lation in the sl)acecl'aft.      The s.vstem was tested
        of individual      systems tests followed     by a simu-                               again after      it ha<l been installed     in the st>ace-
        lated flight test with ,ill systems operating         in a                             craft.   The l>rimary       lmrpose    of the latter   test
        mamwr      apl)roa<qling    flight conditons    as nearly                              is f<mrfohl:      (l) to determiJ)e    the error, if any,
        as possible.               The following    system                tests        were    between lhe hat(lithe        sig]ml normally      used to
                                                                                               transmit     data to the blockhouse        or olher    test
        performed               on Friendship    7:
                                                                                               equilmmnt      in the hangar       and the sio'na] radi-
              (1)      Electrical    power
                                                                                               ated through      the transmitter:     (_) to determine
              (2)      Instrumentation
                                                                                               l>ossil)Ie system     interference     with the system
              (3)      Sequenti'd
                                                                                               oper,ttino'  in the sl>acecr:tft : (3) to make a sin-
              (4)      Environmental          control
              (5)      Communications
              (6)      Reaction     control                                                         tt                                        I
              (7)      Communications            radiation     tower test.
              (8)      Automatic       stabilization       and control
              (9)      Altitude     chamber       tests

            The electricql    power    systenl test was the ini-
        tial test perfcwmed       on the spacecraft.       The test
        determined      if power could be safely applied            to
        the control      and power       distribution    system     of
        the spacecraft.        The test also checked       automa-
        tic and mamml        a-c inverter     switching.     Figure
        5-7 shows the spacecraft          cabled up for this test.
        Similar    cabling    is used in many of the follow-
        ing tests.
           ])ower surges on the d-c bus were experienced
         when the 15_) v-am t) ma b_ h_rerter  was switched                                    FIGURE      5-K--Ben('h             setul)    for      testing        S1)llce('F0.ft         ill-
        on the line.    Because   an excessive   nmnber     of                                                                 strumentation.


BLACK   AND          7.'hivf!       PH_TC(I_,,a,P.t4
gle-point alibration      of
                     check thecompleteali-     c                                  leakage    was redu('e<l to within        the specification
bration madeon the bench;and (4) to insure                                        v<flume by employing           a speciti<' procedure        in
thatthesystem wassatisfaeto_"   tosuplmrtother                                    opening     tlle valve.     The repeatability         of this
spacecraftests. No majorsystem         discrepan-                                 1)roeedure      was validated;       that is, the leakage
cieswereuncovered uring this testing.                                             rate remained      wit bin sl)ecificat ions after f<)llow-
  The sequential systemtest providesfor the                                       ing the opening   procedure.
checkout f the automatic  andmanualsequen-                                            (2) The <)xygetl-flow-sensor    warning      light
tial system.Thesequential  system     testingmqy                                  failed 1o come on when the l)rimary      bottle was
he broken down into four maj<)r pha_s:                                            exhausted.     The .sensors    have shown     erratic
namely, (1) launch sequence, orbit se-                                            l)erforman<'e   in the I)ast.       It was de('ided     that
quence,(2,) escape abort sequenee_             and                                th(_ grouml   aml fli_zht monitoring         was adequate
 (4) tvcovery   sequence.    ('ontrol      signals                                information     to warn         the    pilot   of oxy_zen
were      fed       to       the      various           inlluts      of     the   quantity.
sequential       system      and the outl)ut           functions                      (3) The    hi_h-l)ressure         oxygen     regulator
of the system were monitored.                 The maximum-                        showed an external        leak.     The valve body was
altitude     sensor actuates        tile jettisoning        of the                foutnl t<>be defect ire.            The defect was repaired
escape     towel'.     Although        it is called      a maxi-                  stol)|)ing    the external       leak.
mum-altitude        sensor, it is really a variable          timer                    (4) The tduminum               freon    check wdve stuck
whos_ time delay depends on the existence                    of an                ol)en.     These valves were replaced               with newly
abort signal and the time from lift-off that the                                  designed        stainless      steel    check    valves   whi(.h
abort signal occurred.             During     the abort ph'tse                    ol)erate(l    properly.
in the simulated         flight of Friendship           7, it was                    The l)rimary          purl)ose     of the communication
determined       that this sensor actuated          early.     The                system      tests was t<) determine              the electrical
sensor     was replaced         and tile abort        runs were                   characteristics         of the individual           compm_ents
repeated     successfully.                                                        that, comI>rise the onboard              communications      sys-
    The environmental             cotHrol     system       (ECS)                  tem.   Ahhough       the test equipment      was phys-
('heekout     conducted      1)rior t<>the altihlde-cham-                         ically h/cate(l  approxinmtely       100 fe_t awqy in
I)er test determined         the functional        operation     of               the checkout    trailer    (fig. 5-10),  the test was
the individual        comt)onents        of the ECS system.
The oxy_zen bottles            are serviced       to operating
pressure      at this time for the altitude-chamber
  ,ks the result of testing,  the following   major
ECS discrel)an<'ies   were uncovere(1 :
   (1) Excessive    leakage  of the high-pre_ure
oxygen shutoff  valve was tinted.   The slem was
removed  from the valve body and the lubricant
was foun(|   to hare  hardened    on the O rings
and se'fling   surfaces (fig. 5-!)).     The O rings
and 1)acku]> seals were replaced,       and the com-
ponent was lubricated    and rel)laced     in the valve
body.    The valve e<lnlimled    to show a leakage
caused   by the seals not seating    l)roperly.     The

                                                )-RING SEAL

                                   BACK-UP      RING

F16(:RE   5-9.--IIigh-l)ressure           shutoff       oxygen     valve   stem   FIGURE   5   lt).   CoIllllllll|i(':ttioIls       system   test   eqlliItllH'tlt
                sh(>wn      with    hardened        lubricant.                                             in   checkmlt        trailer.

equivalent     to a bench test. with tile components
 in the spacecraft.       The test revealed     the fol-
 lowing    discrepancies   :
    During     IIF rescue voice receiver    cheeks, the
 IIF output      change  was 14 decibels   with an in-
put signal level change        from 5 to 50,000 micro-
volts.      Tlm specification     requirement      was for
not more than 10 decibels.          With an input vari-
ation of from       10 to 50 microvolts,        the output
change      was 7 decibels.       This deviation      from
specification    was not considered       serious and was
considered     acceptable.    It is well to point out at
this time that detailed       sl)ecifications       have been
estahlished     for the perfornrtnce          of spacecraft
equipment.       However,   during       spacecraft     check-
out, when the performance            does not meet these
specifications,    the required       performance        is re-
viewed by considering      the requirements        for the _
particular    flight and the increase      in knowledge
about     the performance     requirements      that   has
been obtained   since they were originally      estab-
lished.   Thus,    equipment   is not    arbitrarily
changed   when it does not meet spet, iiication.                                                FIGURE            7_12.--Sp'l(.e(,raft                       being     installed             on    ('ommu-

                                                                                                  ]li('_ltfolig               t<*wer      for   (*oitinHlllic,qtioll               flnIfxIlll_l,   tents.
   The reaction     control  systenl   (RCS)     checkout
procedure    determined     the condition     and opera-                                       system    gas integrity.        The system         was then
tion of the RCS system.          Tests were conducted                                          filled   with     35-1)ercent      hydrogen         l)eroxide
in a special    test ('ell (fig. 5-11).      Several    gas                                     (II_O_) for 24 hours to monitor            decomposition
checks were employed         to determine     the overall                                      pressure    rise and to determine          system     cleanli-
                                                                                               ness as well as to l)recondition           the system       for
                                                                                               use with 90-1)ercent       II:O.,.    Following        the 35-
                                                                                               percent. H:()._, surveillance,      a hydrostatic        check
                                                                                               of each     system     using     35-percent      If:O:     was
                                                                                                nmde to determine     system liquid   integrity.     A
                                                                                                24-hour  surveillance     using  90-1)ercent     II_oO2
                                                                                                was then   conducted.       This surveillance      was
                                                                                                followed     by a functional                                    check that pressurized
                                                                                                the    system     and    static                                   firing  each   of the
                                                                                                   The system 1)erformed          very well during      these
                                                                                                tests, except       the mamml      proportional       control
                                                                                                mode ha(t slightly         higher   stick forces than de-
                                                                                                sired.      These forces, however_        were acceptable
                                                                                                to Astron'ults       Glenn and Carl)enter.
                                                                                                    Communications         system    tests were made on
                                                                                                the radiation       tower to determine       the IIF char-
                                                                                                acteristics     ()f the I)icone antenna.        Tests of the
                                                                                                other comlnunieations   system COml)onents    were
                                                                                                al_ made at the same time to permit        the At-
                                                                                                lantic Missile    Range to ewduate   the system.
                                                                                                For this _est the Sl>:wecraft  was 1)laced on a.
                                                                                                44-foot-high                        wooden tower as shown  in figure
 FIGURE   Y_-ll.--Sp,l(,ecrnft                    in   reaction          control   system
          facility             for   functi,nal         test      of   system.
                                                                                                5-12,     The                     test is conducted with no ground

          634401     O-62-'_

                                                                                                                          •    " t:,

                                                                                            k_LACK        '_f_:)               WHITE              PHOTOI_RAP_
FmURE o-13.--Dynandc           tests of antoi)ilot         in dynami(.

servicing     equipment      ((ISE)    cables connected    to
the spa('e('r,tft;      thus    the flight   configuration
was simulated       as closely as possible.
   During      the test it was noted tllal the auxiliat T
[TIIF     1)eacon caused some interference            on the             FIGURE 5-14.--Autom'tli('      ('he(.kmlt equil)lneIl[                                         for
UIIF      voice transmission.         Since the interfer-                             (.he('king h_gi(' of antopih)t.
ence was not great          and (lid not affect tile intel-
                                                                         l)roximately  125,t)()0 feet                         and       a simulated                    mis-
ligibility     of UIIF      voice transmissions,            system
                                                                         sion was conducted.
ot)eration      was considered       satisfact(_l'y     for flight.
    'rile .tutomatie     stabilization        and control       sys-        Test dat.t   indicated     that the 15(t v-am 1) in-
tem (ASCS)           ('heekout      of tile sl)aeecraft         was      verter  overheated      during    the first three    runs.
                                                                         The flow uriti(.es were inere,tsed        in size for the
divide(l      into two parts:          a static      test and a
                                                                         fourth  run.
dynamic       test.   The dynamic          test was conducted
                                                                            I)uring        the      fourth            rlltt,      the      15() v-atll l) ill-
with tile sl)aceeraft         in a @namic           tixture     (fig.
5-13)      which couhl be rotated            at constant      rates      verier   still         overheated            while         tho 250 v-amp                       in-
of roll and pitch.    Yaw              dynamic         tests were
conducted  by rolling   the             spacecraft        90 ° and
pitching.        The logic of the system     was tested
by using        an automatic    tester located   in the
checkout      trailer  as shown in figure 5-14.
  The     autopilot    passed      the static     test with only
minor      discrepancies.         However,         the dynamic
portion of tile test was terminated    with a failure
of the yaw repeater    lo<)1). A shorted    eapacita-
tor was discovered     in the repeater     motor    cir-
cuitry.     A new autopilot        ttassed both the static
and (lyn,mlic    test with no system (li_repaneies.
   The altitude-chamber          tests (fig. 5-15)         were
used to determine       the ol)eratin(_      characteristics
of the overall       environmental          control     system
 (ECS).       The astronaut        was suited       and con-
nected    into the ECS      for the first time during
the altitude-chamber        tests.       The (.hand)er       was         FIGURE   7>lS.---Ovm'all            (,vtthltltioll         of    tile   onvir(_lllllellllll
pumped       down      to a simulated           altitude       of ap-                 control       system       in    altitude          chamber.

  verler renmine<l cool.   A sub_luent              =
  tion indicated   that the flow passages      in the
  w,lter-type    heat exchanger     (cooling     plate)    were
  plugged.      It was found      that     sealant     used in
  the construction     of the cooling     plates had pene-
  trated  into tilt, flow pass:t_es  as shown in fiffure
  5-1(;.  The l,assa_es    were cleaned   and tile orig-
  inal orifices were reinstalled.     Flow tests on the
  fin'd installation              showed           that          the   system             was

                                                                                                   PWURE    5-17.---Space(.raft             during   final    silmflated        flight
                                      WITH       SEALANT                                                                     test     in   IIangar    S.

   \                                                                                                  The configuration
                                                                                                   the simulated
                                                                                                                                  of the spacecraft
                                                                                                                      flight test, was as follows
                                                                                                                                                        and is
                                                                                                   shown in tigure 5-17.
  FmuR_:     7_16,--l'lugged            inlet     part      of    cooling        lflate      for
                                                                                                      (l) The      spacecraft        was inslalle(l   on the
                               17_) v-amp       inverter.
                                                                                                   launch-vehicle        a(lapter,    and   was electrically
                                                                                                   connected    to the adapter.
      Friendshil_    7 beffan                    its hangar                 simulated                 (2) The escape     tower   without    the                            escal)e
  fliffht   test Oll Novemller                      2;5, 1961.               This test             rockets was installed    on the Sl)'we<'raft.
  was completed    on l)ecember      12, 1!)61.     When                                               (3) An absolute       minimum       of GSE   cabling
  the launch   was rescheduled     for ,lammry       196_,                                         was conne('ted     lo tile Sl)ace<'raft to sinmlate    a('-
  a rerun    of the hangar     simulated     fliffht was                                           tual /light ('<mtigurat ion as closely as l>ossible.
  made.    The second simulated       flight test series                                               (4) Two-tenths       ampere    fuses, used to simu-
  began l)ecember   19, 1961, and were successfullv                                                late squibs,   were installed     at actual squib loca-
  completed          on I)ecember               _.21, 1961.            At this            time,    tions.
  the      sp:weer'tft            was       considered                 functionally                   (5)   All      squib          firing-circuit           wiring        was       in
  ready    for humeh      pad operations.                                                          flight conligurat    ion.
     This    simulated     flight      test was designed         to                                    (6) q'he   :tstronaut                 was     suited       and      in      the
  aceolnplish     the following          test objectives:                                          spa<'ecraf!   for the systems test.
      (1) To reverify         Ilrolter     operation      of indi-                                    (7) Recorders       were com_e<'ted to monitor      all
  vi<hml systems                                                                                   squib circuits    to verify proper     tiring times.
        (°,2) To     insure        proper           operation               of    the        se-      Malfunctions      during  the simulated    flight test
                                                                                                    were as follows:
  quence    system  through      tall modes,   including
  al)ort and emergency     override                                                                   (1) The no. _ suit                    fan showed    intermittent
      (3) To (]emonstr'de     imrasystem     compatiltil-                                          flow (,hara<'teristics.                  Further  troubleshooting

  ity when      'dl systems      were operating        concur-                                     led to rep]a('ement                 of no. 2 suit fan,             no. 1 an([
  rently                                                                                           no. 2 che('k valves,                 and the negative               pre_m'e
      (4) To verify       prol)er    operation      of space-                                      relief valve.
  craft   systems    when     the flight     conditions     are                                        (2) The (_-band                     be'won  ol)erated intermit-
  simulated     as nearly    as practicable                                                        tently at low voltage.                    The beacon was replaced.


BLa.G_       _i+o,      '_.',-iir£          PHGTOG'RAP.H
                                                                                                            (3)   Mechanical       mating
                                                                                                            (4)   Spacecraft      systems test
                                                                                                            (5)   Electrical     interface     and aborls
                                                                                                            (6)   Flight     acceptance      comi)osite   tests
                                                                                                            (7)   Flight       contiguralion         sequence                                and
                                                                                                            (8)   L'mnch      simulation    including                                   reaction
                                                                                                                     cont 1"ol thruster firings
                                                                                                            (9)   Simulated      flight
                                                                                                          (10)    Pyroteclmic:      cheek
                                                                                                          (11)    Spacecraft      servicing
FI(;URE     5-18.--Launch            e()mplex          testing          of   Friendship           7.      (12)    Precount
                                                                                                          (13)    Count
                                                                                                          Each of these hnmch I)ad operations,       together
     (:3)    The            instrumentation                      time         correlation              with die troubles   encountered_     sul)sequent     de-
clock was l,eplaced       t)ecause   of :m inoperative                                                 lays, and repairs made, is discussed     for the tesl s
time-zero    light.                                                                                    made during    the ,'heckout   of the complex,                                         the
    (4) Plastic     compound      was found on a fuse                                                  sl)acecraft, a.nd tlle sl)aceeraft-launch-vehicle
block contact.       The COml)ound was removed       and                                               combination.
all fuse blocks were checked for the compound,
but none was found.
   (5) The satellite    clock jammed   during  me-
chanical reset.   It was replaced.
   (6) The suit-fan   toggle swilch couhl be made
to break contact when a slight force was placed
on the toggle while it was in the no. 2 position.
The switch was replaced.
    (7) The microphone   wires in the astronaut's
helmet were found reversed,    and tile helmet was
   (8) The emergency   10-second   retrorocket    fire
relay timed                 out in 5 seconds.                    The         relay        panel
was replaced                 and reverified.

                      Launch         Pad          Operations

    As originally     planned    the launch    pad opera-
t ions were scheduled       for completion     in 13 days;
however,      due to delays      caused     by changes    in
the spacecraft      and launch vehicle after mating,
trouble    encountered      during    tests, and adverse
weather     conditions,    the actual     time the space-
craft   spent     on the launch        pad is somewhat
longer than the 13 days as shown in figm_e 5-18.                                                       FIGURE 5 19.--8lm[.e(.raft                    on        Atlas       launch         vehi(qe
For Friendship       7 this period     extended    from                                                           Illl(lOl'ffOillff      lallll('h   f'Ollll)lox       testing.

January    3, 1962,, through     February      20, 196'2.
                                                                                                                            Launch        Complex             Checkout
Figure  5-19 shows the si)acecraft       on the launch
vehicle during    these launch    pad operations.                                                         .The launch      complex     checkout    is performed
   The launch    pad operations      are listed below                                                  to validate    :lll the comI)lex     wiring   and launch
in the      order           in which            they      are       normally               per-        pad modifications      prior to mating the spacecraft
formed       :                                                                                         with the launch        vehicle.     An autolnatic     wire
      (1)     Launch            complex     checkout                                                   checker   is used              in this operation.                          It   is shown
      (2)     Interface           inspection                                                           in figure 5-20.




FI(_I.JRE 5-20.--Automatic                               wiring che(.ker used                        to check
         cabling    involved                           in preflight    ol_ratian.                                   FI(;URE        5-21.--View               of   Sl_a(.e(.raft      adnpter               being
                                                                                                                                          mounted            on launch      vehicle.

      There            were          no         serious            discl'ep'mcies                    di_ov-
ere([         dm'in_           this            test     and         the         complex             was       de-
                                                                                                                    top     of   the    launch           vehicle         the      retropackaze            pyro-
clared           ready             for          receiving                 the         sp,lcecraft.
                                                                                                                    technics           are      checked            for     contimfity             and     resis-
                                                                                                                    tance        and    then       shorted          with       shorting          plugs.      No
                                   Interface                 Inspection                                             unforeseen               difficulties          were        experienced              in mat-
                                                                                                                    ing     sl)acecraft             13      to   the       lau,nch          vehicle;       thus
      Prior       to     mating                 the      spacecraft                   to the        launch-
                                                                                                                    the   MA-6               vehicle         was         re:uly       for     launch        pad
vehicle          adapter,                 it     was        necessary                 to    verify         that
all     items          in the            adapter               _ction            had        the      proper
clearance              and         that         there          w'ts        no debris.                Fignlre
5-21          shows          the         adapter               being            mounted              on     the
launch           vehicle.                  Following                      the     inspection               and
mating            of     the         spacecraft                    to the         launch            vehicle,
all     openings                into           this      vital        section              were      sealed.
These           _als           are        not         remored               again           except          for
emergency                work              and         just        prior         to launch.                The
adapter           and          interface                area        met         all    requirements
and    the spacecraft                                 was       then            m'tted         with         the
launch    vehicle.

                                     Mechanical                    Mating

      Mechanical                 mating                was         primarily                a mechani-
cal     tit     operation                      in     which           the        spacecraft                was
placed          on the          launch-vehicle                         ,ulapter             (fig.     5-2'2)
and       the          main           clamp                 ring       was            installed.               In         Fz(]Tzm_ 5-22,           Mechanical    matJn_"               of ,_l)aeevraft
addition,              prior         to hoisting                    the     sl)aceeraft               to    the                                        to adapter.

                            Spacecraft         Systems           Tests
                                                                                                  thruster   assemblies    as a result   of a (lesi_m
     Sl)aceeraft       systems       tests    were      l)erformed                                change.    The silver batteries   for the auxiliary
 1)rimarily      (o ('heck the Sl)acecraf(         systems func-                                  1)ea('ons were also repla('ed.   All of this sl)eeia]
 tit)redly    and to check the remote-('ontrol                  (-al)a-                           work resulted    in a 1-day delay in testing.
 bility    from tile blockhouse.            Figure    5-23 shows
                                                                                                              Flight     Acreptanee               Composite            Test
 tile spacecraft       blockhouse        rcm_)les.      Following
 tiffs test the spacecraft             was ready       to pr(x, ee(|                                The     flight      a(.cel)tam.e          ('omposite               test    was de-
 with tests which           integrale      the l:mn(.h        vehicle                             si_zned to prove           eoml)a(ibility                 of the Sl)a('e('raft
 and the spacecraft.            1luring     the_    tests trouble                                 radio-frequen(.y            sy,_tems with                (he At taut i(_ Mis-
w,ts exl)e.rien(.ed     with tile coolant quantity         indi-                                 sile Ran,_e and the bumeh           vehi('le and (o l)rove
('ating  system      indicator,      the auxiliary      bearom                                   that Sl)a('e('raft   and ]aun('h-vehi(qe       systems      do
:rod minor       discrepancies         in _roml(l-servicin_x                                     not     _enerate      )'adio-frequem.y       imerferen('e.
equipment.      (GSE)       cal)lin_.     These items were                                       This test was :dso used (o verify             satisfa(-tory
('orrected            and        those      parts   of this system     tests                     operation      of Sl)a(.e(.raft   n_dio frequency        with
required             were        rerun      to valid'lte   the changes.                          CrSE ('allies installed.        This test was COml)lete(I
                                                                                                 with only a mine)" (lis(,rel)ancy                            whirh           required
                                                                                                 'l change of a freo)t c]_eck valve.
                                                                                                    At this      point,   because of a projected      (,hange
                                                                                                 in launch        schedule,    (he order   of testing     was
                                                                                                 changed         and     the    launch   simulation       was
                                                                                                 scheduled       next.

                                                                                                                         Launch          Simulation

                                                                                           °°*      The launch    simulation     test was desi_,med to
                                                                                                 validate  the Sl)a('ecraft  'tnd ]amlch-vehicle    sys-
                                                                                                 tems in a launch configuration        and to evahrtte

FIGURE            5--23.--Blockhouse                 consoles        for     monitoring
     spacecraft          operation          during         the      launch       complex

                    Electrical         Interface         and      Aborts

     The      electrical           interface           and       aborts      test    vali-
d','_ted the           spacecraft-launch-vehicle                             interf,'w_e
compatibility              as well as _(tundan_                              electrical
and radio-frequency           paths.    For this test, GSE
cables     were    installed.        By use of the GSE
cables this test, also provides          Jr mea,ns of check-
ing the redundant             paths    umd     for abort     _t
various     times during       the prelaunch      and launch
)nodes.      This test was run with only minor dis-
crepancies      which were corrected,         and then those
portions      of the test which         h'td contained     the
discrepancies      were      rerun    to    v'didate                                  the
changes.      However,      during     preparations                                   for
this test faulty     autontatic    roll thrusters                                    were
discovered     and these were ret)laced.                                        At    the
                                                                                                 FIGURE   5-24.--Emergenoy               egress       tower      ramps        in   l)]a('o
same     time,   heat  sinks were   adde(1                                      to    the
                                                                                                               during        emergency            egress      tests.

tile launch-day       1)rocedures.     At tile same time                       cult indicating     a need for oxygen.        With    the
this tesl provides        an opl)ortunity     to practice                      drol> in pressure,     the regulator     would   supl>ly
emergency      egress    l>r<)cedures   (rig. 5-24).    No                     oxygen     to bring    the system    u 1) to operating
problems         were    encountered          in this test.                    l)ressure.    With   the addition     of the conslanl
                                                                               bleed orifice it was not expected     that the dem'tnd
       Flight     Configuration       Sequence       and Aborts                regulator   wouhl function      often.      Troubleshoot-
                                                                               ing following      the simulated         flight     indicated
    The flight configuration       se(luen<'e and aborts
                                                                               that one of the dial)hr'tgnns      in the demand re_l-
test, l)r<>vitles for compatibility        tests of space-
                                                                               later had developed       a small leak.         Since it was
cr'tft    systems    and   launch-vehicle        autol)ilot.
The test also further        che(.ks the abort        modes                    very difficult,  to rmnove the regulator              bee,rose
                                                                               of its location,    extensive    testing      was made to
with the spacecraft         in a flight   configuration
                                                                               be sure that the troul)le            truly was in the regu-
simulating     lsumch     and flight.    This test was
                                                                               lator.     Finally     the decision      was made to remove
completed   with no ditticulties.
                                                                               the regulator        and it was found that the problem
   The l,tunch    simulation    test, was repeated      for
                                                                               w,ts not in the regul'ttor              but in the plumbing
practice        for the launch        crew.
                                                                               to the regulator.         ]Iere, a leaky joint was found.
                                                                                   The_       incidents     pointed      out two principles
                        Flight    Safety    Review
                                                                               that should         be observed        in design:     First,  in-
   A    flight     safety        review    board     was      convened         accessil)ility      of the demand          regulator     made it
al)l)roximately   five            days 1)efm_e launch   to re-                 difficult    to check the regulator            adequately    and
view the Sl)ace<'raft             history.  This review    was                 (.au_d     delays      at a crucial     tinte    in launch
conducted     by the ol)erations      directors.    The re-                    preparations         (X-4     days).   Secondly,      inade-
view board was comI)O."o--d of representatives              of                 quate test l)oints ntade it impossible         to diagno_
the Mercury        l)roje('t ()flice, the Flight     Safety                    t he problems      1)roperly.
()flit.e, the astronauts,     and the Preflight     ()pera-                        After    the regulator        was replaced     and the
tions Division.         This board reviewed      lhe status                    plumbing        repaired,     another  check was made
of all systems,      al)proving     all devi'/ti<>n    ft'onl                  with the 'tstronaut         in the suit circuit.       These
specifications    found     during     spacecraft    check-                    <'heu.ks indicated      sonte improvement   in the oxy-
out.     It was the resl)<msil)ility      of this board to                     gen consmnl>tion          rate_ but it. was still much
commit the Sl)acecraft       to launch.                                        higher than it, should have been.
                                                                                  After  a detailed    ,malysis   of the system         it was
                          Simulated        Flight                              concluded    that    there   ntnsl; be a leak           in the
                                                                               a stronaut,'s    pressure    suit.    Prior     to any test in-
   The simulated       flight test coml)letely    checks
                                                                               volving      the suit, it was pressure          tested at 5 psi
all sl)ace<'r'tft systems during    a simulated    flight
                                                                                (fig. 5-25).      Ilowever,       the suit,   during   normal
from     lift-off to landing.     The test also l>er -
mits • check of the automatic           launch-vehicle
abort systent at lift-off    + 200 seconds.
   During   the simulated     flight test on X4   days
for the attempted      launch    on January   23_ 1962,
it was noted that the oxygen consumption           rate_
with Astronaut        Glemt in the system,         was high
intermittently.       Checks    the l)revious      day with
Astronaut       Carpenter     in the circuit      had indi-
cated normal      consumI)tion     rates.
   Frientlship     7's environmental      control     system
was different     than any of those previously          flown
in that it had an orifice in the oxygen               supply
that, provided       a constant     flow of about        1_000
co/rain.     This flow was adequate        for all nomna.1
astronaut     demands.      Originally_   the environ-
mental    system    contained     a demand    regulator                        FIGURE 5-25.--Pressure         tests of astronaut's    pressure
which sensed a drop in pressure         in the suit cir-                                                 suit at 5 psi.


                                                           BLACK         AND      WHJ, E P/-_O T_'(?P, AP_
                                                                                 '' ""      ,.
                                                                                           tions as near to all flight conditions     _ possible.
                                                                                              Upon    checking    the system   after   the previ-
                                                                                           ously mentioned       faults were competed,      it was
                                                                                           found that the system used oxygen          at approxi-
                                                                                           mately   the 1,000 e('/min     rate provided    by the
                                                                                           constant   bleed orifice.
                                                                                              Since     the     constant        bleed      orifice    was added       to
                                                                                           an already    autonmtic    system, this bleed changed
                                                                                           the pressure     levels in a delicately  balanced  sys-
                                                                                           tem.    Without     the bleed the small leaks in the
                                                                                           suit circuit    would   have been inconsequential.
                                                                                           However,      with the bleed, the suit leakage      was
                                                                                           causing    the demand      regulator  to flow extra
                                                                                           oxygen    into the suit, and thus the oxygen       con-
         FIGURE     _-')t_.--Low        pressure       tests     of suit.                  sumption     was increased.     This seemingly     small
                                                                                           change,   therefore,   produced    large effects on the
                                                                                           I)evformance     of the syslem.     It must I)e pointed
                                                                                           out that the addition       of the constant   bleed did
                                                                                           provide      additional    safety   by                reducing     carbon
                                                                                           dioxide      concentrati<m      in the                suit circuit     and
                                                                                           provided    positive oxygen flow regardle_     of the
                                                                                           regulator   operation.
                                                                                              Of additional     interest was the fact that none
                                                   WRIST       CUFF SEAL----_
                                                                                           of these discrepancies       were noted  during    the
                                                                                           altitude-chamber     tests even though the same test
                                                                                           procedures     were used.   Apparently, the position
                                                                                           of the cuff se.fls during   this test prevented    them
                                                                                           from leaking.      Also, the plumbing       le'tk in the
FIOURE    5-27.--Pressure-suit                gloves     showing            cuff    slip
                                     joint.                                                (lelnand regulator    plumbing     must have occurred
                                                                                           subsequent   to the chamber     tests.  This indicates
flight,  operates  at a pressure    of only a few                                          the desirability             of repeating         tests    of systems      at
                                                                                           discrete  times.
inches of water above cabin pressure     and would
ol)erate  at 5 psi differential  only if the cabin                                           A simulated             flight     was repeatexl          to verify     the
should     become    decompl_essed.      No leak checks                                    changes      in the environmental                     control   system.
pI_viously      had ever been made at these            low
                                                                                                                   Spacecraft        Servicing
pressures.      Inspection     of the suit cuff and zip-
per seals indicated        that pressure   was required                                       Various      items of work were then performed
to effect a good seal at these points.         Upon test_-                                 to l>nt the sl)ace('raft   in a flight-ready      condition.
ing of the' suit at low pi_ssm_            (fig. 5-26)   it                                The_     items are filling the oxygen bottles, serv-
was found that the cuff seals at the                              wrists           (fig.   icing and installing      the onboard       tape recorders,
5-27) leaked as the cuff was rotated.                                                      servicing     the landing-bag       release    system,    and
   This particular               experience        leads       to some addi-               many     other     items of a purely       mechanical      na-
tional conclusions                :                                                        ture.     This work was accomplished              in the al-
   (1) The necessity     for functional                             testing           at   lotted     time     and      the    l)recomtt      was scheduled.
the launch site is proven again.
                                                                                                             Preeount         and   Launch        Count
   (2) The necessity    for integrated                           system            test-
ing is demonstrated.                                                                          I'recount.--The         countdown     is performed      in
   (3) The fallacy         of assuming     that    one test                                two parts.          The first part,   known     as the pre-
condition      is equivalent    to another      is pointed                                 count, is primarily        a check of the various     space-
out.    Testing    should be conducted      under condi-                                   craft    ss'stents.     Following    completion      of this
                                                                                           first part. of the countdown,    there                    is an approxi-
                                                                                           mate 15-hour      lind for pyrotechnic                       cheek, elec-

trical connection,                    servic-
ing and surveillance.Both the precount nd a
the 15-hourhold operations  wereperformed
without discrepancies, the final part, the
I'mnch count,was started. This count pro-
ceeded T-13 minutes at which time the launch
was canceled     for         the    day    because     of   adverse
weather  conditions.
   Di_eultie._ encountered      after cancellation.--
After the cancell'dion    at. T-13 minutes on Janu-
ary '27, 1962,           it was     decided   to replace         the
carl)on dioxide          absorber    unit 1)ecause it had        ap-
proached   the end of its service  life.    The per-
oxide system also had to be drained      and flushed
to prevent   corrosion,  and the pyrotechnics       were
disconnected     and shorted   as a _fety     measure.
This work was accomplished         in 1 day.    At this
time, some of the launch-vehicle        systems     were
being i_validated.      During   the tanking    test of
the launch vehicle, a leak was discovered         in the
inner   bulkhead        of the fuel tank       and required
                                                                       FW, URE 5-2_.--Lift-off          of    MA-6      from      launch   complex
4 to 6 days to repair.              The repairing       of this
                                                                                           at    Cape    Can,tvernl,       Fla.
leak, the necessary         retesting     and launch      prep-
aration    after    tile rel)air      had been made,        and
other   operational        considerations       dictated     re-       T-90     to T-55     final       mechanical         work and space-
schedu!ing  of the launch for February    13, 196'2.                   craft     checks     were        made    and        the service was
The launch   date w_s resc.heduled    to February                      evacuated      and moved away from the launch ve-
14 sometime   later because  all of the aforemen-                      hicle.     At approximately        '1'-35 mim_tes     filling
tioned    work     had     not been       completed.        During     of the      liquid-oxygen     tanks     began    and     final
this delay, all six flight t/atteries       and the para-              spacecraft       and ]autwh-vehi('le      systems    checlc_
chutes   were replaced.        Portions     of the normal              were started.        At T-10 mimltes       the spqcecraft
complex    testing     were rerun       to verify    launch            went on internal   power,   and the launch vehicle
st.ttus.  The     pre('ount     was starte(l      again    on          went to inter,ml     power    at T-3 minutes.           At
February     13, 15, and 16, but it. was canceled                      T-35    seconds  the   spacecraft     mnt)ilical       was
each time because         of adverse      weather     condi-           ejected   and at T-0 the main       engines      started.
tions.   The launch         was then      mscheduled      for          At about T + 4 seconds l ift-off occurred        and the
February    20, 1962.                                                  flight   was underway                 as shown      in figure       5-28.
   Launch   eount.--During      the launch count on
                                                                                          Concluding             Remarks
February     '20 all systems   were energized   and
final overall    checks    were made.     The count                        In conclusion,         the flight success         of Mercury
stared     at T-390 minutes           by installing       and con-     has in t)art          been achieved         by:     (1) repeated
necting     the escape-rocket          igniter.      The service       testing     to uncover        systems    weakness:        (2) par-
structure      wqs then cle'u'ed          'm(l the spacecraft          titular     attention      to details    tlmt might         lead to
was powered           to verify       no ilmdvertent         pyro-     nlission      failure,     (3) integrated         fli_zht simula-
technic     ignition.       The i/ersomm]         then returned        tions    that      assured      compatibility          among      the
to the _rvice          structm'e      to prepare        for static     sl)acecraft       systems      and among        tile sl)acecraft      ,
firing of the reaction            control     system at T-250          launch      vehi('le, 'tad range, and (4) a continual
minutes.        Following        the reaction      control   static    updating        of the sp'/cecraft      configuration        taking
tiring    the spacecraft           was then       prepared       for   full advantage        of previous    flight    experience.
astronaut;       boarding        at T-120        minutes.       The    This policy has led to lengthy         checkout    periods
hatch was put in place at T-90 minutes.                       I)ur-    at C'q)e     (_anaveral;    however,     a single     flight
ing installation        a bolt was broken, and the hatch               mission    failure   would have caused even longer
had _o be removed             to replace      the bolt.      From      delays   in the overall     Mercm'y     program.

                           6.      FLIGHT          CONTROL             AND              FLIGHT                          PLAN

By CHRISTOPHER C. KRAFT,   Jr., Chic/,                    Flight Operations Division, NASA                                Manned                     Spacecra]t Center;
    TECWYN ROBERTS, Flight Operations                      Division, NASA Manned Spacecra/t                                Center;                    EUGENE F. KR._NZ,
       Flight Operations   Division, NASA Manned Spucecra/t    Center;                              and             C. FREDERICK                     MATTHEWS,               Flight
       Operations  Division,   NASA   Manned Spacecrajt Center

                            Summary                                    (lelermined                  l_y his ability   to I)erform      in this
                                                                       environment                   an(I, here again, slx_('i fic test s were
    A nunlber       of malfunctions           occurred       during    set up to ai<t in this                 The astro-deterndnat                      ion.
this     flight   which     caused     some     concern      to the    ll;l.ll{   x,VHS        10            of oul.mrd
                                                                                                     t)el'fOl'lll             Ill;ll]II_IZelllel]|

flight   control   team.   These included     the              mal-    systems  such as cabin and suit cooling,   use of
function     of the automatic   control   system,               and    a-c an(1 d-c p()wer, and so forth, and he was to
what later proved     to I)e the false indication      of              rel)ort       on lhe              l)erfm'mance                           of all         of tlw space-
heat-shield  deployment.      However,    the presence                 cl'afl     sys|elllS.                  T]le     _lSll'Olttlllt                _,V:I.S   |0   <leterlnille
of the astronaut    onhoard     the spacec, raft made                  his ability to  IlaVigate  I_V both earth                                                      and star
these malfunctions       of a In|nor    nature.     The                reference.   He was to perform      visual                                                      observa-
astronaut's     ability  to evaluate    the performance                tions of astronomical     and so|entitle                                                       interests,
of the spacecraft        systems    and take corrective                including       weather    observations.         Finally,     he
action,     and his excellent     method      of reporting             was to report on any unusual           l)heno,nemt      within
these results     to the ground,     resulte(1 in the suc-             or out side of the sliacecraft.         All hough the mal-
cessful completion        of the MA-6 flight.                          fu,wtion     of some of tim Slmcecraft          systems    may
                                                                       h:we altered      the flighl plan |o some extent,          it is
                                                                       felt, tlt:t| the flight test results      aclfieved    a great
                                                                       majority      <)f the objectives     laid down an(I tlrtl
    It is the intent of this report to give a brief
                                                                       generally     sl)eaking   the flight tesl v+-as exl remely
 outline   of the flight   plan of the MA-6       flight
 and primarily      the procedure     used to perform
                                                                           The following        (h,,,_q'il)lion  of the mission     is
 flight control.     In addition,   some of the perti-
                                                                       given in chrom)logit'al            order  so that al)precia-
 nent flight test results     will be given.
                                                                       t ion of t lie flight-corn     rol lIroblems can be under-
                                                                       stood, and in this re:tuner the flight tests results
                          Flight      Plan
                                                                       are given.
    A detailed  outline  of the flight            plan    is given                                                   Countdown
 as follows :
    The astronaut     was to evaluate               the    various        The countdown    for launching    tlte Mercury-
 modes     of control     available     in the spacex'raft       an&   Atlas  vehicle is conducted    in two parts.    The
 to report     on the capabilities        of these various             first p,trt is conducted       on the day I)efore      the
 systems.      He was to determine           his visual ref-           launch    and lasts al)l>roximately      4 hours.   I)ur-
 erence capabilities,       that is, his ability     to deter-         ing this Iierio<l detailed    tests of all of the space-
 mine attitude      by observing      the horizon       an(t/or        (;raft systems are l>erformed       and those interface
 tim stars by using the window and l)eri_'ol)e               and       connections    important    to the_ systems are veri-
 his ability    to ot)tain this reference       on both the            tied.    This part    of the countdown          was con-
 light    and dark       sides of the earth.           ('ertain        (tucted with no major problenls         or hohts result-
 specific maneuvers         were set u l) to provi(te     infof        ing.   Approximately       171/, hours separated      the
 mat|on      on this      capability.      The     effects      of     end of this count 'tnd the heginning         of the final
 weightlessness      for extended      periods    were to he           countdown,     and during       this period   the spat'e-


PRL_"_I_P.4G_                   BLA_K .NOT FILleD
PAG                 mr[mto Zu
 (_raft pyrt)teehnies     were installed   and <.onneeted                                lion.      The            ('u(ofl       conditions          obtained       were
 and certain     exl)emtat)les     such as fuel and oxy-                                 excellent.
 gen were loaded.                                                                            Table     (;-I presents      tile a('(ual    ('utoff ('el)all-
    At T      300 minutes      tile eou)mh)wn     was re-                                (ions    that     were obtained.          A eoml)aris()n        of
 sumed and 1)ro_ressed        with<!u( any mmsual           in-                          the l)lammd         and    actual      times    at whi('h     the
 stam'e until T--12()     mhmtes.        I)tLring this pe                                major       events    o('vu)'re(l     are    given      in fable
 tied ad<li(ional    spacecraft      systems      (.he('kouts                            (;-It and the times at which all of the he(work
 were   i)erformed     and     the major        1)ortion      of                         sites a(.(luired   and lost ('onlaet     with the space-
 the laune]l-vehiele    cotmt(lown       was 1)e_un.        At                           ('raft are l))'esente(l  i)) (al)]e 6-11I.
 T-120     mi)mtes   a l)uilt-in   hohl of 90 mimm, s                                        I( mi_'ht    be noted    that   the flight   test ex-
 had been scheduled           (o assure    (hal all systems                              perience  whieh     had been aehievexl on the pre-
 had been given        suflieien( lime for ('heekot,t, I)e-                              vious Mer('ur,v-A(las     orl)ital    flights, that is, the
 fore astromtut      insev(i()n,     l)uving   this l)erio(l a                           MA-4 and MA-5,         had given the flight control
 l)roblem   (levelol)ed       with ILL(' ,(_rui(la)we sys(en)                            learn an exvel]en(     Opl)ortunity       to exerci_    con-
 rate beacon in the hmn('h vehi('le ,'ausi),_ an ad-                                     trol over tim mission.         "' flights    were. of
 ditional  4o mhmte          hold. and an :,hlition:Ll       I()                         ('ourse, much more (lifli('ult to ('ontrol and com-
 mhmtes   were re(luired                  to repair a broke)) mh')'o                     plete    su('('essful]y   t)e('ause    of the lack of an
 l)h<me l)ra('ke( in the                  ast)'()))aut's helmet after                    astromm(         wi(hin  (he spacecraft.      All of the
 the    as(rotator             insertion          l)rO('edm'e    had been                analyses      and decisions      had to be made on the
 started.      The            eomLt(h)wn           l)r+),'eede(l  to T-t;()              I)asis    of telemetered         information    from  the
 minutes      when           a 40 minute           hohl was require(l       to           spa('eeraft..            The       l)rese)we      of an astronaut         made
 rel)la('e a l)roke)l Ix)It l)e('ause of misalinement                                   the flight (('st much more simple t<) (:omplete,
 on theslm('e('rafl'shatehattavhment.                 AtT-45                            l)rima,'ily      (m)he basis of ttst,ronatlt   observat ions
 minutes,    a 17) minute       hohl wm_ required        to add                         and his eal)al)ility      of systems     man'l_ement.        A
 fuel to the, lamwh          vehiele;     and at T-22       min-                        mamled        flight, however,    makes the job of moni-
 utes an additi(mal         2, mi)mtes       was required     for                       tol'ing     s])a('e('raf( i)erfornmnee       more coml)lex
 tilling the liqui(l-oxytze)1         tanks   a.s a resuh of a                          tx, cau_, of (he large )mmber          of backup      and al-
 minor     malfun('lion         ill (he ground          SUl)l)Or(                       ternate     sysl(,ms from whi(']l the astronaut         could
 equipment      used to imml) liquid ()xy_e)) into the                                  (' h ()oy;e_.

 launch    vehicle.       At T-6        mimm,s     and ?0 see.-                                                            Mission        Rules
 on(ls,     a 2 mim,e              hohl    was        required        to make       a
                                                                                           l)revious    to all of the flights,    mission    rules
 quick check of (he network           eoml)u(er   at Ber-
                                                                                        for all l>ha.'-;(_sof the el)era)ion  were estal)lished
 mu(la.    In _enera],       tim ('onnl(lown    was very
                                                                                        be_zil,ning    with !he ('ountdow)t     and ending  with
 sn,oot]L ;l.)L(l ex()'emely    well execme(l.    A feel-
                                                                                        (]w. re(.()very.    The development        of these rules
 ing of ('onfi(len('e     was ),)ted    in all (',m('er))ed,
                                                                                        _v;,_ slarte(l a (.oz_si(h.ral)]e length of time tx, fore
 in('lu(ling  tile astromtu(,   and it is l))'()l)al)ly n,ore
                                                                                        any (,f lilt, Mer('m'y flitsht ()perat ions, and Ix, ga)t
 than signiii('ant     tlm( (his feelin_   has existed on
                                                                                        (<) deveh)IL at tile same time as (he flit£ht ('on!re]
 the last ihree .Mercury-Atlas         lamwhes.
                                                                                        e<Jm'epts.    The mission      rules were es(al)lished
                                                                                        in a)) effort t(> take into a<:('otmt every ('on('eiva-
                              Powered            Fligh!
                                                                                        l)le situati(m    whi(_l) ('ould (>('('ttr onl)<>ard the
      The   launch         ovvurred            at !):47:39       a.m.e.s.t,        on   Sl)a('e('raft:           is, ('(msider:tti()n
                                                                                                                 (hal                      was tziveu to
Fel)ruary         20, 1962,   TILe 1)owered    portion of                               ])or   h    the   ast        and
                                                                                                                  rOlmUt   the    sl)a(,eeraf)     systenLs,
the flight        which lasted 5 )nhmtes    and 1 second                                aml t()all ()f tile (',meeival)le          _)'oum[ e(lUil)ment
was COml)letely     normal    and the astronaut     was                                 f;tiln)'es    whi<'h ,'ould have a (life('( be;u'i),_             on
able (o))lake  all of tile l)la)med ('onmmnieations                                     the llitzht operati,,n.          In a(lditio)l,        rules    were
and    ol)se)'vations                  throughout      this   period.                   estal)lishe(l    in an (.fief( (o handle           a htrge mma-
Throughout       this             1)orl ion of the fli_'h( no abnor-                    l)<,r ()f lau)wh vehi('le malftm(qions.                  These, of
mMities     were noted      in either    flw sl)aeecrafi                                ('()u)_e, deal!     l)rimari]y        with (he effects of a
systems    ov in the astronaut',,-;    physical    condi-                               su(l(h, iL cutoff (_()),(lition aIL(l its effe('! on the
tion.   The lamwh-vehi(qe       guidan(,e   system per-                                 sl)a('e('raf(           Jli_rht     thereafter.           These   yules     were
formed    almost  l)erfeetly,   and I() seconds      after                              t'.'.(al)lished          for (he pvelaun('h,    i>owered                  High(,
(qlt()l'_   lhe   (!Olllplltel'       ,_;LVe      a   '_()'"   l'eCOllLlllend_l-        and orbital              flight l)ha_,.s of the mission.

                                                                              TA riLE                    6-1.--P/angled                                      and         Actual             Flight            (br_dition,s

          Cutoff           conditions:
                     Altitude,                 ft_                                                           .                                                                                               _                                                           528,         381
                     Velocity,                 ft/sec           ..............................                                                                                                                                                                               25, 730
                     Flight-l)ath                     angle,                (leg                                                         ....                                                                                                                            -      0. 047
          ( )rbit        parameters:
                     Perigee               altitude,                 nautical                  miles                     ...........................                                                                                                                            86.     92
                     Apogee                altitude,    nautical                               miles                                                         .......                                                                                                         140. 92
                     Period,              rain : sec ......                                                                                                                                                                                                                   88 : 2.9
               Inclination        angle,                                (leg           ..........................................                                                                                                                                               32. 54
          Maximum         conditions:
                     Exit          acceleration,                        g units                   ........                                                                                                                                                                            7. 7
                     Exit          dynamic                   pressure,                     lb/sq          ft                                     .....................                                                                                                                982
                     Entry             acceleration,       g units ..............................................                                                                                                                                                                     7.7
                     Entry             dynamic       pressure,    lb/sq       ft ............................                                                                                                                                                                         472

                                                                       TABLE                       6         l l.         Sequence                      qf       Eeents           During                  A/A_6'            Flight

                                                                                                                      (All         times           are          Eastern           Standard)

                                                                                                     Event                                                                                                         Plann(,d      time               _,            Actual   time,
                                                                                                                                                                                                                      hr:min:sec                                  hr: inin :s(,c

          Booster-engine                          cutoff             ....              --- .......................                                                                                                       00:02:11.             4                      00:02:09.                6       -
          Tower     release                   .....                                _     ......                                                                                                                          00:02:34.             2                      00:02:33.                3

          Escape            rocket                firing        ....                   _ 7 .....                                                                                                                         00:02:34.             2                      00:02:33.                4
                                                                                                                                                                                                                                                                      00:05:01.                4
          Sustainer-engine                            cutoff                (SEC())          ___                     ..........
          Tail-off    complete_                         _                     :_    ........                                                                                                                             00 : 05 : 03. 8                              00:05:02

          Spacecraft                  separation=                       ._ _                                 .........                                                                                                   00 : 05 : 03.        8                   00:05:03.                    6
          Retrofire                initiation                      ........                                                                                                                                              04:32:58                                 04 : 33:08

          Retro           (left)          No.         1                       .................                                                                                                                          04:32:58                                 04:33:08

          P, etro         (bottom)                   No.         2 ................                                                                                                                                      04 : 33:03                               04:33:13

          Rctro           (right)             No.          3                           .................                                                                                                                 04:33:08                                 04:33:18

          Retro           assembly                   jettison               ............                                                                                                                                 04:33:58                                        0')
          0.05g          relay         ...................                                                                                                                                                               04 : 43 : 53                             04:43:31

          Drogue             parachute                       <teployment                                            ............                                                                                         04 : 50 : 00                             04:49:17.2

          Main           parachute                   deployment      ..............                                                                                                                                      04 : 50 : 36                             04:50:              I l
          Main           parachute                   jettison   (water         impact)                                            ...........                                                                            04:55:22                                 04:55:23

           • Preflight.                  calculated,                     based              on          nominal                   Atlas          performance.
           b Retro               assembly                    kept           on      during                reentry.
             The          0.05g            relay             was        actuated                       manually                     by       astronaut                   when          he    w'ts      in     a "sm.dl             g field."

       Because                   of      the         <'Oml)lexit                       5     of         the           entil_               oper-                                                             Flight            Test           Results

_Ltion         and           the           crit        i('al           time             element                        of         Ix>wered

flight,             it     was             felt         and              I)orne                   out            t)y          flighl              ex-                          The          l_st       of        tJfis       paper            deals             primarily                      with

perience                 that          such           a set            of         rules              were                an       .d)solute                              the      flight             test,        results            and           flight             control                prob-

necessity.                       ()f          <'orate,                  it.       is       impo._ible                             to       think                         lems           whicll               developed                   throughout                          the            tin,,e-

of        everything                         that              can            happen                      lint              if      most               of                orbit          mission.                   The             obsmwations                        made              by         the
                                                                                                                                                                         astronaut                  and          his      evaluation                     of     the      mission                   _re
t he       <'ontintzenc.ies                             have                  been             ant           icit)ate(I                    along

with          the          procedures                            to         handle                      these               situations,                                  presented                   in      paper             12      by          Astronaut                     John                 H.

the        time           av,dlable                     can            I_        u_,d              to        concentrate                           on                    Glenn,             .It'.

the         unexI)e<'.ted.                             The                  occurrence                              of           the            heat                           After            separation                    of      the      sl)acecntft                       from              the

shiehl            del)loy                 signal                in       this            fligh!                  is an            examl)le                               launch             vehicle,               the       astronaut                    was         given             all        the

of     one          of      these             ullfol'eseell                            (_ir(mmsla.nces.                                                                  pertinent                  (tata          involved                 with          orbit           par,_meters

                                                             T_,BL_:                   6-111.--Network                 Acqui,sitio_t                      Time._'   /or   MA-6          Flight

                                                                                                                 Telem(qry                 signal     duration,                           VoieP         reception
                                                                                                                                      hr:min      :see

                                                                                                                  Acquisition                              Loss           Frequency               ])nr'ttion,        hr:min        :sec

     Canaveral                     ...........                                                                     (l() :00 : 00                    00 : 06 : 20           Ut]      F            00 : 00 : 00       to 00 : 05 : 30
     Bermuda                        ..................                                                             00:03:02                         00:10:26               Utt      F            00 : 03 : 30       to 00 : 09 : 30
                                                                                                                                                                           IIF                   00:11:00           to few       sec
     Cltn:try               Islands                 ...........                                                    00:14:15                         00:21:23               UII      F            00:15:00           1o00:23:00
                                                                                                                                                                           ItF                   00:13:00           to 00:14:00
     Atlantic                 Ship                      .....                                                      Not,         in

     Kano            .................                                                                             00:21:13                         00:28:21               UIIF'                 00 : 22 : 00   to     00 : 29 : 00
     Zanzibar                  ...............................                                                     00:29:51                         00:37:51               UIIF                  00 : 30 : 00   to     00 : 38 :00
     Indian              ()ceall          Ship              .....                                            ]     00:40:02                         00:48:31               UII F                 00:41:00       to     00:48:00
      Muehea               .....................                                                                   00:49:21                         00:57:55              UttF                   00:50:00       to 00:58:30
     Woomera                    ....................                                                               00:54:00                         01:02:41               UIIF                  00:56:00       to01:03:00
     Canton                 ..................                                                                     0l:09:19                         01:17:42               UIIF                  01:09:0(11o           01:15:30
     IIawaii             ....................                                                                      Not          ill

     California                    ......................                                                          01:26:41                         01:31:23              UIIF                   01:27:30       to01:30:00
                                                                                                                                                                           ttF                   01:19:00       to01:25:30
                                                                                                                   01:26:47                         01:33:25               UIIF                  01:26:00       to     01:33:30
                                                                                                                                                                           tIF                   01:20:301o01:26:00
     G tlttytll'ts                   ...........                                                         i
     Texas               .............                                                                             01:251:24                        01:36:18               UIIF                  01:33:301o01:39:00
                                                                                                                                                                           ItF                   01:28:30           to01:56:30
     Eglin ...............                                                                                         01:32:00                         01:37:05
     Canaveral          .......                                                                                    01:33:20                         01:40:03               UH F                  01:33:30           t,o 01:40:00
                                                                                                                                                                           HF                    01:28:00           to 01:43:00
     Bermuda                                          ..........................                                   Ol :36:38                        Ol :43:53              Utt      F            01:33:30           to01:42:00
                                                                                                                                                                           HF                    01:43:00           to 01:49:30
     Canary                 Islands                .......................                                         01:47:55                         01:53:58               UtI      F            O1:49:00           to 01:55:00
     Atl,mtie     Ship                      .....                                                                  01:51:54                         01:58:31               U H F                 01:54:00           to01:58:00
     Kano ............                                                                                             01:54:47                         02:01:21               Utl      F            01:58:00           to 02:02:00
     Zanzibar                  _                                                   -                         I     02:04:05                         02:10:5l               UHF                   02:04:00           to 02:    I 1:00

     Indian              ()eean                Ship                                     _                    [     02:12:17                         02:22:09               UtIF                  02:14:00           to 02:23:(10
                                                                                                                   02:22:51                         02:31:23               Utl      F            02 : 25 : 00       t,o 02 : 32 : 30
     Muehea                 .........                                                                        I
     Woomera                    ...........                                                                        02 : 27 : 36                     02 : 35 : 45           Utl      F            02:28:00           to 02:37:00
     Canton                ........................                                                                02:42:51                         02:49:45               Utl      F            02:41:30           to 02:49:00
     Hawaii                                                                                                        02:49:01                         02:55:19               UH F                  02:49:00           to 02:55:30
     California                    ..........................                                                      02:58:11                         03:04:48               UIIF                  02:58:30           to 03:04:30
     Guaymas                    .............................                                                      02:59:59                         03:06:44               Utt      F            03:00:30           to 03:04:30
     Texas                                                                                                         03:03:14                         03:09:39               UHF                   03:03:30           to 03:10:30
                                                                                                                                                                           HF                    {)3:03:30          to 03:10:30
     Eglin .............                                                                                           03:05:35                         03:12:07               Utt F                 03:07:30           to03:12:30
     Canaveral          ....................                                                                       03:06:51                         03:13:46               (TI1F                 03:07:00           to 03:14:00
                                                                                                                                                                           tt 1,"                03 : 05 : 00       to 03 : 13 : 30
     Bermuda                       ...............                                                                 03:09:56                         03:17:03               UIt      F            03:00:30           to03:16:30
     Bermuda                    ..................................                                                                                                         ttF                   03:17:00           to03:18:00
     Canary                 Islands                ......................                                        Not      in                   ........                    ttF                   03:21:00       to     03:25:00
     Atlantic                 Ship          ........................                                               03:24:44                         (13 :32 : 25           UHF                   03:26:00       to03:34:00
                                                                                                                                                                           tt F              03:26:00           to03:27:30
     Kano            .................................                                                           Not      in
     Zanzibar                 ...............                                                                    Not in                                                   tIF                03:41:00           to03:42:00
     Indian              Ocean                Ship              ......                                            03 : 46 : 55                     03 : 56 : 4q           ttF                03:48:00           to03:56:00
     Muchea                 .......                                                                               03:56:31                         04:04:12               UHF                03:58:30           to 04:04:00
                                                                                                                                                                          tIF                03:57:00           to 03:58:00

                                  TABLE 6-lII.--Network                         Acquisition                   Times      for ._IA-6          Flight--Continued

                                                                                            Telemetry            signal   duration,                              Voice     reception
                                                                                                            hr : rain : sec

                                                                                              Acquisition                  Loss             Freq    lien    Cy        l)uration,          hr:   min    : see

     Woomcra              ..............                                                         04:03:16               04:06:19             UttF                  04 :04 : 00         to 04 : 07 : 00
     Canton          ......                                                                   Not     in                                    ltF                    04:15:30            to04:21:(t0
     Hawaii         ..............                                                               04:21:49               04 : 28 : 49         UHF                   04:19:00            to 04:40:30
                                                                                                                                             IIF                   04:20:00            to 04:20:15
     California               ........                                                           04:31:17               04:37      : 57     UttF                   04:31:30            to04:38:30
                                                                                                                                            HF                     04:19:00            to 04 : l/) :15
     Guaymas        ..............                                                               04:33:44               04 : 3(,} : 49       UttF                  04:34:30            to 04:40:30
     Texas ...............                                                                       04:36:53               04:42:32             UttF                  (}4 : 38 : 00 to         04 : 39 : 00
                                                                                                                                             UHF                   04:41:00            to 04:43:00
                                                                                                                                            tIF                    I)4:36:00         to     04:45:00
     Eglin      .................                                                                04:39:00               04:42:52             UtIF                  04:39:00            to 04:43:30
                                                                                                                                             UttF                  04:40:30            to 04:44:30
     Canaveral                ..........                                                         04 : 40 : 52           04 : 42 : 55        HF                     04:33:30            to 04:42:30
                                                                                                                                            tIF                    04:35:15          to     04:35:30
     Canton         ..................                                    '......................

and the         retrofire                  times      necessary     lind inunediate                              the fly-by-wire             system  which utilizes                             the auto-
reentry      been required.          Following      tlmse trans-                                                 m_tic    COl_trol           jets.  Tiffs proc_edure                               was _us
missions,       which     were primarily        from ¢lle Ber-                                                  planned       so that a fixed att.itude            would be pro-
muda       site, the astronaut            made     the planned                                                  videxl for ntdar         tracking       and so that the astro-
cheeks     of all of the spacecraft             control     mMes                                                naut     could     make       the nece_;ary            l_l)()rls     and
using both the automatic               _md manual         pI_)por-                                              observations       during      the fil_ orbit,           l)uring      the
tional    systems.         All of these checks indicated                                                        ill'st, orbit, it was obvious            from the astronaut's
that all of the control            systems     were oper_ting                                                   repoi_t,s that      he could        establish      l lie pitch       and
satisfactorily.          Also,    the ast, ronaut        t_ported                                               yaw attitude         of the spacecraft            with l)lx_qsion
that he felt, no ill effects as a result, of going                                                              by using        the horizon          on both the light               and
from high accelerations              to weightlessness,        that                                             dark sides of tim earth,              and that he could al_
he felt he was in excellent            condition      and, as the                                               achieve       a rea,,_mable         yaw      reference.           Aside
two previous          astrona.uts     had commentM,            that                                              from     the xylo_         tal)let    taken     over Kano,            he
he was greatly           impressed       with the view from                                                     had his fil,',_t _md only food (tube of apl)lesauee                      )
this a_ltitude.                                                                                                 over Canton         Island       during     this orbit and re-
    The first orbit went exactly          as planned       and                                                  l)Otqe(1 no i)mblems           with eatin_ llor ally notice-
both    the astronaut        and the spacecraft,         per-                                                   al)le (liseomfol_s         following        the intake          of this
 formed    perfectly.      Over the Canary          Islands'                                                    food.
site, the astronaut's     air-to-ground      transmissions                                                          During  the first orbit, the network        radar sys-
were patched       to the voice network         and in tuml                                                     tems were able to ol>tain excellent       tracking     dat'_
to the Mereu W Control             Center   and provided                                                        and this data, together       with the data obtained
the control     center   and all other voice sites the                                                          at, cutoff, provided    vet 3, ac('urate     information
capability      of monitoring     the transmissions       to                                                    on the spacecraft    position    and orbit.      As an ex-
and from the spaeecr'tft       in real time.    This eon-                                                       alnl)le , Imtween the time the spacecraft                                        was in-
dition    existed  throughout    all three orbits from                                                          serted    into ort>it and the data   were                                       re(.eived
all sites having      voice to the control    center and                                                        from       the        Australian             siles,        the      retro_quence
provided      the bee?, tool for m,tintaining     sura, eil-                                                    times changed     a total of only                                  7 seconds     for
1,_nee of the flight.    (See appendix      A.)                                                                 relrofire a! the end of 3 orbits.                                  This indicated
   Except. for the control      systems checks wlfich                                                           the accuracy   of the                      orbit  l)arameters.                        From
were made Imri(ulieally,     the as't,ronaut remained                                                           this point to the end                      of the 3-orbit   flight,                   using
on the       automatic                      system       with     brief     periods                 on          all of the available                        radar    data,   these                    times

('hangedonly 2 _conds. The final retrose-                                      observe   tile earth   and horizon  while traveling
quence timewas04: 32: 38as('(mqmred        withtile                            in this direction     and to determine     his ability
time initially ('(mqmted ('u(ofl'of 04:32:47                                   to control.     Following   this maneuver,     the as-
andtile time initially setinto tile clockon tile                               trommt       t)egan    to have what  appeared     to be
groundbeforeliftofl' of 04:32: 2S. All of tile                                 trouble    with the ffyro reference    system, that is,
networksites              da.ta
               received fromthespacecraft                                      tile attitudes       as indicated by tlle spacecraft's
andmaintainedommunica!           ionswith theastro-                             instruments       did not a_ree with tile visual ref-
naut from llorizonto horizon,andeverything                                     erence    of the astronaut.          However,      the astro-
           ill                 n
l)rogressed a('olnpletely ormalfashion.Be-                                     mlut reported       he had no trouble       in maintaining
      o                 eond
cause f theexcellent itionof tlieastronaut                                     the proper      attitude     of tile spacecraft      when he
                   , therewasnoquest
andtlle Sltaeex'raft                      ionabout                             desired    to do so by using the visual reference.
continuing                     o
           intotile secondrbit, anda "go"de-                                    l_;eeause of the 1)roblenis          with tile ;mtomatic
cisionwasmadeamong                     at
                            personnel (hmymas,                                 control    system,     previously     mentioned,      and tile
Mexicoand the MercuryControl ('enter and                                       apparent     gyro t'eference      ln'oblem,   tile astronaut
"foremost"heastrolmut        himself.                                          was forced     to deviate    from tile flight plan to
   Shortlyafter tile t illle thg| the "go" decision                            some exlent,     but he was able to continue      all of
was made a! (_,uaymas,    the Slm('ecraft    began I_)                         tlle necessary    (tontro] systems   tasks _md cheeks
drift in right yaw.    After  illhnving   tile space-                          and to make a number of other l)reseribed           tests
craft to No through several cycles of drifting      in                          which    allowed     both  tile astronaut,   and     tile
yaw attitude        and then being       returned     by the                   ground       to evaluate          his    l)erformanee         and    the
lligh till'list jets, tim astronaut      reported     that he                  llerfonna.nce         of tile slla('ecraft     systems.       As ob-
had no 1-I)omld        jet action   in left yaw.        With                   _,rved       by tile ground           and the astronaut,          the
lUl astronaut      aboard    tile Sl)ace('raft,   this mal-                    horizon       scamlers       appe;tred     to deteriorate      when
function     was considered      a minor l)i'oblenl, e.,q)e-                   on the dark side of the earth;                     but w]len the
cially since lie still had eontr(ll        over the space-                     spat'el'raft       again came into (htylight             the refer-
craft   with a munber       of other available        control                  enee system            al>i)eared     to improve,        l[owever,
systems.     It should      tie pointed    out, however,                       amOyses         of tile dltla sul)se(luent          to the flight
tha.t, without    Jill i_stromult    aboard    tile space-                     l)roved       t.hat the horizon          scanner      system     was
craft, this problem      would have been very _rious                           functioning          llroperly     but the changes        ill space-
ill that ex(,essive    amounts     of fuel wouhl have                          m'a ft at t itudes t hat resulted           from t he maneuvers
lieen used;   and it may have been necessary       to                          l)erf(n'med    I)y the astronaut     caused tile errone-
reenter  tile Sl)ace('raft in sonm contingency    re-                          ous outputs       whi(.h lie notieexl on the attitude
covery area because of this high fuel-usage    rate.                           instruments,       it has been known       that Sl)urious
   During  tile pass over the control                           center   on    all itude outputs      wouht result if the gyro refer-
the second orbit, it was noticed that                          t,he telem-     ence system       were Mlowed      to remain    in effect
etry        <',hannel    u_(l   to     indicate       that     the     land-   (lurin V larg'e dea, iations   from the normal        orbit

ill/ bag was dephlyed            was showing       a readout                   attitude of 0 ° yaw, 0 ° roll and 34 ° I)itell, a.nd
which,     if true, indicated       that the ]an(lil_g-l)ag                    this was apl)arently     the ease during     tile 180 °
deployment          mechanisnl       had    tx, en actuated.                   y_tw maneuver        whieh   was  eondueted        over
                                                                               Africa.   This c,(mdition    will tie a llevi_text    in
IIowever,       because    there    was no indication        to
the Itstr()llallt   all(1 he had not rel)orted       bearing                   future    flights by allowing     tile astrollatlt    to dis-
any unusual        noises or noticing       any motions      of                ('omm('t. tile horizon     scanner slaving      systmn and
the heat shield, it; was felt that this signal, al-                            tile l)Vogvannned      precession    of the tyros which
                                                                               pre-'_erve,s tile hx'al horizon      to lie di_onneeted
thougtl     a l)roper     telemetry      (mti)ul , was false
and prol)al)ly       had resulte(t     from the failure      of                while he is maintaining      att.itudes              other   than    tJm
                                                                               normal  sl)acecraft   orl)it attitude.
the sensing switch.          (if course, th is event caused
a great deal of analysis           to result and later l,e-                      As tile go-no-go          point       at the end of tile second
quired  tile most           important           decision     of tile mis-      lind    t_ginning        of the     third    orbit      _q)proached,
sion to lie made.                                                              it wits determined     that although     some spacecraft
     Tile    fligilt    continued      witll      no further         serious   malfmmtions        had occurred,     the astronaut    con-
problems           and   the        astronaut        performed    the          tinued to be in excellent      condition    and had com-
l)bumed           180 ° yaw         maneuver         over Afric_t   to         plete    control    of    tile spacecraft.            He     was    told

by the Hawaiiansitethat the MercuryControl                                              aerodynamic     force    was exerted      to kee t) the
                   the       to
Centerhad made decision continue       into                                             shield on the spacecraft.      In addition,   based on
                              c         and
tile third orbit. The astronaut oncurred,                                               studies nmde in the past, it was felt that the re-
the decisionwasmadeto comlilete the three-                                              tention  of the package    would not cause any seri-
orbit       minion.                                                                     ous damage      to the heat shield or the sl)aceeraft
   One other problem   which caused some minor                                          dm'ing    the reAsntry     and would hurn off during
concern  was the increase   in inverter tempera-                                        the reentry    heat I)ulse.
tures to values somewhat     above those desired.                                           Also during    the pass over the Ilawaiian        site,
It appeared,    and the flight     test results    con-                                 the astronaut     went over h is retrosequence     check-
firmed,   that the cooling    system    for these in-                                   list and l)rei/ared       for the retrofire    maneuver.
verters  was not functioning.       However,    recent                                  It was agreed         that the flight    i>hm wouhl      be
                                                                                        followed     and that the retrofire    maneuver    would
tests made previous  to the flight had shown that
the inverters  could withstand     these and higher                                     take place using the automatic        control    system,
operating    temperatures.                                 The    results   of these    with the astronaut    l)rel/ared  to take over man-
tests caused    the flight                             control    people    to mini-    ually should a malfun('tion      occur.     Additional
                                                                                        time che<'ks were also ma(le over tIawaii       to make
mize this problem,                             and it was decided   that this
minor malfunction                              was not of sufficient magni-             sure that   the retrofire   clock was properly         set
tude to terminate     the fight   after the second or-                                  and synchronized       to provide      retrofire   at the
bit.    Furthermore,     a backup    inverter was still                                 proper    moment.     The astronaut        himself   con-
                                                                                        timmd to be in excellent      <'ondition     and showed
available    for use had one of the main inverters
failed           during                 the third    orbit.                             complete   confiden('e     in his ability to control                        any
                                                                                        situation  which might develop.
   During  the third orbit,       the al)l)arent   prob-
                                                                                            The retrofire     manuever      took place     at                   pre-
lems with the gyro reference         system continued
                                                                                        cisely the right       time over the California                          site
and the automa+ic   stabilization      and control   sys-
                                                                                        and, as a precautionary            measure,   the astronaut
tem        (ASCS)                       maJfunctions         in the yaw axis were
still       evident.                     However,          these problems    were       performed      manual     control     along with the auto-
                                                                                        matte control     during       this maneuver.       The atti-
not major    and                          both the ground           and the astro-
naut  considered                            that the entire          situation was      tudes   during    retrofire      were held within      about
                                                                                        3 ° of the nominal        attitudes      as a result of this
well under    control.                               This    was primarily      be-
cause of the excellent                              condition   of the astronaut        procedure,      but large amounts     of fuel were ex-
                                                                                        pended.       Following    this maneuver,    the astro-
and his ability to use visual references  on both
                                                                                        naut was      instructed  to retain  the retrol/ackage
the dark and light sides of the earth,    and the
                                                                                        during   reentry and was notified       that lie would
fact that most of the control  systems   were still
                                                                                        have to retract  the periscope      manually    and ini-
performing      perfectly.    The one t/roblem which
                                                                                        tiate the return to reentry   attitude    and the plan-
remained      outstanding    and unresolved     was the
                                                                                        ned roll rate because of this interruption        to the
determination        of whether   the heat-shield   de-
                                                                                        normal    spacecraft,         sequence of events.
ployment                  mechanism                   had      been   actuated  or
                                                                                           Following     the       firing of the retrorockets                       and
whether                the telemetry                 signal     was false due to a
                                                                                        with     subsequent       radar     track,     the     t_eal-time      com-
sensing            switch  failure.      During                      the pa.¢s over
Hawaii              on the third    orbit,   the                    astronaut   was     puters      gave      a predicted        landing            point.      The
asked to perform     some additional     checks on the                                  predictions  were within    a small    distance    of
landing-bag    deployment     system.    Although     the                               where the spacecraft  and astronaut    were finally
test results  were negative    and further    indicated                                 retrieved.  As far as the ground    was concerned,
that the sigqml was false, they were not conclu-                                        the reentry    into the earth's    atmosphere     was en-
sive.    There were still other possible      malfunc-                                  tirely  normal.      The    ionization     blackout    oc-
tions and the decision      was made at the control                                     curred   within    a few seconds       of the expected
center           that           the safest          path      to take   was to leqve    tiane and although      voice conmmnications         with
                                                                                        the astronaut      were lost for approximately            4
the retropackage   on following   retrofire.                                     This
decision   was made on the h,_sis that the                                     retro-   minutes      'rod '20 seconds,        the C-I)and             radar    milts
                                                                                        continued      to track      throughout              this     period        and
l)ackage   straps  attachexl to the spacecraft    and
the spacecraft    heat shield would    maintain    the                                  provided       some       confidence         that       all     was     well
heat shield in the closed position   until sufficient                                   throughout         the     high      healing          period.          As     it

        654401     0   -   62   -   b
might     be expected,     voice communications            l_e-   previous      to the time that. the drogue, (+httte     wtm
ceived from the astronaut          following     the ioniza-      deph)yed.        The rt+sults of these flight tests   htrve
lion blackout     period   resulted     ill a great sigh of       i,_(li('ate(l that so,,mwllat    different, control    pro-
relief within the Mercury         (?ore rol ('enter.     The      cedm'es lrc used (hu'i,_z this period for the          next
astronaut    continued     to report       that   he was in       flicht.
excellent   condition    after this time, lind the re-               The    conmmnications         with    the   astronaut
entry sequence      from this point on was entirely               during    the latler sta_'es of descent      on both the
noyllla].                                                         drogue    and main    parachutes     were excellent   and
   .k number       of spacec_raft       cx)ntro]    problems      allowed    (-omnmni(.ations      with either   the astro-
were experienced         following      l)eak    r_ntry     ac-   mint or lhe recovery      forces throughout      this en-
celeration    l)rimarily     be('au_    of the method        of   tire descent   phase and the recovery       operations
control    used during       this pe.riod.     In addition,       which look place following         the landing.        The
large    _mmunts     of fuel from        Ix)th the manual         landing    occurred    at 2:43 l).m.e.s.t,       after    4
a n(t automat ic systems has been used and finally                hours, 55 mimlles,    and 23 _('on(ls of flight.       The
resulted    in fuel del)le.tion      of both systems       just   recovery   operations    are described   in l).tper 7.

                                        7.    RECOVERY                 OPERATIONS

       By ROBERT F. THOMPSON,  Flight Operations   Division, NASA Manned Spacecra/t                                                  Center;            and
            ENOCH M. JONES, Flight Operations    Division,   NASA Manned Spacecra/t                                                  Center

                          Summary                                      cial vehicles--are      provided       by the Deparlment
                                                                       of Defend,      and for the most part repi_nt              op-
   Astronaut      Glenn and his spacecraft       were re-
                                                                       erational    units   that. devote         only a relatively
covered by the destroyer        USS Noa in tile North
                                                                       small part of their total workload                to Mercury
Atlantic     planned   recove D' area after      a flight
                                                                       recovery.      Recovery     te(,hniques      :lnd equipment
of three orbits around      the earth.     A description
                                                                       have been developed         which pemnit the Dep_rt-
of the events occurring        ill this recovery   opera-
                                                                       ment of Defense       to supImrt        this program      with
lion and a general       description    of the scope of
                                                                       an aeeept,_ble      diversion        from      their   normal
recovery   support   required     for the MA-6         flight
                                                                       fmmt ions.
are presented.     Also, the composition           and de-
ployment    of the recovery        forces provided         for
                                                                                   Deployment                   of       Support              Forces
various  landing   situations     are outlined     and the
location   and retrieval      techniques     available       to           In order to deN.l'ibe tile recovery        support    pro-
these forces are (lisc, ussed.                                         vided    for the MA-6      flight, recovery       areas ate
                                                                       considered      in two broad      categories:      Planned
                                                                       recovery    areas in which the probal)ility         of land-
   This l)aper presents   a general    de_'rit)tion             of     ing was eonsi(tered     sufficiently    high to require
the total scope of recovery   supl)ort   providexl             for     the positioning     of location     and retrieval      units
the MA-6       flight, briefly      describes   tile location          assuring    recovery      within     a specific   time;    and
and retriewtl        teclmiques      available     ill various         contingency      recovery     alias    ill which the l)rob-
landing    sitmttions,      and de,,_'ribes _he MA I re-               ability   of landing       was considered        sufficiently
covery operation         in the actual landing        area.            low to require     only the utilization       of specialized
   Recovery      operations      are defined     as the SUl)-          _arch    and rescue procedures.
port required       for location      and relrieval       of the          The planned       recovery      areas were all located
astrommt     and space(:raft       subsequent     to landing.           in the North Atlantic        Ocean as shown in figure
Before     the MA-6         recovery    is (lis('ussed     specifi-    7-1, and table 7-I is a summary      of the support
cally, two general           points are noted.         The sup-        positioned   in these areas at launch time for the
iiort, l)rovided      for all Mercury        flights reflects :_       MA -6 fl iglut.
eonsiderat     ion of both nOl'nm] flights and various
possible     abort, situations;        and it is the latter                       80 °                  60':'            40 °                 20'
case, that      is, supporting        possible      abort    situa-                I                     ]                 I                   I
tions having        a rm_sonable      probability       of occur-       r,,,,                    /-CAPE CANAVERAL                  AZORES                     ..440 o
 ring, that imposes by far the greatest                   support       " _                 /:       _-BERMUDA                        _ ".
                                                                                        /                    A
                                                                                                     \.__..-L_                 s
 requirements       on recovery      forces.     Consequently,
 while a relatively         large number       of recovery       ve-
 hicles and personnel          are required      to provide the
                                                                       20"--                //'q_.._ PUERTO          _                   _                    --20"
 desired    support      capability,    only _Lfew _rctually
any given
                          involved     in the recovery           for
                                                                        o. ";:
                                                                         °         I                "     I                I                   I \
   Secondly,     the re('overy      forces    which    have
                                                                                  80,                   60 °             40 °                 20 °
supported      Project    Mercury    flight operations--
the airplanes,     ships, helicopters,     and other spe-                       FIGURE           7-1.--MA-6      planned           recovery          areas.

   Specialreeoverv teams milizin_zhelicopters,                     port  was planned        for contingelmy     recovery;
amphil)iousvehicles, nd salvageships were                          however,   a large    force is required    because     of
located tile launchsite to providerapid ac-                        the extensive     areas     covered   in three orbits
cessto tlle spacecraftor landingsresulting                         aroun(l       l lm earth.           Tim l(x'ation              of contingency
from possibile abortsdurin¢ the late count-                        recovery   uMts for the MA-6    flight                                 is shown     in
down and tim ear]y l)]la_ of powered   fligllt.                    figure 7 -o.  A typical unit consists                                 basically     of
Winds at the launchsite weremeasurednd    a                        lwo      search    aircraft       specially    equipped      for
tile locusof probablelanding positionsfor                          l" I { F/I)F                on
                                                                                   horn in (/_' Slm('ecraft      beacons,   point-
various aborttinleswerecomputed facilitate
                                 to                                to-point       and    ground-to-air         eomnmnieations_
positioning of these recovery    forces.                           and parares('ue         1)el.'sonnel equil)l)ed     to provide
   Areas A to E supported    all probable             landings     on-scene assistance         on both land and water.          No
in the event an aboI_, was necessitated                  at any    retrieval   forces     were deployed        in support     of
time during        1)owered      flight.    Area A would           contingency     b/ridings:    i)roeedures     were avails-
contain   landings     for a/n)rt vehx'it ies up to about.         Me for retrieval        support       for after   the fact.
21,00(I feet per second, and Areas             P,, (',   D, and    These search fllld reseile      tlllits were stationed     at
E would supl)ort         higher     M)ort velocities       where   tim     16 h)eations           shown              in figure       7-2,and         were
programed       use of the retroroekets           t)eeome ef-      all linked by communications                 with tile recovery
fective   in localizing      tile hmdiug      area.       Forces   control center at ('ape ('anaveral.                Throughout
its shown in table 7-I were positioned                  in these   the MA-6 flight, the astronaut                 wqs ('ontilmal]y
areas   to provide         for ]o('alion      and      retrieval   l)rovi(led      with retrofiring         times for landing        ill
witMn     a lnaxilnun),     of 3 ]).+)tit's in the areas of        fa.vorable        contingency        recovery    areas.     How-
higher   landing    i)rol)al)ility and (; hout_s in tile           ever, (lie contingency             forces deployed       had the
areas  where     the 1)robal)ility    of landing    was            (.al)ability       of flying     to any l)oint        along     the
somewhat     lower.                                                orbital      traek    if required.
   Once   tile spacecraft was in ort)itM     flight,
Areas   F, G, 'rod II were available  for landing                                        Recovery                Techniques
at the end of the first, seeon(t, or dfird orbits,
                                                                      In order    to complete   the                           description   of the
respectively.         Forces    as shown        in table    7-I
                                                                   recovery    forces  that   were                            deployed    for the
were available         to assure location       and retrieval
                                                                   MA-6 flight, it is important,                               to have It generM
within a maximum           of 3 hours      for most   probable
                                                                   understanding                 of the techniques                           that,  were
landing  sit uatious.                                              available    for           location and retrieval                         in various
   Tiros,    to assure      short-time   re(.overy for all         situat ions.
1)robalile    at)otis   that eouhl occur during       pow-                                               Location
ered fligllt     i).nd for landings    at the end of e'wl).
of the three orbits, a totM of 21 shil)s, 12 heli-                    Launch-site     forces are expected     lo have vis-
copters,  and 16 mar(q), aircraft     were (m station              ual contact    with the sI)aeeeraft   should an abort
                                                                   occur   in their    area.  Launches     are scheduled
in the (leep-water  landing    areas at the time of
the MA-6 laun('h.     Fhwku l) searclt aircraft   were             after      daylight       in the launch   area and satisfac-
ava.ilal)le   at several   staging     locations     to assure     tory      weather      is assured   before launching.     The
maintaining      the airborne     aircraft     listed in table
7-I.     These forces in the planned          recovery   areas
were all linked        by communications             with the
recovery         control    center   loeale,l within         the     i       _                _
                                                                                                   .zo. s Rl lg/"!
                                                                                                  BE             _

Mercury        ('ont rol ('enter   at ('ape Canaveral.
                                                                     ,'_/f_'_.__.'_..                                           __
                                                                                                                               __.               A
                                                                                                                                             W.AJ LElN_
      Since   it was recognized     that   eertahl    low prob-
ability       situations      could  lead to _ spacecraft
landing          at essentially     any   point  along    tile
ground         track    over wM('h the spacecraft      flies,
suitable       recovery     plans and support   forces were
                                                                         160                       40            0       40       80         120     160
 provided  to rover this unlikely contingency.       In
 keeping  with the h)w probabilities       n_sociated               FI{_UR_      7-2.--MA-6            staring        h_.ations        for   contingency
 with remote landings,    a minimum     type of sup-                                                     recovery.

launch-siterecovery            is
                    commander airbornein                                   niques   or modes       of Ol)eration    available              for
a helicopter ehindthe launchpadat the time                                 adapting   to different    possil)le situations.           It     is
of htunch, imother lamwh-type support forces                               beyond     the _ol)e     of this discussion       of MA-6
are     l)rebriefed      and deployed      where possit)le                 recovery     ol)eralions   to describe     all of the vari-
aborts      could    t)e effectively   observed  and re-                   ous cal)al)ilit ies invol vet1, and only limited com-
trieval     assiffnments    executed.                                      ments are made in order           to l)rovide     a general
    hi the dcel)-water        areas of the North  Atlan-                   feeling   of what retrieval      SUl)l)(>rt was available
                                                                            at the tin,e of the MA (; launch.
tic:, search aircraft are airborne                 in the recovery
areas prior to spacecraft   fly-over               or landing'.    If         All recovery   ships have the basic capability
required,    the aircraft    would           be directed tow'lrd           of hoist ing the Mercury     spacecraft    clear of the
a search     datum    established            from landing-pre-             water an(t securing    it on deck.    Basic l)lans call
diction     information        provided      by the Mercury                for tile astromlU[      to remain    in lhe sl)acecraft
trackinK-comlnllinK           network       and other space-               until it, is aboard    shi 1) and e_zre,_s at this time;
craft    location     systems;      such as, St)FAR,           lhe         however,       he could effre_s fr<)m the sl)aeeeraft
sound tixinff and ran_rin K system which utilizes                          prior       to pickup    if this   procedure      l_ecame
an mMerwater           detonalion      technique,      and IIF/            desiral)le.
I)F     (high     frequency/direction           fintting),     the             The helit'ol)tel.'s     whi('h   were in the launch
tixin(g" of spacecraft        position     by land-based      sta-         site and in each <)f the end-of-orbit,              landhag
tions utilizing       IIF radio sigmlls radiated            from           areas    have three       techniques     available    for re-
the spacecraft         subsequent        to landing.       At'cu-          trieval.    They      are: (tel)loymen[       of a flotation
racy of the (lalmn     is exl)ected            to t)e sufficient to        collar and retrieval   of the ast rommt only, simul-
t)rinff these airborne     search             aircraft   equil)pe(1        t ane<ms re[ rieval of the ,si rommt and the space-
                                                                           <'raft with transfer   of the astronaut  to tile heli-
with special elect tonic receivers            within range of
spacecraft        ele('troni<'    be'wons   operating    in the            copter,   and      simultaneous    retrieval      of    the
UIIF       (ultra       high    frequency)     range.    VChen             astronaut   and tim spacecraft    with the astronaut
within     I'tlF,/I)F        range, the search aircraft      can           remainin K in the Sl)a('ecraft.         Only    the first
('ommen('e         "hominf"        (m the sl)acecraft      elec-           case is dis('ussed    since this method      of retrieval
tronic     beae<ms         m_til visual    eont'wt    is estab-            was l)lanne<l as the       I)rimary    technique     for        use
 lishe(I.    Fluorescein         sea marker        'm<l a flashing         t)y heli<'ol)ters had       they    become     involved          in
light  are   l),'ori(le(1  as visual    location   aids.                   MA (;. Two swimmers               are del>l%'ed    into the
I_ookouts ale(mr(1 the recorery      ships are also on                     water    tronl   the relrieval       helicol)ter and tlley
alert during     the reenlry  and lan(lin_z I)hase in                      affix a floia( ion c<)llar to the spacecraft      as shown
an art eml)t to sight the sl)aceerafI.                                     in figure 7 3. This         collar is positioned       about
  I n con[ ingem'y areas, procedures                     utilized  for
MA (; called for the search ilireraft                       to remain
on tile ground      in an "alelq."      stares.    In the
event of a contingency      landing,       a se_,u-eh area
would   be established    by the recovery          control
center  front information      sinlilar     to that used
 in the phumed      areas for establishing           the search
 datum.       Contingency           aircraft        were      Mso
 e/lUil)l>ed with 171IF/I)F        equipment        coml)atible
 with spa<'e<'raf/    beacons     and would utilize           this
 equil)ment      to locale       the     spae_rafl.          This
 "Izround    alert"    I)r(r('e<lure assured         maximum
 utilization    of all aircraft        and still permitted
 reachin_r    all   l)o_sible      landing     sites      well   within
 tile life[ ime of spacecraft           location       aids.


    Re_'overy  units         del)loyed         to l)rovi(le       a re-
 trieval calmMlity          _enerally         h:tve several        teeh-        FmURE 7-3.--I:Ielicopter    retrieval   technique.

                                                                                                                    GR, TRACK                                                                                                           O                    50
                                                                                                                                                HF/DF                               , SEARCH                                               ,L_L_/__.
                                                                                                           N. LAT.                       _FIX                 NO I,                 , AIRCRAFT                                                _.MI
                                                                                                             22°-                              __                                   ,                      • DESTROYER
                                                                                                                          CALCULATED_                                     '     i                              SOFAR                 FIX
                                                                                                                          LANDING                                _,_            '
                                                                                                                          POINT ._ID                                      _                                   , TELEMETRY                      AIRCRAFT
                                                                                                                          SEARCH'_)ATUM                              ._'_....                            li    >          CARRIER

                                                                                                             21°-         HF/DF FIX NO. 2 -                                     '              .l_._._..                             DESTROYER
                                                                                                                             SPACECRAFT                                                        "-
                                                                                                                                  LANDING               AND                                                         i
                                                                                                                                  RECOVEIRY                     -              = TELEMETRY'
                                                                                                                                                                                        AIRCRAFT                              SEARCH
                                                                                                            20 °-                                                                                                             AIRCRAFT

                                                                                                                    W. LONG. 7C7                                     6'9 °                           6'8°                      6'7 °                    6'6o

                                                                                                                                    FIGURE                7-5.--MA-6                              landing"                    area.

                                                                                                          ]<waled                   al,out             4l)          iuiui       ical miles                              d<Jwliran_e,    and
                                                                                                          a second desii'oyer                                                 was Iocitled                               al)oui 40 ]iittlti-
                                                                                                          cal lniles iipi'aii_+e.                                              Telenieirv                                :)lid search air-
                                                                                                          Cl';ifl                 were            tih'horiie                            ill       lira             tlrett+              sis        shown.

                                                                                                          Afier                   )lie        rt,trorot.kei                              lii:tlipllVel,                        alld          :ii)Oill              1D
     FIGURE      7--1.--()ii-sC(,lie                as:,4istillic_,       Io     colltinlzency            Iliillllles                 I)rior            io liie esliinliied                                       lime of ]alidin_z,
                                  tl|ndill_         on     wHlt.,['.                                      tlie          l'ec<)Vel'V                   c())il         tel            ceiiier                   liOl itied tilt, i'e<'ov-
                                                                                                          ei'y           forces                thiit            acc<>r_lhi_"                             l<J        calcuitiiioiis,                            lhe
the     spacecraft               [_efore            inflation:             and         when         the   lniitlili_Z            In'crib.ted
                                                                                                                                         was     to oecilr      near   the  tip-
dual rin_s        are    inflated,       the spacecraft,       is par-                                    I'ali_'l_ deslrover         :i_, ,,.;howii in   lilZure ]" ,.     The
tially supported           and, rehltive          to the spacecraft,                                      a_,tr()ll;llll,     was also i)rovided              witii   tills   in-
becomes a very stable working- phil form.                        After                                    forlnalion          llv lhe ][ei'l'llrV      (_<)llll'O] ('enter     as
colhu'     installation,           /lie aslronaut        can                                      S<)Oll              its         coliiliilllliC:tl                             hms                were                  reeslaldished
either th,'ou_h        lhe tower as shown ill fiKure 7-3                                                  filler             lht,         +p:l<,ecrnt'l                             eliler_xed                     frlnti              ihe          ioniza-
or ihrou/h         lhe    side      halch     for transfer      to the                                    tion            h]ack()ul.                           ],lilll,;lillls                    alJolu'd                    tile         I'SS              .You,
helh'opter      by persoimel            hoisl.                                                            klle          di'Sll'())'e]'                  ill         lhe             llpi'ali_'e                    })ositiol/,                    siKhted
    The flotation         collar       is also utilized       in pro-                                     l]le          Illaill           }lal'achllle                         of             1}le       ,,-4pace('l'aft                      as        }!        de-
riding     e_mting'ency          ,'ecovery      forces with :tn on-                                       set,tiller|                 })eiow              ;I I)l'ol¢.eli                       (']()ti(1            ]a_'er              aft       all        alti-
scene assistance            Calmbility          for remote       water                                    tilde            of         :tl.lOlll               5,(1(1()              feet             fl'Oill             ;I     I'aliae             of         ap-
landinKs.     This niode <ff operation     is depioie<l                                                   ln'oxhnlileiy                              5 ilalllh'al                          miles.                  ('onimunieations
in fiKure 7-4 which shows pararescue         personnel                                                    vcel'e esl;tl)lishell     })el weell the stlii,'ecl'ii fi IInd tile
at the spacecraft   following  their delfloymeni       by                                                 des) I'()_'el', :)lid :l conl ill)lOllS flow of liiforlilal    ion
parachute    from a c<mtin_zency search aircraft.                                                         was passed ihrouKhout                 lhe reinahider        of the
   This discussion     of the re_'overy   forces    that                                                  Ftq'O%'el'?,"  oiiel'lil i<)]i.
were deployed   and the brief rgsun,6 of the pro-                                                                  In       iilis         case,                ]o,'ali()ii                      WaS                Vlq'y             sll'a]l£lllfoi'-
cedures io t_ utilized fro' location and r_trieva]                                                        ward hi thal a )'el rieva]                                                          ,_]iip Kained visual COli-
 in various          sit uaiions     l>rovide a back_zr<)und                                        for   im't dllrin K _-pucecrafi                                                           ]aildin K. t[owevei',  sis
describin_z            the     actual     *IA _; h.'aiion                                          and    ;I Iliallel'                   of       inleresl                     t'l')l'         fllllll'e                operalions                       sitiee
retrieval.                                                                                                visual                   siglililiTS                       :Ire                i>rolml4y                            lhe           exceptioli

                                                                                                          ralher                  l lian          liie          ru]e, oilier                               spltceeraft                         lee:ilion
              Description                     of     MA-6               Recovery                          ilifOl'llialiOll                            nvaiialile                              SOOll             Itflel'                ]altd]l/K                     is
                                                                                                          also plolied                          hi       [iKui'e                    7-5.              The SOFAI{                                   fix was
     Recovery           forces            in :ill areas                 were       notified          of
                                                                                                          al)l)roxhii:llelv                                   _-nautical                             nil]es               froni             lhe         ]and-
mission     progress    by lhe recovery    control                                          center.
                                                                                                          in K          l)oilll,              ;unl        l]le            [il'Sl              two             IIF/I)F                      fixes         were
('onseqttently,      units located    :it /he end                                           of the
                                                                                                          wilhin     :il)l)roxiimllely :2.> ini]es of lhe ai'iua]
third       orbit     knew             they         were        to hecolue             involved,
                                                                                                          sl)aceci'afi l)<)sil ion. This ]an(lhi_ infornmtion,
and     figure        7-5       presents                 recovery              details           in the
                                                                                                          a](ilUZ             wil]l            llw            (':i]('ulaled                       lan(lin_"                     p()sili()n                   ])ro-
MA-(;         landing           area.              An       aircraft            carrier           with    vhled               1Lv the                Mercury                            ]lelwork,                        WOll]d               have                as-
retrieval           helicopters                    was      lo('ate(1          in the        center       sured             ])l>ili_'iii}.t " $elu'eli :ih'ernfl within I'ttFI
of the        1)]anned          htndinK               area,           one destroyer                was    I)F            I'ali_ze.       In fuel, llie ah'l_)i'ne searcli air-

                                                                                                                                                                              •        ! N/,L                            PA_: _"
                                                                                                                                     _iL_CK                         AND                       V;'H TE                                          -,
                                                                                                                                                                                                                              P_.'CJT_6bP, AF_._
                                                               FIGUr[,;.    7-6.   MA-6         retrieval   by     (leslrc,yer    USS     Yr,r.

('raft   ill the      MA-6       landing   area   ol)t;tined                                                ;ts shown    i_ fiTm'e 7 6. A deck wim:h is used
[71[F/1)F     ('otlt;tct    with the Sl)a('ecraft    shortly                                                for i_dmulit_z      |he lifli_g          lit_e_ and when the
after    beacon       activation      at m;til_ I);tr_tchule                                                Sl);tcecraf|  is l)rol>erlv      l),)sit (oiled vet! i('allb' _ the
()l)e_itl_';           h,,wevev,              i! was the .V<_,'._.da) _ :ll_(l she                          (htvit is rotated      i_d,);tr(l     to p,),_ition the space-
','_'_.S f)ll   hel'     wlly       to     i't, ll'it_ve.
                                                                                                            craft ()_ deck.       A h_'a('e ;_l|a(.hed         to the davit
   "Fh(_ No,               ha(l the Sl)acecraft                            .d)o:trd 2_ mil_-                is h_were(1 over             _he top of the Sl>a('ecraft                  t(, [)re-
utes after                 htlldin_z.   Figure                             7-(; shows   the                 vehl ,swit_i_               Ol_Ce the Sl)a,'ecraft            is clear      of the
Sl);t('e<'rafl     ;ts it is t>ein/ lowered        t(> the deck.                                            W_ll    el'.

A.stvolmul         (;lenll  rein:titled      iu the Sl);tce('r;tft                                                 i+;a('h ship         iz_ |he       recovery         force      had      em-
(luriJ_      IJickul>: alid aftel' it was l>(>sitione(l ()rl                                                barked a sl)ecial me(lic;d |e;zm c<)_sistizzg of two
the shil)'S deck, he egrcsse(l            fronl the sl)a('e('rafl                                           d,,('_()_',_ aml <>_, teclH_icia*_ 1o l)_'ovide medical
through         the ,_i(le h;ttc]_.      ()riTimtl    l)Ialls had                                           (':t_'e aml/,)v         initial        ])os|ili_h|       medical         dehrief-
called for egress through               the to 1) ;it this time:                                            i_.            For   the MA-_;         mission,        l)(,:Iflight      medical
h(>wcveF_              i]l(_    ;Is|Ir()llllll|             a.V;IS   l)e('omi]lg       [lll('Olll-
                                                                                                            (h.l,riefi_"          was     the      only      re(luirement         ;t_<] was
fort;d)ly              warm              ;iHd       dec(fled           !o     le_tve   by            the
                                                                                                            (.Oml)]eled          (_nb<);(r([ the          .Vo:+ in ;tbon!            :2 hou_
easier e/tess         l)ath.
                                                                                                            after  I)ickul ). The aslroH:tut                           was then         trans-
      In makit/g         !he ])i<'kul) _ !he :_'o:_ maneuvered
                                                                                                            feH'ed to the ;(ir,'_'afi ('aH'ier                      for fur|her         trans-
alongside       the Sl)acecr;tf!              and e_g:t/ed        ;_ h,x)k
                                                                                                            fer      to (;_'a_d     Tu_'k         IslaH,l.       at_d he arrived         there
hHo the sl)acecraft's             ]iftin_        ]ooI).    The hool_ is
 vig_'ed o]_ the end of ;t (leta('h:dde                 l),)le 1o fitcili-                                  al)l)r,)xim;_|el.v      .') hours    af|ev               landing.     Addi-
|;ICe    (]]iS (,llg;lg('llitqll       ;ill(|    lhe lifting       liz_e is                                 ti,,n:tl e_giHeeriHg         :_n<l medic:d               dehvieiin_zs were
 _'i_g(.<l over ()m. of (he shil)'S regular                  bo;tt (h::its                                  c,,l_,h|c|ed     a( (;rand Tul'k.


                               ORIGINAL                      F'AS'_--
   BI._CK               AND              WHITE                 PHOTOG"RAPH
                                     TABLE    7--I.---_iL't-6                 Recovery                     Force,_'.for              the     Planned          lfecocery                    Area,s'

                                                                              Number                of                     Numb(,r        of                                                                         Maximum
                                   Ar,'a                                         search                                    h(,licol)t,,rs                     Numb(,r                     of ships                   ]'_,cov(.ry
                                                                                aircraft                                                                                                                              time,     hr

     Launch             site   ............                     ...........                                       . 3 ......                             ................                                                    Short
     A .....................                                          6       ............                       ,'_ .........                           ,_ d_,stroyers                      ....                            3 to    6
     B,C,          D,      E ..........                               l('ach            ................                                               I 1 destroyer      oach                      .....        !           3 to    6
                                                                                                                                                         I carrier   each
                                                                                                                                                                                .......                                         3

      ",      ', H ............                                       2 (,ach           .......                     3 each           .....
                                                                                                                                                         2 d(,strovers                      each      ....
                                                                                                                                                         21    ..............                                /       ........

                    T_tal_-_T                     __    _--           16 ...........                                 12          ........                                                                    /

8.       AEROMEDICAL                                         PREPARATION                         AND RESULTS                          OF          POSTFLIGHT
                                                               MEDICAL                       EXAMINATIONS

By HOWARD A. MINNERS, M.D., Li]e Systems       Division,   NASA  Manned Spacecra]t Center; WILLIAM K.
    DOU(;LAS, M.D., Astronaut  Flight Surgeon, NASA Manned Spacecra]t Center; EDWARD C. KNOBLOCK,
    Ph. D., Walter Reed Army Institute o/Research;       ASHTON GRAYBIEL, M.D., USN School o/Aviation
    Medicine, Pensacola, Fla; and WILLARD n. HAWKINS, M.D., O_ce o/the Surgeon General, Hq. USAF,
         Washington,              D.C.

                                      Summary                                                         (2) Detailed          preflight  clinical    evalua.tions
                                                                                                   conducted   prior        to the canceled     and successful
    Tile preflight    and                    postflight  medical                 evalua-           missions.
tions   have    revealed                      no adverse    effect                of 41/_
                                                                                                      (3)      Immediate          preflight        examinat,   ion   con-
hours of space flight                     per se.              In all effort to in-                ducted       on l'mnch       lnorning.
terpret such normal                        results,           three   alternatives
                                                                                                      (4) Postflight      medical examinations                   aboard
come to mind:
                                                                                                   the recovery    ships and at. _he Grank                     Turk   Is-
    (1) As me,lsm'ed                      by available                 techniques            of
                                                                                                   brad medicM      facility.
examination,    space                     flight  has,                indeed,    no          ill
effect.                                                                                                             Preflight        Examinations
     ('2)     The          effects      of      space         flight      may         be     so
                                                                                                      The pilot's    general    pi,eflight    activities,    com-
evanescent             that  they were resolved    before                                   the
                                                                                                   nlencing    with t)reparation        for a planned        early
pilot could             be examined   after the flight.
                                                                                                   ,Ianuary    1962 hulnch,     ;u'e summarized           in table
     (3)      The MA-6                space         flight    was of insufficient
                                                                                                   8-I.    Throughou.t     this period,     his physic'd       and
duration            to produce               detectable             effects     or     such        mental    health    remained      excellent.
effects      have not yet become                        evident.                                     Lift-off  marks  the simultaneous     culmination
   Further     study in future manned     space flights                                            of a number    of different  countdowns     used for
should     help to determine    which     of the_,     or                                          such    "L complex         mission.     The    aeromedical
other, possible interpretations    is correct.                                                     countdown      rel)resents     an effort not only to af-
                                                                                                   ford the pilot sufficient         time for sleep 'rod im-
                                                                                                   mediate    preparation       for the mission,       but also
     Comprehensive                    medical          evahlations            of Astro-            seeks to insert      him into the spacecraft           at the
                                                                                                   time required        [)y the other      countdowns.        By
naut        John      H. Glenn,              Jr.,      were performed                 prior
                                                                                                   careful   planning      of aeromedical       countdown
to his orbital               space      flight         and     as soon        after        this
                                                                                                   events, the pilot can be maintained        in optimum
flight        as     recovery            practices             permitted.              Pri-
                                                                                                   condition  and embarks      on the flight with a min-
marily,            these     examinations                    were      acc_omplished
                                                                                                   imum of fatig,e       and in tile best l)hysical     con-
to determine                the      pilot's         state    of health          and        his
                                                                                                   dition.   Significant     MA-6    aeromedical      count-
medical             fitness    for        flight.            In addition,     such                 down events      are listed in table 8-II.       A total
clinical           evaluations            serve            as baseline    medical
                                                                                                   of 7 hours    and 27 minutes        elapsed   I)etween
data     which              may   be correlated     with    inflight                               awakening   the pilot and lift-off:     he did not get
l)hysiological              information.                                                           to sleep again   until 23 hours      and 1{) minutes
   Aeromedical                data sources utilized    to _tablish                                 after heinz awakened    at '2:20 a.m.e.s.t,     on the
Astronaut              Glenn's          state         of     health      are:                      morning       of the flight. Therefore,                on flight day
   (1) Prior   medical     examination                                  commencing                 the pilot     spent more than 5 hours                on the ground
with astronaut   selection    in 1959.                                                             for every      hour   in space       flight.

 TABLE8--[.--MA-6                             Pit,_t'._         Preflight               Actiritie_

               I )ate                                        :\ctivity        i


       13,     15, "rod        16    Simulated             orbital         mission


                 15                  Flight          acceptance                   composite
                                        test,  launch       pad
          16 and         18          Simulated      orbital     mission
                 17                  Launch                simulation,                  launch
                                        pad;        network          simulation
                 19                  Lamich          simulation
         20 and         23           Simulated             flight,       launch         pad
                 22                  Full        mission         simulation;                  spe-
                                         cialists     medical            exanfinations,
                 27                  Preflight        physical            examination,
                                         countdown,              hmnch            pad    i can-
                                         celed      flight

                                                                                                                                    FmURE          8-1.--Balance                     test.
                                                                                                          (}lenn's             routiim        s('(,res             on these           rai]s           are eonsi(|-
             7 and      8            Simulated             launch         aborts                          erably           higher        than              those         which               h;Ive been ob-
            9 and       13           Mercury          orbital        sinmlation                           tained           frolll     it groll])              of    flight         persoiille].                 Also,
                 12                  Specialists             medical              examina-
                                        tions,       hospital                                             TABLE 8-1I.                    Significant                    Events         Prior              to Launch
                 15                  Insertion       s
                 17                  Launch         simulation                                                           1)hte                    _.s. (.                                    Ev(,ii       t
                20                  Actual          MA-6         flight

                                                                                                                   February                       a.ill.                 Began          low        residue
     In       Cape      Canaveral                 procedures               trainer,              unless
                                                                                                                    16,    1962                                              diet
otherwise       stated.

                                                                                                                   February               9:30        I). in.            Retired             i
     I)etailed               me(li(.al        examitliitions                       were          con-
                                                                                                                   19,     1962
dueled   l)rior to the ('ance]ed   flight in Jaimary
1962 an([ before llie flight in Fel)ruary.    Asl)e(.ls                                                            February               2:20        a.m.               Awakened                  aild

of the exiunination    wlii('h were noi time ('riti(':ll                                                           20,     1962                                             showered
                                                                                                                                          2:50        a.ui.              Breakfast
wero conlpleted          several    days 1)efore the Iaunc]l                                                                              a :05,              Physical                examina-
and inehlded         the following:        sl)ecialists'     ewlhla-                                                                                                        tion
lions     in neurology,          ophlhalniolotzy,           aviation                                                                      4:28       a,ill.              Suiting         started
                                                                                                                                          5:05               Entered          transfer
niedieine,     l)sy(.hiat Lv, an(I radiology;            a standar(I
12-lead     electroeardiograin,           an au(liotzram        , and
                                                                                                                                          5:20               Arrived             at    laulich
an     electroencephalograni;               and       bi(x'hemic;d
                                                                                                                                                                             pad    and            remairied
studies of blood aim urine.                All of tlie_ evahl-                                                                                                               in transfer              wm
at ions showe.d normal            results     and _vealed            no                                                                                                  Ascended                  gantry
                                                                                                                                                                         Insertion                into space-
('hange        froni the muuerous                          pre<'e(liu_              examiml-
dons.          In addition, special                        labyrinthine                studies
                                                                                                                                          6:25       a.m.                Couilt       dowli           resumed

were performed      in which the 1)ilot was timed                                                                                         9:47       a.ln.               L'tunch

and _ored <)n his ability t(> maintaiu       his balance
while walking    along su<'cessive|y       more narrow
                                                                                                             i Obtained             4 hours          "tnd          50   nlinutes             of     dozing,      light
rails 'is depicted     in figure     t_-l.    Astronaut                                                   sleep.          No     medication            administered.

h is auditory     canals wet.(, irrigated    for 45 _,¢'onds                                                                               and     there   was no                             c<)stovertebral angle  nor
with    <'areftdly      temperatm'e-re_baed           water,                                                                               bladder     ten<lerness.                           Skin was clear" and a cur-
and the warmest            teml>eratm'e     at which     tine                                                                              sory neurologic                    examim_tion                        was normal.                        Some
nysh_mus        l_,_an was recorded       as the threshohl                                                                                 of these          fin<lin/s,   along   with                                  extremity    meas-
t elilpeFaHIT'e.                                                                                                                           urements,            are listed    in table                                  S-III.    The au-
   The pilot   was again       examined      on l.umch                                                                                     thm=s have taken         the liberty      of summarizing
nmrnin_  by spe<'ialisls   in aviat ion medicine    and                                                                                    |he clinical    findings    of l)r. Myron, Neurologist,
internal  medicine.      This   examimttion,     begun                                                                                      I)r. (3ark,   ()pllthahnologist,       l)r. Ruff', Psy<.hi-
at '_ :05 a.m.e.s.t,   on February    :_<), 19(;2 (the day                                                                                 atrist,   trod l)rs. M('Iver       'rod Mullin,    recovery
of the flight),      revealed    a calm,     healthy,  an<l                                                                                forces physici,ms.
alert "MMt male.         Vital si_'ns were as follows:
pulse, 6S heats per minute            and regular;       blood                                                                                                   Postflight                    Examinations
pressure      118/80     mm lIg     (lef|,   arm sitting);
respiration       14 |>reaths per mimlte;       oral temper-                                                                                   Postflight       medical      evaluation     began     when
ature,     9fi.2 ° F;      and rome      weight     with    the                                                                            Astronaut        Glenn emerged          from the spacecraft
bladder     empty      171 p<mnds 7 ounces.        Eyes, eat.'s,                                                                           on board       tim destroyer         Nort 39 rot,rotes     after
nose, and throat           were normal     and mwhanged                                                                                    landing.       The l)ilot was described          as appearing
from previous     examination.    Lungs   were                                                                  clear                      ]tot, sweqting       profusely,      and fatigued,     lie was
throughout    and diaphrqgmatic      excursion                                                                    was                      lucid, although         not talkative,      aml had no med-
full.   Examination     of the heart  revealed                                                                   that                      ical complaints         other than being hot:there           was
lhe aorti<' second sound was equal to the pul-                                                                                             no other       sul)jeclive      evidence     of dehydration.
monte second serum when the examinee    was in                                                                                             After rem(>va] of his pressure             suit and a shower,
a sitting  position,   and the puhnonic      secon<l                                                                                       the pilot      beg.m       with    the shil)board      medical
souml was greater    than the aortic second sound                                                                                          debriefing.
when the examinee       was supine.     The <'ardiac                                                                                          A brief medical        history   of the sl)ace flight
s<mmls were of good qu,dily,        were not split,                                                                                        revealed     that in spite of vohmtary,          rather    vio-
and there were no murnmrs.       The abdomen     was                                                                                       lent head maneuvers          by the pilot      in flight,     he
well relaxe<l;                     there            was no tenderness    trod no                                                           specifically     note(l no gastrointestinal,         vestil)u-
mqsses.    The                     liver           edge was b,trely   palpable;                                                            ]at, nor disorientation       symptoms       while weight-

                                                                          TABLE                            8-III.--Clinical                        Evaluation

                                                                                    (All               times          are        Eastern        Standard)

                                                                               Preflight                       (launch               morning)                                                  Postflight

     General              status      ......                                   Eager                   for     flight          .......                  Alert,          but           not      talkative;                 sweating               pro-
                                                                                                                                                              fusely;           appeared                fatigued;               not      hungry.
     Weight,              lb                            _.                     171_%                      at 3:15            a.m                        1662%           at      6:50        p.m.        (5516     lb loss)L
     Temperature,                    o F ......                                98.2            (oral)                 ......                            99.2          (rectal          at     4:00           p.m.);            98.0      (oral      at
                                                                                                                                                              12:00          p.m.).
     Respiration,                  breaths/min_                _               14      ................                                                 14.
     Pulse,         beat,/mm               ....                                68 ............                                                          76     on     shit)board,                  72   at     Grand            Turk.
     Blood pressure,                        (left arm),              mm        118/80                     (sitting)            .......                  105/60           (standing)                ; 120/60            (supine)            "tt 3:45
       tIg.                                                                                                                                                   p.m.;          128/78           (sitting)           at      9:30         p.m.
     IIeart    and lungs                   .....                               Normal                           ..........                              Normal--                no     change.
     Skin ..................                                                   No       erythema                         or        abrasions_           Erythem.t                 of        biosensor                 sites;          superficial
                                                                                                                                                              abrasions                second            and          third           fingers       of
                                                                                                                                                              right          hand.
     Extremity                 measurements:                                                       Left                 Right                                                Left                                        Right
                 Wrist,        in .............                                                           6_                     7                                            6_4                                               7
                 Calf       (maximum),                 in .......                                  16+7_                       16}_,                                         165/_                                             16_
                 Ankle         (minimum),                in ......                                                                                                            9                                                 9J_

           Not      true        inflight           weight       loss   since        the             scales            were           neither     the   same           nor       compared                and       postflight              weight         was
4 hours,         8 minutes             after        landing.

     '   1

less.        I,ikewise,    he                              experienced     no            adverse                     beats/rain              and        regular.                There       were       two        Final]
effects      fr(nn isolation                               or confinement.               Specifi-                    superficial  skin abrasions    of the knuckles    of the
("llly, there       was no sensory      dei)rivation,        tIis                                                    second and third fingers of the right hand with-
flight    plan,     in addition    to tile requirenmnt          to                                                   out deformation      or fracture.     These    were l_e.-
control the sl)acecraft         on the fly-hy-wire     system,                                                       ceived when the plunger       of the explosive     'wtua-
kept Astrommt          Glenn very act ire and busy dur-                                                              tot for the egress     hatch    recoiled   against     the
ing the flight, and there was no so-called             "break-                                                       pilot's gloved   hand.   The skin also revealed         an
off" phenomenon.            As evidenced      t)y the numer-                                                         area    of moderate    reddening       and a pressure
ous inflight       reports,   by task performance,           and                                                     point at the site where the hlood pressure         micro-
by the onboard         film, the pilot's mental       and psy-                                                       phone had been attached.    Furthermore,     there
chomotor       resllon_s     were consistently      apllropri-                                                       was a mild reaction   to the moleskin    adhesive
_tte. Psychiatric'tlly,        both before and after, and                                                            plaster          v:hich       att'whed             the four           ECG        electrodes.
during     the flight, he exhibited        entirely     nomn'fl                                                     Head,     eye, ear, nose, and throat            examinations
t)ehavior,       tie (lid describe     a mild sensation         of                                                  were     normal.       The heart       rhythm,      size, and
"stoma(_h awareness,"      which in no way .tpproxi-                                                                sounds were normal,           and the lungs were clear,
mated    nausea    or vomiting.        This  sensation,                                                             without     physical     evidence     of l(x'al puhnonary
which cleared     Sllontaneously     in 11/2 hours,    be-                                                          collapse.      Abdominal        examination        was nega-
gan after the spacecraft        was on the water      and                                                           five, and the lower extremities           showed no swell-
during    the 20-minute      period   before  recovery.                                                             ing    nor evidence        of venous        thromt)osis.      A
At. the time of landing,         the amhient   air tem-                                                             general      neurologic      examination        was entirely
perature    was 76 ° F with 60 to 65 percent        rela-                                                           normal.       Urine     and blood samples           were ob-
tive humidity;       suit inlet temperature        was 85 °                                                         tained     for later     analysis.      (See tables       8-VI
F; c.abin air temperature            was 103 ° F.         The
pilot ingested     the equivalent      of only 94 cubic                                                                                                                                   -WEIGHTLESS
centimeters      of water     (applesauce      puree)      for                                                                       r                                  7
                                                                                                                                 700 F                                  F

the rather    long period    of almost 13 hours from
breakfast    at 2:50 ,_.m.e.s.t.    to shipboard      at 3:45                                                          VOL., 500[              CENTRIFUGE
p.m.e.s.t.       During    the flight,  he also ate one                                                                      300f             /- PRERUN
5.0-gram      sugar tablet    (xylose).   Gastrointesti-                                                                                 _      POSTRUN

nal function       while weightless,    as measured      by
xylose absorption,       was normal.       (See t_tble 8-
IV).       The fluid intake     and output is shown in                                                               SP. GR. 1.020}-            ,_'_                        -_.
                                                                                                                                                                                           I           /
table 8-V.                                                                                                                      1.010 _- // ///                                            _:>.,.x_.__
                                                                                                                                                                                            ....         _
                                                                                                                                                                   ,,       ,     ,   ,
                                                                                                                                                                                               56     48
   The immediate    postflight                                          medical    examina-
                                                                                                                        -29 MA-6
                                                                                                                        PRE DAYS A'/'/' /                           -24              12  24
                                                                                                                                                                          -12 I 0 TIME, HR
tion onboard  the destroyer                                          recorded   the follow-                               -8 DAYS J                                   LIFT-OFF   LANDING
ing vital   sign, s: rectal temperature,                                               99.2 ° F,
blood pressure,     190/60 mm tIg supine,                                               pul_ 76                                          FIGURE          8-2.--Urine                  summary.

                                                                         TABLE        8-V.--Fluid                   Intake       and         Out )ut

                                                                                                  Urine                      e.s.t.                       Fluid         Intake                        c.s.t.
                                                                                                Output          i

    Countdown                  .................                                            0 co                                                    0    CC

    Inflight         ...............................                                        2 800         cc             2:00     p.m.              3 94      cc                                   11:48       a.m.
                                                                                                                                                                                                    3:45       p.m.
    Post     flight,,        ship        .........................                          0     CC
                                                                                                                                                    240       cc water tea                          6:30       p.m.
                                                                                                                                                    265       cc iced
                                                                                                                                                    125       ce coffee                             6:50       p.m,

                 Total           ...........................                                    800    cc                                           724       cc

          See   also         table          8-VI.
          Specific          gravity,               1.016.
     3 119.5          grams            of      applesauce             puree   (78.7   percent          water)




                     -°_z_,      _
                                     i      i   i   .



                      k_             lilt

             =   _   __                              ,
                 _   -o_-                           ,

                            _'                      ,'


                                                                                              TABLE             8-VII.--l'eripheral                          Blood

                                                                                                                                          Preflight                                                                            Postflight

                                                                                                   Mar.                   Aug.                   Aug.                  -- 29                    --8                  +8        hr       i      + 46     hr
                                                                                                    1959                  1960                   1961                 days        I           days          1

        Hematocrit,                   percent   ........                                                  45                     45                  42                                         39. 5                          46                       42
        tIemoglobin                       (Cyan        methemo-
           globin            method),              grams/100                       ml_              15. 7                     15.3               13.6                   14.5                    14.1                      16.1                       14.7
        Red         blood          cells     X     lO_/mm            a ........                                                                                        4.75                    4..(t6                     4. _2                      5. 03
        White      t)lood            celLs/nml            3 ....                                   5, 000                 5, 000             6,310                    5,100                   4, 650                     s, 200                   5, 450
        Differential                white-t)lood                   comlt:
                    l,ymphocytt.s,                  percent                 ....              i           40                     41                  45                      37                       47                       36                      33
                    Neutrophih,s,                  percent          .....                    I            58                     49                  42                      57                       47                       58                      57
                                                                                                                                   6                  7                        3                        3                        3                          3
                    Monocytes,                percent          ........                  _                 1
                                                                                                                                     4                  5                      1                        2                        2                          5
                    Eosinophih_s,      percent      .....                                _                 1
                    Basol)hiles   , percent    ....                                                        l                         0                  1                      2                        1                           1                       2

           l)eterminations                        by      same         technician.

and 8-VII                      and fig. 8-2.)     The inflight                                                     urine                 (quding                 an          electroencephalogram,                                             was           un-
collection                   (levite  <_ontaine(1   800 cubi('                                                     centi-                changed                except  for slightly   increased                                                        deep
meters     of clear,     straw-colored     urine   with    a                                                                             tendon             reflexes, and the ophthahnologist                                                         found
specific gravity      of 1.016, pH 6.0, and was nega-                                                                                    normal              and un('lmnged     ocular function,                                                       with-
tive    microscopically       and for bh)od,      protein,                                                                               out slit lamp or funduscopic       evidence    of cosmic
glucose     and    acetone.     This   volmne    of urine                                                                                ray darn'we.      The internist   noted no change         in
was passed just l)rior to retrosequence;                  bladder                                                                        the lung fields nor in the quality       and character
sensation      and function           while    weightless      was                                                                       of the (,ardiac smmds.       The preflight     and post-
normal      and mwhanged             from that of the cus-                                                                               flight chest X-rays   and electrocardiograms          were
tomary     lg, ground        environment.                                                                                                compared;     neither abnormality      nor change       was
   At 5:45 p.m.e.s.t,          the pilot was transferred                                                                                 observed.     The identical,    special    labyrinthine
to the aircr'tft      c'u'rier    [:.S.S.    Randolph        where                                                                       tests      were         1)erformed                    in     all       effort      to          demonstrate

posterior-anterior,          and     lateral    chest     X-rays,                                                                        any effect of space flight upon the pilot's sense
standard      12-lead     electrocardiogram,          and body                                                                           of balance.  These postflight  labyrinthine      tests,
weight     were obtained.          Body weight         could not                                                                         and both the general    and specialists'    examina-
Im obtained                         sooner             due          to the                   rolling             of      the             tions,          revealed              no significant                            changes               from          the
(lest    royer.                                                                                                                          pilot's preflight                         condition.
      Later,           Astronaut                    Gleml                 flew           to       Grand            Turk                     There   were,                         however,                  _ few              measured                     dif-
Ishmd  where a general    1)hysical   examination                                                                                        ferences                between               the          preflight                and              l)ostflight
was begun   at .9:?0 pan. e.s.t., al)proximate]y                                                                                         medi('al            findings,                 and          these          are      summarized                          in
(;:}_    hours              after           sl)acecraft                     landin_z.                     The         vital
                                                                                                                                         table          8-III.               The        pilot          lost         only         slightly               more
signs          at     that          time          were:            b]ood             pressure,                   128/78
                                                                                                                                         weight             than             he       lost      during                   a Mercury-Atlas
toni       IIg          (left              arm,          sitting)                    pulse,               _z })eats/
                                                                                                                                         three-orbit                  simulation                    on the centrifuge.                                 Such
rain;           respiration                        14        breaths/rain;                                and          oral
                                                                                                                                         weight             loss,        coupled                with              a diminished                         urine
temperature,                        98 ° F          at      12 :()0            p.m.e.s.t.                       Except.
                                                                                                                                         volume   and increased                                     specific gravity                           after the
for       the          previously                      described                     superficial                      skin
                                                                                                                                         flight (see table 8-VI                                      and fig. 8-2),                           hemocon-
al)rasi<ms,                  the       entire            examination                               was         normal.

I)uring  the subsequent                                     48 hours,                             a coml)rehen-                          centration                   (see table               8-VII),                   and            the       recovery
sire examimttion     was                                   conducte(t                              by the same                           physicians'                  clinical               impression                    led to the                  diag-
medi('al specialists   who examined     the pilot                                                                     prior              nosis          of mild              dehydration.                          The       battery                 of bio-
to flight.    The psychiatrist's    examination                                                                         was              chemical                studies              (see tables                  8-VIII                   and      8-IX)
entirely   normal,   a neurologic    examination,                                                                        in-             further            supports                  tlfis         impression;                         however,                no

abnormality                    specifically                    attributable                 to      space                      Aeknowledgments.--Special                                               acknowledgment
flight,          as     opposed             to        atmospheric                 flight,          is evi-               is     paid            to     the       following                     for        their         assist'race
dent.         Astronaut                 Glenn            further           reported              no sub-                 in     the     medical                studies:                 Paul         W.       Myers,              M.I).,
jeetive            synq)toms                 of        dehydration                   other              than             and           Charles                 ('.         Watts,               Jr.,          M.I).,              Lack-
being            hot.          IIis         mihl          dehydration                       was           due            brad         Air        Force          Hospital,                 San          Antonio,                 Texas;
primarily                to    the         over|mating                 experienced                       just            W.      Bruce               Clark,          M.D.,          USAF                School             of     Aero-
prior        to landing                and            while      on    the        water            await-                space          Medicine,                    San      Antonio,                    Texas;                George
ing       pickup.              Also.             he     had         a minimal               fluid          in-           Ruff,              M.I).,             University                       of           Pemlsylvania;
take       for        almost          13    hours:             his    intake         and         output.                 Walter              Frojola,                Ph.         I).,     Department,                       of        Bio-
is      summarized                    in     table            8-V.         Itis       mild              post-            chemistry,                   Ohio           State         University;                      Kristen               B.
flight,           gastrointestinal                            "awarelleSs"                    is          also           Eik-Nes,                    M.D.,           University                      of       Utah;               Hans
attributed               to    the         increased             envirmmmntal                           tem-             Weil-Malherbe,                         M.I).,           St.. Elizabeth's                       Hospital,
perature              after       the        flight           and     to     mild           dehydra-                     Washin_on,                           D.C.;           Leonard                      Laster,                M.D.,
tion.         In        addition,                the     bobbing-             motion               of     the            N:ltional               Institutes            of Health;                      and        S/Sgt.          Carl-
sl)acecraft               on     the         sea        is undoubtedly                      :_ major                     ton     L.     Stewart,                 I,ackland                 Air         Force            Hospital,
contributory                   factor.                                                                                   San      Antonio,                   Texas.

                                                                            TABLE            8-VIII.--Blood                       Summary

                                                                                                                 Centrifuge                                                      MA-6           flight

                                                                                                                         Postrun                             Preflight                                    Postflight

                                                                                                                     3-2               3-6              --29            --8                      +1               3-8           +46
                                                                                                                      hr               hr               days           days                      hr               hr             hr

        Glucose   (whole blood) mgm;100               ml_                               _ _               97         112            121                   95               109                   --                96             99
        Sodium    (serum),     mEq/L ............                                                        143         140            154                  155               160                   146              144            143
        Potassium     (serum),    mEq/L__                                                                4.8         4.8'          5.6                  5.4                4.6                   3.9              4.4            4.4
        Calcium    (serum),     mEq/I ...............                                                5.2             6.0           5.2                  4.9                4.3                   4.3              4.2            4.4
        Chloride     (serum),    mEq/L .....                                                           80             83             83                   95              98                     104           104               104
        Protein   (total serum),       g/100 ml__                                                    7.9             7.7           8.0                  6.9             6.6                      6.9           6.6               6.7
        Albumin      (serum),    g/100 ml .....                                                      4.3             4.1           4.7                  4. 1            3.8                      3.8           3.8               3._
        Albumin/Globulin          ratio (serum)        _                                             1.2             1.1            1.2                 1.4             1.4                      1.2           1.4               1.3
        Urea Nitrogen        (serum)     mg/100 ml.                                                 15.4           16. 0          14. 3                14. 1           15. 5                    10. 5         10. 5             11. 6
        Epinephrine,      plasma _,g/I .......                                                     <0._           <o. 1          <o,                 <0. 1           <0. 1                 <0. 1 <0. 1 <0. 1
        Norcpinephrine,        plasma _,g/l ..........                                             <0.1           <o._           <o.        1          5.0            18.0                   --    6.0   3.8

        Operational            priorities             precluded        making          a biochemical                requirement                 for fasting           specimens.

                                                          ii1_11              i

                       _        ÷

                                        i            _    i i ,    i i ,
                                                                              i              i


                                                                                    i   i   I

                                                                                    i   i   ,


                                                                     i                  i
                                    i                 i                  i          i   i


                                                ii             i

    I                      _÷



634401   0---62----7
 l)ot-(;LAs,               V_'H.HA_,                     K...TA('K_ON,                          ('AR',IAI[,T                       I_., .It,,      et     al,        :      Rcs'ult._           o[      the      MI_         /t Prcfliqht                    _ll_,d Po,_'tflight               Medical
    ExanTil_(ttion                       CoIIductcd                      (.i           Astro...t                            l'irgil  f. Gri,_'._om.                          Results             {ff _h(,           _qe('-II(1          l'.S.      Malm(.d                SulJ-rbit_l                Spa('('
    Flight,     July                   21, 1961.                      NASA              Manm,d                            Spacecraft     Center.
.IACI,:SON,               ('ARMAt'I.T                         1$., .Jr.. ])()('I;I,AS,                            V_'II.I.IAM              K.,     ('t al.           :      l¢_'stllls           of     Preflight                a.d          l'o,_tflight           Medical              E,r_l.ti._t-
    lions.                Pro(,.           Conf.              on       Result._                 (_f tim               First            V.S.       Manned                  Suborbital                   Spar(=         Flight,               NASA.            Nat.      Inst.        tte;tllh,             and
   Nat.         Acad.              Sci.            June               (k 19(;1.          pp.          31-3(;.
Glucose          :
         NEI.SON,                  3[.:           Photometric                          Adapttttio.                              o]" Nomog_ti                   Method                 f_."     1)ct_'rmi..ticm                         of     (il.cosc.              Jour.          Bi(d.       Chore.,
               vol.         153,           1:144, Pl). 377"r-3_¢0.
Total         protein,                 albumin                   :
         COIl5,',            C.,     and     _VoLFsON,       _,V. G. : Nludic._                                                         i}l, Ncrum                   Protci..s'.                 I- The      (rhcmical     E,_limatio.                                     of     .llb..li_               alld
               of         the       Glob.li_     Fractiol_._      i. St'rum.                                                           JOlll'. I.ab.                 Clin.     3led..              v,,1. _1:2. 1_._t7, pp. 120q-1207.
         GOI{NAIA,,                    A.         G.,          BARDAWILI,,                           C.       J..          and         I)AVlI),          M.._I.             : Dclt'rmi.¢ttiol_                        of     Scr,m               l'rotci.._               b!!     31catJ._          ¢Jf the
               Biurct               l:cactio..                        Jour.            Biol.           (_hom.,                  vol.     177,      1949,            pp.      751-7_i(i.
Urea          nitrogen                 :
         GE-XTZKOW,                          C.         J..     and           ._|ASI,]N,              J.      3[. ; ..lit, .-lecuralc                           Mt'thod               for       the      l)t'lecmi.ttli.,                       tJf Blood             Urt'a         NitroycJi               by
        Direct                     NesMcrizatiom                                     Jour.             Biol.               (_hem.,         vol.      143,           1942,        I)P. 531-544.
Calcium    :
         DW.IH_,                II.,         and              F;LLLn'_;_O_:,                    .T.L.             : Indicator                    for          Titratio_                .f      (Y_tlci..i            i..     1)rcm'.cc                  of    Maytwsiltt_t                With             Di-
               ._odi.m,                Dih!ldrogc_                            Eth!lh'nc                     ]}ia.ti.ctctraqcctatc.                                          Anal.            ('h(_m..         w_t. 2_,            1956,          lip.        g82-NS4.
Chloride              :
         SCIIALES,                     O.,        and           SCIIAI.EN,                  S.         S. : .[                 Simple          a_d        .4ccuratc                   ]l_'thod           for        the      llctcrmi.ation                         o;e ('hloridc               ill Bio-
               logical              Fluids.                     ,Tour.          Biol.           Chem.,                     vol.     140,      1941.           Pl). 87 TM
Epinephrine                        and           norepinelthrine                            :
         WEIL-MA_.HERr_E,                                      II.,         all(1      BONE,                A.            I). : The           .4drcllcrgic                   .lmi.cs              .f     lI..tttlt           Illood.               Lancet,            vol.        264,      1933.          pp.
         GRAY,               I.,       YOUNG,                   J'.     G.,         K_:EC, AN, J.                          b'.,     5[E||AMAN,                      B.,     "tIl(l      _OUTIII':I_I.ANI},                   n.        _V. : ..ldrc.ali.c                        ol_d     Norcpinc-
               phrinc                  Co_tcc.tration                               il_. Plasma                           of      tIuma_,,              a.d          l¢(tt,,.          Clin.           ('hem..            vol.     3, 1957.               Iq).      239-24g.
Sodium              I_()tassiuln                    by         flame           phot_lnetry                            :
         BERKMAN,                          S.,      HENRY,                   R..]'.,            GOLUI_,                    O. J.,       _|nd       SEA(IAI,OVE,                      M. : 7'U.y._tic                 Acid          t'rccipilatio,                    of         Blood       Protein._.
               Jour.            Biol.            ChelH.,               rot.         206,        1954,              1)P. 937-943.
Vanyl          mandelic                      acid         :
         SUNDERMAN,                               F.          W..           Jl'.,      ct           _[l.:         A        Method                "for         thc         llr'lcr.litl_ttio.                     ¢_f ._-Jlclhoa'y-tt-llydroa'yl._l.dclic                                                 Acid
                ("Vanilmalt,dclic'                                    Acid")                f_r            th('           Diag,_mis                of     Phcochro,tocytomu.                                        Am..l_ur.                   Clin.         I'ath(d.,            vol.       34,        1_0,
               pp.         -'293-312.
IIeat-stqble                    lactic             dehydrogenase                                :
         STRANDJORD,                             PAUI,                E..      all(l        (_I.AYSON,                          KATIII.EEN                C. : The                   ])i¢l[lllosi,s            of     .t_',te               Myocttrdi_tl              Infarction                    o_     the
               Basis               o]        Hcat-Stablc                            Lactic                 Dchydrogcnasc.                                 Jour.             Lab.         Clin.          Med.,         vol.         5S,        1961,          1)P. 962-,_6.

            9.    PHYSIOLOGICAL                          RESPONSES             OF      THE        ASTRONAUT

By C. PATRICK LAUGHLIN,               M.D., Li]e Systems   Division, NASA           Manned Spacecra]t          Center; ERNEST P.
    McCuTcHEON,  M.D.,              Li]e Systems Division, NASA Manned              Spaceera]t Center;        RITA M. RAPP, Li]e
       Systems Division, NASA Manned Spacecra# Center; DAVID P. MORRIS, Jr., M.D., Li]e Systems Division,
       NASA Manned Spacecra]t Center; and WILLIAM A. AUGERSON, M.D., U.S. Army, Ft. Campbell, Ky.

                          Summary                                     are many     unexplored      study        areas and future
                                                                      flights will provide    additional         information.
   The   MA-6     mission          provided     a period     of
extended  weightlessness           during   which tile astro-                    The Space       Flight   Environment
naut's   p]tysioh)gical  responses      al)parently   sta-
bilized.    The vahles attained    were within ranges                    The astronaut's   activities     during        the time im-
compatible      with normal    function.       No subjec-             mediately    prior to the countdown               are noted in
tive   abnormalities       were     reported     by   the   pilot.    paper    S. A 38-minute         hold was          called   after
                                                                      the transfer      van arrived       at the launch pad and
                        Introduction                                  the astronaut        remained       in the van until  5:58
                                                                      a.m.e.s.t,  when he ascended       the gantry.     Inser-
    The orbital     space flight of Astronaut              Glenn      tion into the spacecraft      occurred     at 6:06 a.m.
has l)rovided     a sig_fificant      addition     to the body        e.s.t., and continuous    physiological      monitoring
of infol_nation       reflecting      human      responds        to   began at this time.      He wore the Mercury          full-
this new situation.          The life-science         objectives      pressure   suit and was positioned       in his contour
of the flight     included       the study of the effects             couch in the semisupine     position,    with head and
of weightlessness,        launch and reentry           accelera-      back raised     12 ° from the horizontal        and hips
tions, and weightless          transition      periods.       The     and knees flexed at approximately            90 ° angles.
much     shorter     Redstoue       ballistic     flights     per-    A shoulder     and lap harness     secured    him in the
mitted    little time in the weightless              phase     for    couch.    During    weightless     flight the spacecraft
physiological      adjustment        mechanisnls        to stab-      was oriented     so that he was in a sitting position
ilize.   The MA-6 nlission           provided      a period of        relative   to the earth's    surface.     At reentry     he
weightlessness      of sufficient duration          so that the       was exposed     to the force of inertia     in the supine
pilot's physiological      responses    attained     a rela-          position.
tively steady state.       In addition      to the biosen-                After     completion       of suit   purging       he was
sor data,    the pilot's     subjective    evaluation      of         maintained        on 100-percent      oxygen     at 14.7 psia
general   body    sensations     provided     a very im-              until     suit and cabin pressure          declined     during
portant   source of information.           His comments               launch.        Cabin      and suit. pressure       regulation
regarding     body function,       such as, spatial  orien-           l)roceeded      normally,      and levels were stable           at
tation, eating,    urination,     and task l)erformance,              al)l)roximately         5.7 and 5.8 psia,       respectively,
were regarded       as most significant.       Additional             until snorkel        valve opening     during     the reentry
information      on the operation       of the spacecraft             sequence,      after     which   ambient     air was intro-
environmental      control    system and the bioinstru-               duced into the system.
metltation    system     was also obtained.                              The total time in the spacecraft               during      the
   The   approach       to these    studies    remains      essen-    prehlunch     period    was 3 hours and 41 minutes.
tially as otltlined       in the MR-3 and MR-4 post-                  I)uring   this period      the astronaut,        performed
fligllt   reports     (refs.   1 and '2).     Physiological           numerolls    spacecraft    checks and prevented            fa-
investigations        must comply        with   the overall           tigue with frequent      deel)-breathing        and muscle-
oI)erational      requirements     of the mission.      There         tensing   exercises.      Lift-off     occurred      at, 9:47

           a                        a
a.m.e.s.t, ndthe flight proceededsplanned.                             The total biosensor     monitoring    time, from
Accelerations  during powered flight werefrom                       astronaut  insertion  until just prior to landing,
lg to 6.7gin 2 minutes and1(1seconds  (booster-                     was 8 hours      and 33 minutes.      The biosensor
enginecutoff,BECO), and from 1.4gto 7.7g                            readout    quality   was excellent    throughout      the
in the following 2 minutesand 52 seconds                            countdown      and flight with the exception      of the
 (sustainer-engine cutoff,SECO). Spacecraft                         respiratoi T trace.    As in prior flights, variation
separation  fromthe launchvehicle   andthe be-                      with head position      and air density    combined     to
ginning of weightlessness   occurredat T+5                          reduce    the quality     of the respiration       trace.
minutes and2 seconds.                   m
                        Thethree-orbit ission                       There     were brief periods   of noise on the ECG
         in                  p
resulted a total weightless eriodof 4 hours                         channels     during  countdown    and flight, usually
and38minutes.                                                       occurring     during  vigorous  pilot activity.
   Reentrybegan             at
                  with 0.05g T+4 hoursand
43 minutes. Maximum reentry acceleration
forcesof 7.7goccurred T+4 hoursand47                                    During    approximately     45 minutes     in the
minuteswith gradual buildup from lg and                             transfer   van, the astronaut's   pulse ranged   from
gradualreturnto lg overa periodof 3 minutes                         58 to 82 beats/minute       with a mean of 72 and
and30seconds. ith mainparachute         deploy-                     the blood pressure     was 12'2/77 mm Hg.
mentatT+4 hoursand50minutes,herewasat                                  Figure    9-1 depicts the pulse rate, respiration
brief 3.7gspike. The spacecraft   landedonthe                       rate, body temperature,        suit-inlet   temperature,
waterat T+4 hoursand55minutes, :43l).m.                             and blood pressure       values recorded       during     the
e.s.t.                                                              MA-6      countdown.      Values      at selected     events
                                                                    for the same physiological       functions      obtained
           Monitoring        and    Data    Sources                 from the simulated    launch of January         19, 1962,
                                                                    and the launch attempt     of January      27, 196'2, are
    Data  reflecting       physiological        responses     to
                                                                    also shown.    Pulse and respiration         rates were
flight were obtained        by evaluating       the biosensor
                                                                    determined   by counting    the rates for 30 seconds
real-time     recordings        from range        stations    and
                                                                    every 3 minutes    until 10 minutes    prior to lift-
from the continuous           onboard     recording.       In ad-
                                                                    off when 30-second     duration counts    were made
dition,   various     in-flight     tests and the pilot-ob-
                                                                    each minute.
server    camera      film were utilized           for further
                                                                       The pulse rates during    the launch attempt             of
objective   analysis.       The reports     of values      from
                                                                    January      27, 196'2, varied     from 60 to               88
the range medical         monitors    provided    vital     con-
                                                                    beats/minute     with a mean of 70 beats/minute.
tinuous   coverage      enabling   accurate    appraisal      of
                                                                    These rates were essentially   the same as those
the astronaut's       status during      the flight.       Sub-
                                                                    observed  during the MA-6 countdown,    as shown
jective evaluation        included    pilot reports        from
                                                                    in figure 9-1.   Respiration rates were similar,
onboard      voice recordings        and the postflight      de-
                                                                    varying     from 1'2 to 20 breaths/minute.              Blood
briefing.     The countdown          period provided      base-
                                                                    pressure     values from the simulated         launch     also
line preflight     information.        Useful comparative
                                                                    approximated        tho_ observed  during  the MA-6
measurements          were available     from the Mercury-
                                                                    countdown.         A pulse rate of 110 beats/minute
Atlas     three-orbit      centrifuge      sinmlation,     pad-
                                                                    and    a   blood    pressure     139/88     mm     Hg     was
simulated       launch,     simulated       flights,   and the
                                                                    observed     at lift-off.
January      27,196'2, launch attempt.
                                                                       The low suit-inlet      temperature     maintained
                   Bioinstrumentation                               during  countdown     resulted    in the pilot feeling
                                                                    cold and was accompanied           by a fall in body
    In addition     to the type of bioinstrumentation               temperature       from   98.6 ° F at insertion      to 97.6 °
used in the manned            Mercury-Redstone        flights       F at lift-off.
 (two ECG        leads, respiratory      rate sensor, and             An examination       of the electrocardiographic
body-temperature           sensor),    a blood     pressure         waveform    obtained     during    the MA-6       count-
measuring       system    as described     in paper 3 was           down revealed     't number     of variations      in the
utilized   in flight.     Preflight   and postflight     cali-      pacemaker        activity    which    had been observed
brations     of the I)lood pressure        system    showed         i)reviously.      These included        sinus pauses, sinus
no significant      change.                                         bradyeardia,       t)remature    atrial    and nodal beats,

                        140              I


          _                .10

          _                65

          = _ 55



                    _ s_7
                                                                                                                                                                                                                                           %/'       Simulated
         120                                                                                                                                                                                                                                         launch




     E              !

                                                o                                                          o                            o


 ,        60-


          40'--               30


                     _ 20

                              10                                                    0

                                                                                                                   t                         I                          I              f          _             I                    I           J

                                             -141                                -115                          - 100                   -85                                                  -60

                                                                                                                          Countdown              time,       minutes

                                 06:00               06:10        06:20                 06:30          06:40            06:50            07:00                         07:10        07:20             07:30         07:40          07:50                  08:00

                                                                                                         Eastern       standard       time,              hours:minutes:seconds

                                                                                                (a) Countdown 06:00 to 08:00 a.m.e.s.t.
F_otmz                           9-1.--Preflight : Respiration                                  rate, pulse rate, body                           temperature,                    sult-lnlet temperature,                    and   blood pressure
                for MA--6                           countdown             with    values          at selected events                    from                the simulated                   launch        of January          19, 1962, and                       the
                launch                       attempt         of January          27, 1962.

and premature      ventricular     beats.      On several                                                                                        were not observed  at any other time.      All of the
instances    some of these reported          findings     oc-                                                                                    above are not unexpected       physiologic      varia-
curred    with deep respiration.          Similar     varia-                                                                                     tions.  (Samples  of MA-6 blockhouse          records
tions    were also recorded      from the simulated                                                                                              from the time of insertion  and at T- 50 seconds
launch                             of January                   19 and           from            the     launch            at-                   are shown                     in figs. 9-_ and 9-3.)
tempt of Januar),         97.     In addition,     a brief (16
beats)    run of atrial       rhythm      with a rate of 100
beats/minute        occurred      during     countdown,      and                                                                                    Figure  9-4 illustrates      the inflight   physiologi-
an isolated      run (19 beats)         of a rhythna      origi-                                                                                 cal data and includes        values from the Mercury-
nating     adjacent     to the atrio-ventricular           node                                                                                  Atlas three-orbit     centrifuge    simulation    for com-
with aberrant        conduction        occurred    during     the                                                                                parison.    Minute      pulse rates were determined
attempted      launch of January.           _ , however,   these                                                                                 by counting       every    30 seconds      during     MA-6

                          1 ,t 0

                          120                                    T                                                                                                                                                T
                     := 100                                "r
                                                            i     I

             _              _o

             _             4O

             2_ _ 65

             _       m      55


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                                                                                                                                                                                                                                                                                ",     S:ru,A<lt        ,,d

              40-          30

                                                                                                                                                                                                                                                                                       Can,     eh,<l
                                                                                                                                                                                                                                                                                       lain,    h

             =              20                                   O

                                                                                                               I_                                           _       Trace          canreadable            _'
                                                                                              O                i_       ¢         :

                                                                             o                 g                                                                                                                                                             e      f            _       i
                                                                             >                 >

                                                                                                                                                                                                                                                                     =           ___            ,

                                                                 =r+         _                 =

                                                                                                                                                                                                 Hohim        g   ; o,n,t
                                              i                   I      I               I     i                                                                                                                                       (
                                        -60                                        -45                                  45                                                    22                                                      '22                  -io            -.

                                                                                                                                                 Countdown            time,           millut-oN

                             08    : 00               08        : 10             08   : 20                0B : 30             08:40                    08   : 50              09:00                  0._! : t o                tit    211         0_:30            tJ_* :.Io              o_       50

                                                                                                                    Eastern           standard              time,        hours:m_nutes

                                                                                                   (b)     Countdown,   08:00 to lift-off, 09:47                                                         a.m.e.s.t.
                                                                                                                   FIGURE 9-1.--Concluded.

launch                    and              reentry                       and             for             30    seconds                  at        3-                 wit h a inean                             rate           of 86 beats/minute                               during                   the
minute                     intervals                        tliroughout                              the         remainder                        of                next              3 hours                     and          45 minutes                  of     flight.                 At            the
the        fliglit.                       Because                      of tim                variation                in the            qual-                       time              of     retrorocket                             living       tim      rate      was             96 beats/
ity         of            the             respiratory                                 recording,                       rates              were
                                                                                                                                                                     niinute.                      During                     reentr          3- acceleration                    and           para-
counted                       for          30         seconds                      whenever                         possible                 and
                                                                                                                                                                    chute               descent                   the         Iileali       pulse         rate     was          109 beats/
varied                   froni            8 to             19 breaths/niinule                                         throughout
                                                                                                                                                                     niinute_                and              the liighest                      rate      wits    134 beats/rain-
                                                                                                                                                                    tile           just          l)rior             |o        droo'ue            parachute                 deploynlent
      The                pulse            rate             from              lift-off                to spacecraft                         _p-
aration                    reached                        a maximum                                 of        114      beats/niin-                                  at        it       thne              of        liiaxilillllii                si)acecraft                   oscill'ition.

ute.              The                pulse                  rate             varied                      froni           88       to             114                Tills             rate         was             tile        highest            noted           during               the         mis-

beats/ntinule                                     in the                first         !0           niinutes             of      weight-                              sion.                 Tliese                  rates              indicate             that          aceeleration_

lessness.                          It             tllen                renlained                         relatively                    stable                       weightlessness,                                      and          return           to gravity                    were           tol-


  FIGURE 9-2.--Sample          of blockhouse     physiological   record at insertion,          6:06 a.m.e.s.t.        Lead 2 is inverted.
                                                    (Re('o rder spee d 25 mnl/sec).


EGG      I

                                                                      A   i    .i
                                                                     _J_!____.                 I i I                                  ,_i i

FIGURE 9--3.--Sample         of blockhouse     record at T-50 seconds. 9:46 a.m.e.s.t.,                with blood pressure      tracing,   value
                                               139/80.   (Recorder s'peed 25 mm/sec).

eraled        within  acceptable     physiological        limits.             mean     pulse    rate     of   six   astronaut     centrifuge
Figure         9-5 (_omi)ares    Astronaut       (;lenn's      in-            simulations.
flighl pulse tale,        his pulse rate during       Mercm T-                    The E(X;      variations     noted       during   the pre-
At las three-orbit         centrifuge  simulation,      and the               flight, observation       period   were      not observed    in

flight.        Analysis   of the                                inflight      record  re-                Ten blood pressure   determinations                           were made
vealed        only normal    sinus                               rhythm       with short              in flight; the first at T+18    minutes                         and 30 sec-
periods of sinus bradycardia         and sinus arrhyth-                                               onds and the last at T+3 hours and                              14 minutes.
mia.    There     were rare periods       in which trace                                              The values are shown                     in figure 9-4, and range
quality     deteriorated     so that    only pulse   rate                                             from 119 to 143 mm                      Hg systolic   and from 60
determinations        were possible.    The ECG varia-                                                to 81 mm Hg diastolic.         The mean blood pres-
tions     noted during                    Astronaut                Glenn's    MercuD.-                sure values and the ranges from physical             exam-
Atlas       three-orbit                    centrifuge                 simulation     in-              inations,   static procedures    trainer     simulations,
cluded:   sinus arrhythmia,       sinus                                     bradycardia,              Mercury-Atlas      three-orbit    centrifuge       simula-
atrial and nodal premature       beats,                                    and rare pre-              tions, launch pad tests, MA-6                            countdown,    and
mature    ventricular   contractions.                                          These     are          the MA-6 flight are presented                           in the following
interpreted              as normal                    physiological           variations.             table :

                                                                                             Number              Mean            Mean               Systolic               Diastolic
                                                                                             of deter-           blood           pulse               range,                 range,
                                      Data            sources                               minations          pressure,       pressure             mm Hg                  mm Hg
                                                                                                                mm Hg

     Physical       exams     ..................                                                 14             l 10/66              44             98 to     128      60     to   80
     Procedures        trainer        ......................                                     15             121/76               45            ll0   to   132          66 to   87
     3-orbit    Mercury-Atlas               centrifuge                simulation_      __        56             114/80               34             92 to     136          68 to   92
     Launch-pad        tests .............                                                       26             104/76               28             91 to     125      64     to   91
     MA-6     countdown           .................                                              14             123/87               36            101   to   139      83 to       93
     MA-6       flight    .........................                                              10             129/70               59            119   to   143      60 to       81

   The MA-6 inflight         mean pulse pressure          shows                                       rise after     reentry       and during             parachute           descent.
some widening         when compared          with preflight                                           During     descent and while awaiting          recovery     on
values.      This widening        appeared      after    1 hour                                       the     water,     the   suit-inlet     temperature        in-
of flight      and    is of uncertain         physiological                                           creased    approximately         1 ° F per minute       for a
siguificance.                                                                                         15-minute      period   and probably       contributed      to
   Samples      of physiological      data from playback                                              the pilot's overheated     status observed   at egress.
of the onboard      tape and from range stations             are                                      Since biosensor    disconnect    occurred  13 minutes
shown in figures 9-6 to 9-9.                                                                          before loss of telemetry  signal,                          the maximum
   The inflight      exercise    device    is illustrated      in                                     body temperature    may not have                          been obsem'ed.
fignlre     9-10.     Exercise    was accomplished        by a
series      of pulls on elastic         bungee   cords.     An                                                       Pilot     lnflight           Observations
exercise       period over Zanzibar        on the first orbit                                            The     astronaut's              voice    reports          were      consist-
raised      the pilot's pulse rate from S0 beats/min-                                                 ently accurate,  confident,     and coherent      through
ute to      124 beats/minute        after 30 _conds.       The                                        all phases of the flight.      His voice quality       con-
pulse      rate returned       to 84 beats/mimlte       within                                        veyed a sense of c_)ntinued         well being and his
,o minutes.           The blood pressure   before exercise                                            memal    _ate appe-Lred     entirely    appropriate      for
was 129/76           and after exercise was 129/74.   This                                            the situation.    The pilot's       mood and level of
response   is within     the previously     observed                                                  performance            were         effectively     conveyed     by his
values from exercise    in the procedures     trainer.                                                voice reports.           His        prompt      responses    to ground
   The environmental     control system effectively                                                   transmissions           and         to _unds        from    the space-
supported   the pilot throughout    tim mission.       It                                             craft suggest     no decrement    in hearing     ability.
should  be noted                     that body    temperature      grad-                              Vimlal acuity      was maintained      and his report
ually rose. from                     a lift-off value of 97.6 ° F to                                  of visual    perceptions,   especially    with    regard
99.5 ° F at the                     time of biosensor       disconnect.                               to colors,   was ,'wcurate and was confirmed            by
The    suit-inlet             temperature                          increased slowly                   the inflight   photographs.
during     most             of the flight                       with a more rapid                        The pilot& voice report      contained     a number


     |      so

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            65   --

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 .,_ .     99

 _          9s



;....                                                                 !i
     9O •

                      J    -\
     7oi         /               _                                             _


                                                                                               I                                     )                 )         i                        t                 I
                                                                                            00:50       01:00          01:i0         01:20           01:30           01:40     GI:50          0_:00        02:10      02   20     02 30
              oo:oo                  oo:1o         00:20      00:30         00:40

                                                                                                                Elapsed    tl_e)    hour.:minutes

                                                                                      (a)      Flight     elapsed           time         00:00      to 02:30.

FIGURE               9-4.--Flight                    : Respiration            rate,         pulse   rate,        body          temperature,                blood       pressure,       and       suit-inlet         temperature
                               during        the      MA--6     flight,      with       values      from         the      Mercury-Atlas                    three-orbit       centrifuge               simulatlon.

of observations of physiological           significance.                                                                           feeling of acceleration        opposite from flight di-
During his postflight       debriefing these reports                                                                               rection ("back to Hawaii")             was noted.   This
were amplified.     Those considered of most sig-                                                                                  could be expected with the sudden cha_ge in
nificance are discussed below.                                                                                                     spacecraft    velocity.      The pilot noted no dif-
   No disturbances     in spatial orientation        were                                                                          ference in the sensations          associated   with re-
reported,    nor were any symptoms           suggestive                                                                            entry    accelerations       from those experienced
of vestibular disturbances      described during the                                                                               during launch.
flight.   Voluntary     rapid head-turning         move-                                                                              Food chewing and swallowing              were accom-
ments produced no unpleasant           sensations.     No                                                                          plished without difficulty.           No water as such
sensory deprivation     or "break-off phenomenon"                                                                                  was ingested during flight.
was note_l.                                                                                                                           The pilot urinated without difficulty shortly
    A brief sensation        of tumbling       forward,                                                                            before reentry.      He described "normal" sensa-
similar to that described        by the astronaut        in                                                                        tions of bladder        fullness with the associated
the MR-4 mission, occurred             just after sus-                                                                             urge to urinate.
tainer-engine    cutoff (SECO).         This sensation                                                                                Tim astronaut     described weightlessness as a
ended promptly       and w_ not associated with                                                                                    "pleasant"   sensation and control manipulation
nausea.     Coincident with retrorocket         firing, a                                                                          was not affected.

                                                                                                         i                                                       '                      _,x                       :]          ,   i
                                                                                                         t                                                                               \

                                                                                                                                                                                             ( ,_:]i   t t_ugp


                 75                                                                                                                                                                    Conclusions
        SUIT     65          .                .-
       INLET      55

T,*F            I00

       BODY      97                            z         1
                                                                                                                                                          1. The     physiological    responses      observed
                 25                                                                                                                                    during   the MA-6 mission are all consistent       with
  RESP/M         15                    "           ":
                                                                                                                                                       intact  systems     and normal    body   function.
                                                                                   MA-6       FLIGHT                  I
                150                                                                                CENTRIFUGE             (GLENN)                         2. The MA-6               mission    provided      an exposure
                                                                                                         MEAN    CENTRIFUGE
                                                                                                                                                       to weightlessness             of sufficient    duration    to per-,

               IlO                             #
                                                                                                                                                       mit physiological               responses                 to re_ch     a relatively

   RATE          90
                                                                                                                                                       steady state.
                                                                      MA-     6                                   i

                      B                                               CENTRIFUGE              (GLENN)
                                                                                                                  I                                       ,L No symptoms                  reflecting               disturbed  vestib-
                                                                      MEAN         CENTRIFUGE                     i                 • '_

         q            4                                                                                                                                ular function  were               reported.                 This lack of find-
                                                                                                                                                       ings      occurred         even            though           specific       attempts
                      600         800               5         I0     55      I00       145      IRO      235     280         285           290   300
                                 EST                                               TIME,     MIN                                                       were      made    to stimulate                    the vestibular           system      in
FIGURE                      i_-5,--Comparison                        of Astronaut                            Glenn's                inflight           flight.
       physiologic                         data,    his       data          during                 the         Mercury-Atlas
                                                                                                                                                          4. The        pilot's     subjective                    evaluation            of   his
       three-orbit                         centrifuge                simuhlti(m,                         lind              the             mean
       physiologic                         data     of       six      astronaut                       centrifuge                           simu-       body      processes        nnd    sensations                 during        the    flight
       lations.                                                                                                                                        _11 conveyed          nornial         function.


  ECG            Z

                       •        [_     !!r!      :

                 .     :        ;'If:         i .
 .2     ......         i        __ i          Z_.i   i_

 FmURE               9-6.--Sample                    of      physiological            record       received        at    Bermuda              Range     Station        during          powered    phase       of     flight,
                                                          approximately           4 minutes           after      lift-off.          (Recorder         speed     25     mm/sec).


FIGURE           9-7.--Sample                        of     playback         record      from       the       onboard        tape      showing         physiological            data      after   2 hours          and     53
  minutes                  of        weightlessness,               with      inflight      blood      pressure           trace,       value      of   135/64.          (Recorder          speed   10 mm/sec).

   5. Acceleration-weightlessness        tnmsition      pe-                                                                  lessness did not l)roduce                          any unexpected                symp-
rio(Is did not l)roduce any recognized        physiolog-                                                                     tOnlS and l)hysiological                           data remained                 within
ical deterioration.        Specifically, reentry    accd-                                                                    fmmtionaI   _ilnits.
eration   after 4 hours and 38 minutes        of weight-                                                                          6. The         environmental                     control        system            effec-


                                                              III!I! !                                                                                                           -4-----4---

                                                                                                                                     ._ _                  .--
                                                                                                                                             .....                     "_- _               ---

                                                                           ::_   :=   :_: i:_! !!!:    !::!   fill   :i i :!i!

                                                                                                                                                                                 i     i

                                                                                          iii_i ,,,,
                                                                                                                                                              !                   ,_

                                                                           _- _,_
    i i_ii i!! iil ii! _!! !il

                                                                           ,             ii.....
                                                                           -'                                 i!

Fiotrim     9--8.--Sample        of    physiological          record    received      at              the Hawaii                     Range   Station   corresponding      to figure            9-7.
                                                                 (Recorder       speed                25 mm/sec).

tively supported                 the       pilot       throughout                the                  Haekworth,     Life Systems                                 Division, NASA
mission.                                                                                              Manned     Spacecraft  Center;                               and Charles D.
   :telcn,owledgm_n,ts.--The                       authors        gratefully                          Wheelwright,     Life Systems                               Division, NASA
acknowledge              the invaluable          assistance         of : Robie                        Manned Spacecraft. Center.

                                                                                           !i!            iii! ili iiii
                                                                                                          iili iiii
                                                                                                          iii! ii!i
                                                                                                          _!ii iill

FIGURE     9-9.--Sample                 of    playback              record     from          the    onboard          tape          showing          physiological            data       at     drogue        parachute
                 deployment,            approximately                  4 hours        and        49 minutes              after      lift-off.        (Recorder             speed       25 mm/sec).

                                                                    F_GURE         9-10.--MA-6                inflight           exercise        device.


1. AUOERSON,           WILLIAM               S.,        and   LAUGHLIN,               C.     PATRICK:            Physiological                  Responses           of     the     Astror_aut           in   the     MR--$
       Flight.        Proc.        Conf.           on    Results       of    the     First         U.S.     Manned           Suborbital              Space       Flight,         NASA,         Nat.     Inst.      Health,
       and Nat.        Acad. Sci., June   6, 1961, pp. 45--50.
2.   LAUGHLIN,         C. PATRICK,    and    AUGERSON,    WILLIAM                                          S. : Physiological                   Responses           o_     the     Astronaut            in   the     MR-_
       Space        Flight.         Results              of   the     Second          U.S.         Manned         Suborbital                Space      Flight,       July        21,    1961,     NASA             Manned
       Spacecraft             Center,        pp. 15-21.

                                  10.      ASTRONAUT                   PREPARATION

                       By M. SCOTT       CARPENTER,      Astronaut,    NASA        Manned       Spacecra#               Center

   Many hours were profitably               spent in special-
ized training activities, such            as spacecraft   sys-
tems discussions      and operation,      mission and sys-
tem procedures          and     simulated      emergencies,
physical    fitness, and egress and recovery.            Also
of great    value were the many hours               the crew
spent, participating      directly    in spacecraft     prep-
aration    and checkout       operations.       In addition,
much time was spent in the study of terrestrial
 and extraterrestrial      features     in preparation      for
scientific   and space-navigation          observations       in
orbit.   All of these training      and study activi-
ties contributed      greatly to crew readine_ss   for                    FIOURE 10--1.--Spacecraft                     13 systems         briefings.
the orbital    mission.

                                                                        were      devoted           to     the     notes        and        publications
                                                                        which       applied              specifically         to      spacecraft           13.
   Since    the general    Project  Mercury     training
                                                                        (See fig. 10-2.)
program      is common    knowledge    (see refs. 1 and                    A second      important                     activity      which              con-
2), this    discussion  is limited  to the specialized                  tributes  measurably       to                pilot    familiarity               with
training  activities which              were conducted sub-             the spacecraft      is 1)articipation,     as spacecraft
sequent  to the selection              of the crew for the              observer,  in the many systems          checks   (see figs.
MA-6 flight.                                                            10-3 and 10-4)        which constitute      the prepara-
                                                                        tion of the spacecraft       for flight.     This testing
             Spacecraft       Familiarization
                                                                        takes place both in the hangar         and on the launch
   At this stage of the Mercury     program,   each                     pad after     mating      of the launch-vehicle        and
spacecraft  differs somewhat    from its predeces-                      spacecraft.       A total of over 100 hours was spent
sors and a considerable     amount   of time must                       in the spacecraft     by the flight crew during  these
be devoted       to the study    of        these differences.           tests.
This study      was accomplished           in part by system                        Baseline   Physiological   Studies
briefings     conducted       by McDonnell         Aircraft
                                                                           I)uring the early phases                          of the training,               an
Corporation       and NASA       engineers     as shown in
                                                                        effort was made to acquire                          familiarity   with             the
figure    10-1.     Approximately         40 hours      were
                                                                        l)hysiological     sensai ions that might be expected
spent in formal      briefings   of this type.     Detailed
                                                                        dm'ing     the flight.
discussion      of environmental        control,   reaction
                                                                            At the Naval School        of Aviation  Medicine,
control,    automatic      stabilization       and control,
                                                                        Pensacola,          Fla..         the    flight      crew      received         a re-
sequential,    electrical,   I)yrotechnic,      comnmnica-
                                                                        fresher      course          in night             vision,     and      spent       pe-
tions,   and recovery       systems      were held in the
                                                                        riods in the slowly                     revolving           room      and      in the
crew quarters        by systems       engineem     and were
                                                                        human   disorientation                    device.
 attended by the flight         crew and        representatives
                                                                           Baseline         studies         of the pilot's            individual          bal-
 of the NASA   Manned           Spacecraft        Center Train-
                                                                        ance      mechanisms              were     made       at this time.               (See
 ing Division.
    In addition,       many    hours     of individual     study        figs.     10-5   and        10-6).          Since        an    important           ob-


                   /                   PRE_DING           p_          8LANK        _OT        FILMED
                                                                             Fmum:          10-3.--Astronaut                Glenn       dis_'usses          preparation
                                                                               activities         with      backup          Astronaut         Carpenter              during
                                                                               spacecraft          test      of    ei_vironmental            control         system.

Flot-a_    10-2.--Individual            study      by   Astronauts   Glenn
                               and   Carl)eater.

jective   of the flight was to evaluate       tile astro-
naut's tolerance     of prolonged    periods of weight-                      Fi(_v_         10--4.--Astronaut                Carpenter           enters            Mercury
lessness,   baselin_   st/idles  were conducted     in an                      spacecraft           13    during        a    preparation             test     in     hanger

attempt   to provide   data                for COml)arison  with in-           prior    t() MA-6          laun(.h.

formation     accumulated                    (iuri.g alld after  the
flight.      Th_ special             equipment,          which   was de-     90 hours in the procedures         trainer   during  which
velol)ed      for inflight            evaluation         of oriemati(m       complete     mi_ion     simulations,       both with and
ability,     is discussed            subsequently.                           without     range    support,     were practiced.       (See
                                                                             fig. 10-7.)     The_    ,_imulations     provided   experi-
                        Flight        Simulation                             ence in lhe performance         of all flight-plan    activ-
   The flight, crew spent                a total     of approximately        ities and familiarity       with range procedures.

FlOVRE      ]0-5.--Modified             caloric     test.         Astronaut's             bal-
  ance      mechanism           (semicircular           canals)         are     tested      by
  running       cool    water       into    ear   and       measuring           effect      on
  eye     motions        (nystagmus).

   Many   hours   were spent     practicing      manual
control of spacecraft   attitudes.      Emphasis     was
placed  on control    of the retrofire      maneuver,
turnaround     following      sustainer      engine   cutoff
(SECO),     and reaction        control    system   (RCS)
checks following     insertion.       Orbit maneuvering
with low thralsters    was also simulated.
   Additional     practice      in the manual      control
                                                                                                      FIGURE      lO-6.--Ataxia            test   : Checking        Astronaut        Glenn's
task was acquired         through    the u_ of the air-                                                 balance        mechanism           performance         by    his   walking       on     a
lubricated    free-attitude        (ALFA)     trainer      at                                           narrow         board.

Langley    Air Force Base, Va.
    System   failures in orbit which                                required im-
                                                                                                      provides    to evaluate     the pressure      suit in the
mediate    or end of orbit     reentries                              were prac-
                                                                                                      spacecraft     environment.       The    suit     restricts
ticed and discussed.
                                                                                                      mobility   considerably,    and       well as
   The majority       of trainer     time was devoted          to
                                                                                                      the special equipment        were designed       with this
launch aborts with the support            of Mercury       Con-
                                                                                                      limited mobility     in mind.
trol    Center    (MCC)       and      Bermuda        (BDA).
                                                                                                         These    simulations     were excellent       not only
Astronaut      Glenn     was subjected         to simulated
                                                                                                      from       the     training          standpoint,          but because              they
system      malfunctions         of    every     description.
Some of these,        with proper        corrective     action,
resulted     in continuation        of the mission        while
others       required            either     immediate               or fixed time
aborts.         These           aborts,      depending               on their  na-
ture, could be initiated       by either the Astronaut
or MCC, or both.
    Tape   recordings     of Astronaut     Glenn's     voice
were made        during    these trainer    sessions     and
sent to all range stations       so that flight control-
lers might     become familiar       with his voice and
normal      manner      of speaking.       In     addition,
physiological      and performance        data were re-
corded        for      postflight          comparison               with        onboard
   One        additional             function            of       the     procedures                     FI(_t_HE       lO-7.--Astronaut              Glenn      using      procedures

trainer        worthy            of note          is the          opportunity                    it                         trainer    for    simulated        mission.

   634401      0----62------8
stimulatedoriginal thinking that w_ range-                                       so devoted          and anything    much short            of this is
wideandmanyflight-planandmission-rule       in-                                  insufficient        to maintain  good physical           condition.
puts resulted.Muchwaslearned       both by the
astronautrod the flight-control
         '                      teams.  If one                                             Special      Observation        Requirements

activity    were to be singled out. as being                     the most            A 2-day period     was spent   at the Morehead
valuable     in preparing    for the flight,                     it would
                                                                                  Planetarium    in Chapel Hill, S.C.       This proved
be this procedures             training.                                          to be an invaluable    aid in familiarization     with
                                                                                 the heavens       in general   and particularly     with
                        Physical            Training
                                                                                 those constellations     and star patterns    that might
   Since    its inception,      the Mercury    physical                          reasonably     be visible through      the window     for
                                                                                 the MA-6 lamwh (late.          Meml)ers    of the More-
training    program      has been the option of the in-
dividual.      Astronaut     Glenn has elected to exer-                          head staff were most            cooperative  and continued
                                                                                 use of their facilities          is recommended.
cise   by   running.             (See        fig.   10-8.)      Over       the
                                                                                    Additional study  of the constellations                      was
                                                                                 aided by the use of a Farquahr  celestial                    sphere
                                                                                 and many      star charts,      astronomy     books, and
                                                                                 star finders.     A star chart,      which proved to be
                                                                                 not only a valuable       study aid but also a good
                                                                                 navigation    aid and darkside        yaw reference      de-
                    (     :        :                                             vice for infiight     use, was developed.
                                                                                    Two briefings.with        the Ad Hoc Committee
                                                                                 for Astronomical      Tasks for the Mercury         Astro-
                                                                                 nauts and with _ientists           of the Project    Mer-
                                                                                 cury Weather       Support,      Group    and the U.S.
                                                                                 Weather     Bureau   Meteorological       Satellite   Lab-
                                                                                 oratory    were held in Washington,       D.C., during
                                                                                 which observations        of interest to both agencies
                                                                                 were discussed.       I)evelopment    of special equip-
                                                                                 ment resulted      from these discussions,     also, and
                                                                                 is covered    in the next section.

                                                                                                       Special     Equipment

                                                                                    As a result of the preflight  briefings,  the need
                                                                                 for some special equipment      was apparent,     and
                                                                                 r_ container   for this equipment        was needed.
                                                                                 Following       are    brief    descriptions      of this    equip-
                                                                                    Two      economy-type             toothpaste      tubes     were
                                                                                  filled separately      with applesauce        and beef stew.
                                                                                 A screw-on       straw which punctured            the seal on
                                                                                 the top of the tube was provided             to duct. the food
  FROURE    10-8.--Astronaut                Glenn      during   physical
                                                                                 over the lip of the hehnet              to the mouth.
                                                                                      The pill tube held 10 pills and was spring-
last 3-year period, he has steadily       built up from                          loaded    for easy extraction         of the pills.       Each
1 mile to 5 miles a day.        For the 3 months      pre-                       ])ill measured       about   3/_ inch thick      and 3/_ inch
ceding    the flight, he ran 5 miles nearly         every                        in diameter.         Nine of the pills were chocolate
(lay, except for the final week when he tapered                                  malt tal)lets     and the other was made of xylose
off to '2 miles, I mile and then '2 days of complete                             which is '_ five-carl)on;       traceable     form of sugar
rest prior to the flight.                                                        and was in('luded        to measure       the rate at which
   Tiffs activity,    including  dressing   and shower-                          the intestine    absorbs food         during weightlessness.
ing, required      about 1 hour per (lay.       It is felt                          Pliers     were    in('lu(led        to facilitate    egress
that this is a reasonable       amount    of time to be                          through     the top of the spacecraft             if the pip pins


                                                                                                      h]IACK      h,_:)WHIT£            PHOTOG'RAPN
on the parachute     canister     became              jammed    or       per arm.     Accessibility was not good but it was
in the event of a survival    situation              where pliers        the only space available.     Use of the equipment
have no substitute.                                                      was further     hampered    by the need for a re-
  The bulb block contained    extra amber,   green,                      straining   line to each item which was secured
and red bulbs to be used in the event of telelight                       to the accessory    kit. Velcro,   a trade name for
or warning-light          bulb failure.                                  an adhering    material  made up of two types of
  The waterproof             bag was provided            for      film   cloth, one with multiple     loops, one with multi-
stowage    after    landing   and before     recovery.                   ple hooks which adhere          when pressed     together,
   The camera       filter was provided    for use with                  was used extensively        inside the spacecraft        for
the infrared     fihn and was to be mounted         inside               restraining     the kit contents    during    flight.      In
the cament     when the infrared      fihn was used.                     paper     12, Astronaut    Glenn discusses     the use of
   Extra     film was         carried    for the   regular       cam-    this equipment.
era;   only the one roll of ultraviolet           film al-                  In addition      to this equipment      in the acces-
 ready in the ultraviolet      camera was carried.                       sory kit, a knee pad, knife,       scissors,   survival
    The ultraviolet    spectrograph    consisting     of a               kit, flashlight, star charts,   and an orbital     chart
35-ram    camera    equipped     with a special quartz                   book with an overlay         of worldwide      weather
                                                                         were carried.
lens and prism system          was developed     for use
through     the spacecraft    window    in the 2,000 to                     A discussion     of this equipment      is pertinent
3,000     angstrom      wavelength     band.     A   de-                 to the astronaut     preparation    phase because not
mountable      reticle was provided    for sighting   on                 only was a great       amount    of time spent in the
the star.                                                                development     and modification     of the equipment
    A 85-mm camera with a 50-trim F2.8 lens and                          but a like period was involved       in becoming     pro-
   photocell      which automatically     adjusted   the F               ficient in its use.
stop was used for daylight         photography.       Con-
siderable       development    effort   was required     to                           Egress        and   Recovery         Practice
modify       the camera     for use in the spacecraft
                                                                             Much time had been spent in egress training
by the astronaut      in a pressure  suit.                               prior    to the crew selection        and little remained
   The airglow      filter is a device     which               filters   to do but polish the procedures.
out all light    except    the 5,577 angstrom                  wave-
                                                                             Egress    from the small end and side hatch of
length,    one of the bright       lines of the airglow                  the spacecraft        was practiced       with both tIUS
spectrum.       It was intended      to be used as an aid                 (see fig. 10-9) and IIR_S            (see fig. 10-10)    hel-
 in studying    the patterning     of the airglow    layer.              icopters    at Langley       Air Force Base, Va.
    The binoculars      were of a miniature       type, 8-                   Egress     was practiced        by other    members      of
 power with 50-mm objectives.                                            the astronaut       team with a destroyer           (see fig.
    The filter block was provided         for use with the                10-11) out of Norfolk,           Va., and they reported
 V-Meter.      It allowed      all the normal     exterior
                                                                         no problems.
observations     to be made while excluding        all but                   At Cape Canaveral,          Fla., two 3-hour periods
red, green, or blue light.                                                were spent with the LARC              amphibious     vehicle
    The V-Meter      is a very clever little instrument                   in deep-water      familiarization       with the liferaft
whose assigned        name is the extinctospectropo-                      and survival     equipment.         Many equipment       and
lariseope    - oceulogyrogravoadaptometer.            This
                                                                         packing   lnodifieations            resulted from this work.
device is designed      to be used for 16 astronomical
                                                                            Pad egress practice             was accomplished   at Cape
and physiological     tests.  It could be used for
                                                                         Canaveral          utilizing      the    Midas     Tower        (see     fig.
measuring      the  relative    brightness     of     the
                                                                         10-1!2)      and     the    Ml13        armored      vehicle.          This
zodiacal  light and other dim night phenomena.
                                                                         practice      acquainted         all launch       complex       person-
It was equipped      with crossed     polaroid    filte_
which permitted    direct viewing of the solar disc                      nel   with     the     problems         related     to egress          from
and measurement        of the polarization      of the                   the spacecraft          with     the    launch    vehicle     in an un-
corona.    It could also be used to judge the hori-                      safe condition.
 zontal    under     zero-g     conditions.                                  A form of egress training                     was conducted    at
    All    of this     equipment         was   carried   in an ac-       t he end of each trainer session                  by going through
 cessory    kit    located      by the astronaut's       right     up-   the   actual       sequence        of events       from      parachute

 deploymento actual egress. This practice
 helpedto smooththe existingprocedures s
 wellastodevelop ewones.

FIGURE        10-9.--HUS              helicopter          lifting         astronaut       from
               spacecraft,           side    hatch      egress      practice.

                                                                                                   FmUR_     10-11.--U.S.        destroyer      lifting         spacecraft      from
                                                                                                     water    with    standard       boat    davits       and      special    lifting

                                                                                                   categories.         A considerable             amount            of time      was
                                                                                                   spent on :
                                                                                                      (1) St_r        recognition
                                                                                                      (2)  Morse code practice
                                                                                                      (3)  Study of aerial photographs
                                                                                                      (4)  Study of world charts
                                                                                                      (5)  Study   of Tiros photographs
                                                                                                      (6)  Study    of photographs      from                             previous
                                                                                                              Mercu W flights
                                                                                                      (:7) Study   of mission     rules
FI(¢URE       10-10.--HR2S                helicopter          preparing          to   remove          (8) Study of Atlas systems
 astronaut         from        floating        _'pacecraft,         egress        practice.
                                                                                                      (9) Attending     briefings
                                                                                                      (10) Physical    examinations
                                    Miscellaneous                                                     (11)    Correction          of minor            pressure-suit            diffi-
   Many         other         studies         were       conducted              which         do      Because        of the many delays                    which preceded
not    fall      into        ally     of the           previously             mentioned            the launch        of MA 6, it was felt                 in some quarters

                                                                                                           that Astronaut Glenn was overtrained.     On the
                                                                                                           contrary,   there was easily enough work to fill
                                                                                                           the available     preflight period. During   the
                                                                                                           many delays, he continued to train, modify and
                                                                                                           practice procedures, and work with and modify
                                                                                                           the accessory equipment.
                                                                                                             Training   data indicated continued                                              improve-
                                                                                                           ment up to the day of launch.
                                                                                                              The backup astronaut's        role throughout    was
                                                                                                           to participate      in as much of the training       ac-
                                                                                                           tivity as was consistent         with tim astronaut's
                                                                                                           need for direct support         and the need for an
                                                                                                           astronaut as spacecraft observer during system
                                                                                                           tests.   Knowing       what is involved in this job,
                                                                                                           it is difficult to envision mission accomplish-
                                                                                                           ment in a comparable         amount of time, without
                                                                                                           the services of a backup pilot.
                                                                                                               The training      period in general      went very
                                                                                                           smoothly.        Cooperation   was the keynote.       A
                                                                                                           few blind alleys were stumbled into but a siz-
                                                                                                           able extension was made to the trail started by
                                                                                                           Astronauts      Shepard and Grissom.        It is hoped
     1                                                                                                     that through our efforts, the way for the many
Fioulm        10-12.--Astronaut                practicing            pad     egress          with
                                                                                                           who will follow in Astronaut         Glenn's footsteps
                             aid     of egress      tower.                                                  will be a little easier.


1.   SLAYT01_',        DO.'_ALD       K. : Pilot          Training           and      Preflight         Preparation.              Prec.      Conf.         on    Results     of        the    First       U.S.
         Manned         Suborbital         Space      Flight,         NASA,           Nat.      Inst.   Health,        and      Nat.      Acad.    Sci.,        June   6, 1961,         pp.   53---60.
2.   VoAs,        R.   B. : Project        Mercury:             Astronaut             Training          Program.             Physcophysiological                   Aspects        of     Space        Flight,
         Columbia         Univ.       Press,       Jan.      1961,         pp.     96-116.

                                          11.         PILOT         PERFORMANCE

By WARREN J. NORTH, Chie], Flight Crew Operations Division, NASA Manned Spacecra]t Center; HAROLD
    I. JOHNSON, Flight Crew Operations   Division, NASA Manned SpacecraJt Center; HELMUT A. KUEHNEL,
    Flight Crew Operations   Division, NASA Manned Spacecra#   Center; and JOHN J. VAN BOCKEL,  Flight
    Crew Operations Division, NASA Manned Spacecra#     Center

                             Summary                                     Fin,ally, the performance         of Shepard,   Gris-
                                                                       _m,    and Glenn    during    their   Mercury   flights
   The   MA-6       flight    showed    that    man    call adapt      wouhl _em     to justify   the selection     of mature
to spacecr,_ft      activities     in a space environment              and      exl>erienced             aircraft     test pilots        as Mercul 3"
ill much the same way as he adapts                 to his first        astronauts.
flight in a new airplane.
    The value of static           and dynamic      simulators                                            Introduction
in providing        accurate       spacecraft   systems     and
control    familiarization         was reaffirmed.      Nearly             The l)ilot.'s l)rimary      role during    the MA-6
all phases     of the MA-6           flight had been simu-             flight was to ohserve        and report     on spacecraft
lated.    Although        Glenn previously       experienced           systems   operation       and provide     control   inputs
zero-gravity        flight     for durations       of only      1      which   would       insure    mission    success.    Addi-

minute     in parabolic       aircraft      flight paths,       the    tional        activities         were    included        in the flight       plan
extension     of weightlessness        to 41/_ hours caused            to obtain      information        on visibility        conditions
no concern and was, in fact, a pleasant                  contrast      during      both     day and       night,      to obtain         pic-
'lfter spending       several   hours on his back at lg.               tures   with     sl)eci,_l photographic            fihn, and to
    Proposed     concepts     for m,tnual       control    of ad-      obtain     physiological      information.          These addi-
 vanced     spacecraft      and    launch       vehicles      were     tional activities      were to be conducted            only if the
_ziven added       impetus     as a result       of the pilot's        spacecraft       were operating           satisfactorily         and
findings_.     By giving       man a major role in sys-                did not require        full attention       from the pilot.
tems operation,        as in aircraft     practice,     the most          In formulating          the detailed         flight     plan,     a
 rapid and efficient attainment            of advanced        mis-     prime         consideration             was the        orbital    position      of
sions will be possible.           The possible         malfunc-        the sl)aeecraft     with respect to the ground       track-
 tion of the MA-6 heat-shield            release mechanism             ing and       communications         stations.    It    was
required     the pilot    to interrupt       the automatic             plammd     to perform       most of the spacecraft      ma-
retropaekage     jettison    sequence.      The automatic              neuvers     witlfin    line-of-sight     distance   of the
control   mode was similarly           switched    off when            gromld stations   in order t hat spaceeraft                            mot ions
the small attitude        control   jets malfunctioned.                couhl be correhtted     between   the pilot                            and the
The significance     of these malfunctions        and man-             ground          readout          of UHF        radio     telemetry.        As to
ual corrective     measures      can be extrapolated       to          he expected                on a flight of              this nature,    radio-
the desi,-m and operational         philosophy     for high-           voice contact               was maintained                a great   majority
ly-complex      muttistalze    missions     of the future.
                                                                       of tim time            (al)l)roximately                80 percent).
It, is clear that man must phty an integral               role.
                                                                           Although    the spacing     of Mercury     network
   His ability      to observe    the separated       launch
                                                                       stations     was designed    such that     the longest
vehicle equally      well when it. was either above or
                                                                       void in UIIF       radio contact   would    be 17 min-
below the horizon,         his ability    to view the sun
                                                                       utes     in a three-orbit               mission,        during     the MA-6
safely    in space,    and his ability       to establish       a
yaw reference        optically   lends credence        to         mission          tim longest            flap   in effective       voice      com-
use of optical     rendezvous     techniques     in Gemini             munications                was     9 minutes,          13 seconds,        al)par-
and Apollo      missions.                                              ently         due    to     the     longer       range       of   HF       radio.

                                       PRE DING    B
                                                       I                                                                                             113

                       Ge/--LL 'NrrNrm
This period of           radio silence     occurred           during            quential   events and providing     manual    override
the   third   orbit     between   Australia     and          Hawaii.            when necessary.      Most of the spacecraft       flight
                                                                                events can be identified    by instrumentation        on
                      Pilot   Performance
                                                                                the control   panel.   In this flight, as well as in
   Although     network     communications      were ex-                        the previous     two manned     ballistic    flights, tile
cellent during    tile flight, it was apparent     ill the                      pilot's filut and most reliable   indication      was the
Mercury     Control    Center    that the pilot was the                         actual   visual     observation     and/or    an auditory
only    person    with    continuous     knowledge      of                      cue of the event and/or          a corresponding       accel-
spacecraft     systems,     and he was therefore        in the                  eration   from the event.       Therefore,    the pilot has
best position     to exerci_    control of the flight.       It                 positive    evidence    of the occurrence      of an event
is significant       that even during        the period      in                 by direct         cues without      the            dependence         upon
which he was assessing           the control     system and                     electronic       equipment.
the apparent        heat-shield    malfunctions,       he was                      Because        of tile malfunction               of the     automatic
able to continue            detailed   systems          reporting,              control      jets,     the pilot  was on manual    control
make and record           visual obsel_.ations         of weather               during       most      of the last two orbits.  The deci-
and astronomical       phenomena,      and take many                            sion to retain the retrorc<'ket     package    required
photographs.                                                                    that tim automatic    retrojettison     switch   be left
    One of the mlportant      pilot tasks was moni-                             in the "off" position   after retrofire.      The "off"
toring   the occurrence    of critical   spacecraft se-                         position      of this            switch   electrically       interrupted

                                     FIGtrRE   ll-1.--MA-6         instrument       panel,    left    section.


                                                                                                     131../_K         AND      q_,:_ITE      p_-kOTOG'_AP-I'_
                                        I_OUaE 11-2.--MA-6      instrument     panel, center section.

the sequential      system    and       made     it necessary   for                        Control        Systems         Check
the pilot     to control    manually  certain events
                                                                           A control   systems      check was performed        dur-
from that      time through    the end of the flight.
                                                                        ing the first orbit        to verify     the operational
Those evl_nts were: to retain retrorocket                   pack-       status   of the     reaction     control    modes     in a
age, to pitch to reentry          attitude,      to retract    the      mininmm      amount      of time and with minimal
periscope,     to actuate    0.05g r_nt_ T relay, and to
                                                                        fuel usage.    Figures    11-1 and 11-2 show the
extend      the peri_ol)e.        The rescue          aids were
                                                                        portions  of the instrument    panel which ,ire in-
deployed       manually     after impact        in accordance
                                                                        volved during    the control  systems check.   The
with normal       procedures.
                                                                        large      vertically-oriented             handles       on the left
   In each ease of manual              control     of an event.,
                                                                        _ction      are used to control             valves     in the hydro-
the pilot took the appropriate                 action    and ob-
                                                                        gen peroxide           i)lumbing  system.    The              horizontai
tained     the desired    result.
                                                                        switch array           is used to select various               electronic
    The general    ability of the pilot to control       the
                                                                        control        modes.         Spacecraft       rate     and      attitude
vehicle manually       is illust rated by a brief review
                                                                        displays        are.    shown      in tile     upper        portion         of.
of the major     art itude nlaneuvers      acc<)ml)lished.
With the exception        of the 180 ° yaw luwiaroun(1,                 figure     11-2.        The    control     system      is designmd          so
the    following     maneuvers        were   required      to           that     the   automatic         and     manual       systems      can be
assess the status of the contro] system l)rol)erly                      used       independently            or     concurrently.            Many
and to accomplish       the mission :                                   addMonal           control      combinations          are   possible        in

                                    -       ,-     ?
      PITCH               0                     v

 ATTITUDE,          -20                                                  j_TRAAINER       RUNS
       DEG          -40       _e     t         J      ,        i

                     40 [                      /'X                           _     INFLIGHT           lOG
     YAW                 20 t              Y           X             _           ATT TUDE
 ATTITUDE,                0                         ----                 "

    ROLL                 2i
                         4                                                                                        ...... __                         _.....___._ PITCH
     DEG                      L_     L       _ ..... L__            -_         _LT
                     -I00                  I:00         2:00                 5:00                          :53                     1:55        I:57                                   I:59
                                   TIME,       MINUTES:SECONDS                                                                 TiME FROM LWT-OFF, HR:MIN

 FIGURE       ll-3.--MA-6                manual           control        systems      check.          FIGURE         11--4.--MA-6              180 ° turnaround              maneuver.

that the m,mua]    system can be used to control                                                 180 ° yaw turnaround,         using the window,           while
motions  abou! ()lie axis and the automatic    sys-                                              holding    pitch and roll I_asonably           steady as can
tem to comm,md      motions  about the remaining                                                 be _en in figure     11-4.
two      axes.                                                                                      These    maneuvers      involving      large    deviations
    Figure    11-3 illustr,ttes     tile inflight    control                                     from nomn'd spacecraft          attitudes     produce     spur-
systems check wit h a l)a('kground           envelope    con-                                    ious    indications    from      the     horizon     _anner-
sisting    of four control      systems    checks accom-                                         gyroscope             reference           system.            In      each      case,        the
plished    on the                  procedures   _rainer.  All space-                             l)ilot     noted             the    erroneous              indication            and        re-
craft   attitudes                   are defined   as zero when the                               erected      his gyroscopes                     within      the limits          required
pilot is sitting     upright     with the small end of                                           to allow          the        automatic            1_ference           system          to re-
the spacecraft      pointing     horizontally     })a('kward                                     store     the        I)roper           indication.                A similar           gyro-
along   the flight     path.      .ks ('an lie seen from                                         scope caging                  operation            is neces_sary            to correct
this figure, tile art itudes between          the flight and                                     aircraft gyro                precession           after a gross             maneuver.
procedures     trainer    varied     10 ° or less, the rates
varied   less than 1 ° per second.           The time used                                                                      Retrofire               Control
to complete    the flight  maneuver    was almost
identical   to those  on the 1)rocedures   trainer.                                                 The          pilot barked               up the automatic                       control
These inflight  data may give the initial   impre.a-                                             system          during   the             retrose<tuenee and                     retrofire
sion of a poorly controlled  maneuver:    however,                                               events,         using the mamml proportional                                   control
it should   be remembered    that  during    orbital                                             tootle.         The at tit
                                                                                                                          utles (lid not deviate                             more than
flight, the spacecraft       has no aerodynamic      stabil-                                     3 ° during               this       maneuver.                It      is    difficult         to
izing for('es or aerodynamic          (l'tml)in _. Except                                        evalu.tte          the       effe(:l     of      the     pilot      control          during.
for retrofire,    there    is no need to control     space-                                      retrofire          because             ,)f concurrent               activity         of the
craft   attitudes    precisely;    consequently,    during                                       automatic             and manual                  control          jets.
these maneuvers        the pilot was looking for quali-
t alive rather    t ha n quantitative      results.                                                                    Reentry             Pitch          Maneuver

                   180 ° Right                      Yaw       Maneuver                               IIe manually                   positioned            the sl)acecraft              to the
                                                                                                 l)roper         reentry            attitude              (0 ° 'lbout           all     axes)
      The        pilot        made         three           1_0 ° yaw             maneuvers
                                                                                                 using the ,mmual ('ontrol                           mode and the ]'ate and
during     this flight;   however,  only the first was
                                                                                                 attitude   instruments.                            The   preci_    reentry
intended      as a l)lanned   maneuver     in which tile
                                                                                                 pitch      alinement               is 1.6 °.           As can be _en                 by fig-
pitch    and     roll errors   were minimized.      The
other    two 180 ° maneuvers       wet_ _, done for the                                          ure 11-5,           he l)erform(_                 this maneuver                smoothly
l)url)o_,  of obsem, ing and taking     l)ict ures of the                                        :m(l      accurately.                  The       initial         conditions           repre-
sunri_,   and the l)articles surrounding       the space-                                        sent      Sl)acecraft              'tltitu(le          at the      end     of retrofire
craft.    He had no difficulty    making      the precise                                        in which              the       pitch         angle        was      -34: ° .

                                                                                                                          Pilot    Observations
                                                                                                         In general,   the pilo_ found    he could  easily
       20 r
                                                                                                      orient the spacecraft    in pitch and roll by using
       IO'                                                                                            the external   horizon  reference.
             I                               YAWq          f    _ --    "" -_.
        O_ .....                             __ _ -/                       _--_-                         Yaw      (or drift)      is nmre    difficult     to determine

                                              / ....                                                  at orbital     attitudes
                                                                                                      tures 'rod clouds subtend
                                                                                                                               because ground
                                                                                                                                       low angular
                                                                                                                                                    terrain   fea-
                                                                                                                                                       rates witl_
   -20'                                     /_ PffCH                                                  respect    to the spacecraft.        By the end of the
    -50                                 /
                                    /                                                                 flight, he was able to determine        yaw quite easily,
                                                                                                ]     both on the da.ylight       side and during     full moon-
   _40L___-'----                   L         _                             l       _     __.
        04:59                    04:40      04:41   J  04:42                                  o4m3
                                                                                                      light    night, conditions,      by using    the window
                                TIME FROM LIFT-OFF, HR:MIN
                                                                                                      reference.        During  the flight, he used the pro-
          FIeURz        ll-5.--MA-6                  reentry      pitch     maneuver.
                                                                                                      eedure      of pitching       down      to -60 ° to pick            up
                                                                                                      terrain      drift  due     to the     orbital velocity.            He
                                  Reentry             Damping
                                                                                                      found tlmt the peri_ope      was not as useful as the
      The          shal)e         and        weight            distribution             of     tile   window   for deterlnining     drift on the nightside.
Mercury      sl)acecraft     provide    sufficient                                   inherent         Even with a full moon, the clouds were too dim
aerodynantic       stability    to reenter     with                                  the con-         in the l)eri_ope     to pick up readily     a specific
trol      system                inoperative;              in fact,         the     Mercury            point and follow      it for yaw heading     informa-
"Big         Joe"      development                   flight      in September                1959     t ion.

did reenter                successfully               with       an inactive           control           The pilot was able to observe   the separated
                                                                                                      htunch  vehicle clearly when it was both above
system.               Consequently,                    the thrust           levels      of the
                                                                                                      and below the horizon.     Direct observation    of
reaction-jet                control           systenl          were       desigmed           witl_
                                                                                                      the sun through    the window      was no more annoy-
sufficient            capability                  to control           spacecraft.           'ttti-
                                                                                                      ing than    direct  observations     from tile surface
tudes            during    retrofire,               but not to control space-                         of the earth.
craft,           trim   attitudes                  during  the high aerody-                              Jolm Glenn describes       these and other ob_rva-
nan-fie           forces          of    reent W.               The      pilot's        reentry
                                                                                                      tions fully in paper 1'2.
task         was      to aline              the     spacecraft            initially          with         He found     that    weightlessness     was pleasant,
the       velocity              vector,       then       to damp               or minimize            and in several respects,        easier or more enjoyable
the          low-frequency                        oscillations            which          occur.       than the lg condition.            Zero-g  facilitated     cer-
Although       his attention         was diverted         by the                                      tain tasks, such as using the camera,              since this
bm'ning     retropack,       reentry     damping       was per-                                       equipment     could be left hanging       in midair      when
 formed satisfactorily         by using a cmnbination           of                                    he was intermlpted           by other    activities.      The
the manual      and automatic         control    systems mltil                                        pilot ext)erieneed       no i)roblem     in i,.aching      for
the control     fuel was depleted.                                                                    and activating        controls.      The effects      of head
    In contrast     to the MA-5          mission,     there was                                       rotation   in a zero-g field were invest igatext.          He
little  concern       regarding        the    ability     of the                                      moved        his head rapidly           in each of         the three
manned      MA-6        spacecraft       to complete        three                                     planes      of rotat ion, with        no sensations        of nausea
orbits.    In fact, the third orbit gave the pilot                                                    or vertigo.    The pilot    reported    that he could
additional   time to experiment      with the mal-                                                    feel only the highest    angular     accelerations  en-
functioning    control system     in order     that he                                                countered   (luring  the flight.     Most of the atti-
could better   perform  a successful   retrofire   and                                                tude maneuvers      were conducted      at rates lower
reentry.                                                                                              than      those   that    could   be sensed        under    lg.

                                         12.    PILOT'S               FLIGHT               REPORT

                       By JOHN H. GLEr_,               Jr., Astronaut,     NASA          Manned       Spacecra/t     Center

                            Summary                                            The      technicians       and      I had     been    through    the
                                                                               entry to the spacecraft  many times.
   Weightless  flight was quickly adapted   to, and
                                                                                  As with every countdown,       short delays   were
was found to be pleasant     and without   discom-
fort,.  The   chances    of mission   success    are                           encountered    when problems      arose.   The sup-
                                                                               port, for tim microphone    [n the helmet,    an item
greatly     enhanced     by the presence      of a huma_n
                                                                               that    had been moved     and adjusted                    literally
crew in the spacecraft,.         A human     crew is vital
                                                                               thousands    of times, broke and had                     to be re-
to future      space    missions    for the purpose      of
                                                                               placed.    While the spacecraft  hatch                   was being
intelligent     observation      and actions    when the
                                                                               secured,   a bolt was broken     and had to be re-
spacecraft,      encounters   expected          or     unexpected
                                                                               paired.    During   this time I was busy going over
occurrences       or phenomena.
                                                                               my checklist    and monitoring    the spacecraft in-
                        Introduction                                           struments.

    The test objectives     for the MA-6  mission  of                              Many people were concerned         about my mental
Friendship     7, as quoted     from the Mission  Di-                          state during    this and earlier delays, which are a
rective,   were as follows:                                                    part of preparation      for a manned         space flight.
                                                                               People    have repeatedly      asked whether          I was
   (1)   Evaluate     the performance                  of a man-
                                                                               afraid   before     the mission.       Humans       always
           spacecraft     system   in           a       three-orbit
           mission                                                             have fear of an unknown        situation--this       is nor-

   (2)   Evaluate    the       effects    of   space     flight     on         mal.     The important     thing is what we do about
           the astronaut                                                       it.   If fear is permitted     to become a paralyzing
   (3)  Obtain    the astronaut's       opinions     on the                    thing   that   interferes   with proper   action,   then
                                                                               it is harmful.        The best antidote  to fear is to
          operational    suitability       of the space-
                                                                               know all we can about a situation.            It is lack
          craft     and  supporting          systems     for
          manned space flight                                                  of knowledge     which often misleads         people when
   These are obviously      broad      objectives.     Pre-                    they try to imagine      the feelings     of an astronaut
vious papers     have described      in some detail      the                   about to launch.       During    the years of prepara-
                                                                               tion for Project,     Mercury,      the unknown       areas
operation   of the spacecraft        systems  and, to a
                                                                               have been shrunk,      we feel, to an acceptable      level.
degree,   man's   integration      with these systems.
                                                                               For those who have not had the advantage                  of
   My report    is concerned        mainly   with those
items in all three      objectives     where  man's  ob-                       this training,   the unknowns          appear    huge and
                                                                               insurmountable,     and the level of confidence           of
servation     capabilities     provided     information      not
                                                                               the uninformed       is lowered      by an appropriate
atlained     by other means.          It is in this type of
reporting      that     a nmnned        vehicle   provides       a
                                                                                  All    the   members       of the        Mercury    team     have
great     advantage        over an unmanned             vehicle,
which is often deaf and hlind to the new and                                   been working       towards     this space flight oppor-
the unexpected.             My report,  then,          will stress             tunity   for a long time.         We have not. dreaded
what I heard,        saw,    and felt during           the orbital             it ;we have looked forward          to it. After     3 years
flight.                                                                        we cannot be unduly         concerned     by a few delays.
                                                                               The important       consideration      is that everything
              Preparation       and      Countdown                             be ready,    that nothing      be jeopardized      by haste
   Preparation,       transfer  to the launch pad, and                         which can be l)re_rved            by prudent     action.
insertion    into   the spacecraft    went as planned.                             The initial   unusual    experience     of the mission

                    ,/,-,7 /              ,   PR$Of::_NG              P/IK._      12LANK         NO i     FILM_iD
           EAGt_ .//_ltl              ILtIIIONALI.X BLAIql
is that of beingon top of the Atlas launchve-                      tisoned.    I saw a flash of smoke               out the     window
hicle after the gantry h'ts t)eenpulled back.                      and thought      at first that the escape tower had
Throughthe periscope,   muchof ('al)eCanav-                        jettisoned  earl), and so reported,       tIowever,   this
eral can be seen.       If you    move      hack   and   forth     flash was apparently         deflected   smoke    coming
in the couch, you can feel the entire           vehicle            up around    the Sl)aeecraft      from the booster en-
moving    very slightly.     When     the engines    are           gines which had just separated.          The tower was
gimbaled,    you can feel the vile'at hm. When the                 jettisoned  at 2 mhmtes,      33.,_ seconds,   and I cor-
tank is filled with liquid oxygen, Ihe Sl)aeeeraft                 rected my earlier    report.      I          was ready to back
vibrates   and shudders    as the metal skin flexes.               up the automatic       sequencing               system     if it did
Through      the window   and       pcris,'ol)e     the white      not. perform   correctly     and             counted      down    the
plume     of the lox (liquid        oxygen)        venting    is   seconds to the time for tower                jettisoning.      I was
visil)le.                                                          looking at the nozzles of the               tower rockets when
                         Launch                                    they fired.    A large  cloud               of smoke       came out
                                                                   but little flame.   The tower               accelerated      rapidly
  When      the   countdown       reached     zero,   I could
                                                                   from    the sl)ace('raft    in a straight      line.    I
feel the engines    start. The spacecraft   shook,
                                                                   watched    it to a distance       of apl)roximately
not violently   t)ut very solidly.  There  was no
                                                                   1_ mile.    The spa('ecraft     was programmed         to
doubt+ when lift-off occurred.     When the Atlas
                                                                   l)itch down slowly just prior to jettisoning         the
was released   there  was an immediate    gentle
                                                                   tower and this m'meuver       provided    my first real
surge that let you know you were on your way.                      view of the horizon      and clouds.      I could just
The roll to the correct  azimuth was noticeable
                                                                   see clouds and the horizon      behind   the tower as
after     lift-off.   I had preset the little        window        it jettisoned.
mirror       to watch the ground.      I glanced    up after          After the       tower    fired,     _he, spacecraft        pitched
lift-off      and   could    see the    horizon     turning.
                                                                   slowly up again and I lost sight of the horizon.
Some vibration         occurred   immediately     after lift-
                                                                   I remember    making     a comment    at about    this
off.     It smoothed      out after  about     10 to 15 sec-
                                                                   time that the sky was very black.      The accerela-
onds of flight   but never          completely     stopped.
                                                                   at}on built up again, but as before, acceleration
There was still a notieeal)le        amount    of vibration
                                                                   was not a major     problem.    I could commmfi-
that continued    up to the time the spacecraft
                                                                   cate    well, up   to    the  maximum       of    7.7g
passed   through    the maximum      aerodynamic
                                                                   at insertion   when the sustainer-engine       thrust
pl_ssure    or maximum      q, at approximately                    terminates.
T+ 1 minute.     The approach    of maxinmm     q is
                                                                       Just before     the end of powered    flight, there
signaled   by more intense vibrations.           Fmx.e on          was one experience         I was not expecting.       At
the outside    of the spacecraft      was calculated      at       this time the fuel and lox tanks         were getting
982 pounds per square        fo_)t at this time.      I)ur-        empty      and apparently     the Atl'Isbecomes     con-
ing this period, I was conscious        of a dull muffled          siderably     more flexible than when filled.     I had
roar from the engines.         Beyond    the high q area           the sensation     of being out on the end of a spring-
the vibration     smoothed     out noticeably.       How-          board     and could fee] os(.illating   motions    as if
ever, the spacecraft       never   became     completely           the nose of the launch vehicle were waving         back
vibration   free during powered       flight.
                                                                   and forth slightly.       (Appendix    B presents                   the
    The acceleration       buildup    was noticeable  but          onboard     tape transcript     of the Friendship                         7
not bothersome.         Before     the flight my backup            ort)ital flight.)
pilot, Astronaut       Scott Carpenter,       had said he
thought    it would     feel good to go in a straight-                                Insertion         into    Orbit
line acceleration      rather    than just in circles   as
                                                                      The noise also incre_used    as the velficle    ap-
we had in the centrifuge      and he was right.
                                                                   proached    SECO     (sustainer    engine    cutoff).
Booster engine cut-off occurred at 2 nlinutes  9.6
seconds after lift-off. As the two outboard   en-                  When the sustainer    engine cutoff at 5 minutes,
                                                                   1.4 seconds   and the acceleration      dropped       to
gines    shut down      and were detaehed,             the ac-
celeration   dropped     but not as sharply           as I had     zero, I had a slight   .sensation  of tumbling  for-
                                                                   ward.   The astronauts    have often had a similar
anticipated.      Instead,    it decayed   over approxi-
mately     1/_ second.     There   is a change   in noise          sensation     during        training        on   the      eenlrifuge.
level and vibration        when these engines     are jet-         The    sensation      was    much       less during        the flight,

and sincethe spacecraftdid pitch down at                                the precision    with which       the test progressed.
this point,it, mayhavebeenstresultof actual                             It is quite an intricate     check.      With  your right
movement  rathertban an illusion.                                       hand you move the control           stick, operating   the
     There     was no doubt       when        the clam 1) ring    be-   hydrogen    peroxide    thrusters     to move the space-
tween    the Atlas     and the Mercury       spacecraft                 craft  in roll, 1)itch, and yaw.          With   your left
fired.    There    was a loud      report   and I im-                   band     you switch     from     one c_ntrol   system     to
mediately    felt the force of the posigrade     rockets                another    as the sl)acecraft     is manually  controlled
which sel)arate     the spacecraft    from the launch                   to a nmnber      of precise rates and attitudes.
vehicle.     Prior   to the flight    I had imagined                       This experience      was the t_rst time I had been
that   the acceleration     from    tbe_se three   small                in complete      nmnual      control,   and it was very
rockets        would     be   insignificant         and    that   we    reassuring     to see not only the spacecraft         react
might   fail to sense t'hem entirely,      but there is                 as expected,   t)ut also to see that my own ability
no doubt when they fire.                                                to control   was as we had hoped.
   Immediately     after _paration     from the Atlas,                     Following    this controls  check I went back to
the autopilot     started   to tunx     the spacecraft                  autopilot      control    and the spacecraft    operated
around.     As the spacecraft      came around    to its                properly      on autopilot   throughout   the first orbit.
normal       aft viewing        attitude,     I could   see the
                                                                                             Thruster        Problem
Atlas through          the window.          At the time I esti-
mated      that it. was % couple of hundred               yards             Because    of a malfunction       in a low-torque
away."         After     the flight       an analysis    of the         thruster    at tim end of tile first orbit, it was nec-
trajectory       dat;_ showed         that the distance      be-        essary    to control  the spacecraft      manually     for
tween      tim launch        vehicle      and the st)acec.raft          the last two orbits.      This     requirement     intro-
should, at this l)oint, be 600 feet.              Close enough          duced     no serious     problems,   and actually      pro-
for a rough          estimate.       I do not claim that        I       vided me with an ol)portunity            to demonstrate
can normally    judge     distance   so clo_.     There                 what a man can do in controlling            a spacecraft.
was a large sized luck factor        in the estimate;                   tlowever,    it limited    the time that could be spent
nevertheles'%  the facts      do give an indication                     on ninny of the experiments             I had hoped       to
that man can make an adequate            judgment      at,              carry out during       the flight.
lemst of short   distances     to a known     object   in
                                                                                                  Flight     Plan
space.        This capability   will be             important      in
future        missions in which     man             will wanl.     to
                                                                           The Mercury       flight plan during         the first orbit
achieve    rendezvous,,   since                 the   pilot     will    was to maintain          optimum        spacecraft      attitude
be counted     on to perform                   the final    closing     for radar    tracking       and communication            checks.
                                                                        This plan would           provide      good trajectory          in-
     I was able        to keep the Atlas          in sight for 6        formation     as early as possible           and would give
or    7 minutes         while it traveled         across the At-        me a chance       to adapt       to these new conditions
lantic.        The last, time I reported   seeing it the                if such was necessary.            Other    observations       and
Atlas        was approximately     2 miles behind    and                tasks were to I)e aecomlflished               mainly      on the
 1 mile below the spacecraft.       It could be seen                    second    and third        orbits.      Since    the thruster
easily as it bright object against    the black back-                   problem       made     it necessary         for     me     to control
ground    of space   and later    against   the back-                   manually    during   most of the second and                      third
ground   of earth.                                                      orbits, several   of the planned   observations                    and
                               Orbit                                    experiments     were not accomplished.
    The autopilot          turned    the spacecraft      around                          Attitude         Reference
and put it into          the proper     attitude.     After my
initial contact          with     Bermuda       I received    the          A number    of questions     have been raised over
times   for firing         the retrorockets           and started       the al>ility of a lnall to use the earth's      horizon
the check of the          controls.   This        is a test of the      as a reference     for controlling    the attitude     of
control   systems    aboard     the spacecraft.    I had                the space vehicle.
practiced    it many times on the ground           in the                  Throughout     tiffs flight no trouble    in seeing
Mercury     procedures     trainer   and the test went                  tim horizon       was enc(mntered.                During      tim day
just as it had in the trainer.          I was elated by                 tim earth     is bright     and    the I)ackground           of space

is dark. The horizonis vividly marked. At                             however,      from reference     to the horizon    through
night, beforetile moonis up, the horizon can                          the window        or to the periscope.       Maintaining
still be seen against  tile background      of stars.                 orientation      was no problem,       but I believe that
After   the moon rises (during      this flight   tile                the pilot automatieaUy          relies much more com-
moon was full), the earth is well enough lighted                      pletely     on vision   in space than he does in an
so that tile horizon   cau be clearly    seen.                        airplane,     where gravity    cues are available.       The
   With this horizon     as a l_ference,     the pitch                success     with which      I was able to control         the
and roll attitudes    of the spacecraft     can easily                spacecraft    at all times                              was, to me, one of the
be controlled.     The window     can be positioned                   most significant    features                             of the flight.
where you want it. Yaw, or beading            reference,
however,   is not so good.      I believe    that there
was a learning    period during    the flight regard-                    Weightlessness      was a pleasant    experience.     I
ing my ability     to determine    yaw.     Use of the                reported     I felt fine as soon as the spacecraft
view through    the window      and peri_'ol)e      grad-             separated     from the launch vehicle, and through-
ually improved.                                                       out the flight this feeling      continued      to be the
   To determine     yaw in tile spacecraft,       advan-              same.
tage must be taken of the speed of tile space-                            Approximately       every 30 minutes       throughout
craft   over the earth        which      produces        an ap-       the flight I went through           a series of exercises
parent    drift of tim ground       below the spacecraft.             to determine      whether    weightlessness     was affect-
When the spacecraft         is properly        oriented,     fac-     ing me in any way.           To see if head movement
ing along the plane of the orbit, the ground                  ap-      in a zero g environment           produced     any symp-
pears to move parallel         to the spa(_ecraft         longi-      toms of nausea or vertigo,          I tried first moving,
tudinal     axis.   During    the flight I developed              a    then shaking       my head from          side to side, up
procedure       which   seemed      to help me use this                and down, and tilting       it from shoulder      to shoul-
terrain    drift as a yaw reference.           I would t)itch         der.    In other     words, moving        my head in roll,
the small end of the spacecraft              down to about             pitch,   and yaw.        I began     slowly,   but as the
 -60 ° from the normal          attitude      where a fairly           flight progressed,      I moved my head more rap-
good vertical      view was available.           In this atti-         idly and vigorously       until at the end of the flight
tude. clouds and land moving               out from under             I was moving        as rapidly   as my pressure    suit
me had more apl)arent           motion       than when the            would    allow.    In fiffure 1'2-1 _ the camera    has
spacecraft      was in its normal       orbit attitude       and      caught    me in the middle     of this test, and this
I looked off toward tile horizon.                                     photograph      shows the extent     to which    I was
    At night with the full moon illuminating          the             moving my head.
clouds    below,   I could    still  determine      yaw
through    the window  but not as rapidly      as in the
daytime.      At night  I could also use the drift
of the stars to determine    heading     but this took
longer and was less accurate.
   Throughout     the flight I preferred       the window
to the periscope    as an attitude     reference   system.
It seemed to take longer to adjust yaw by using
the periscope    on the day side.           At night,   the
cloud illumination       by the moon is too dim to
be seen well through      the periscope.
   Three   times during       the flight I turned       the
spacecraft      approximately        180 ° in yaw and faced
forward       in the direction      of flight.   I liked this
attitude--seeing         where     I was going rather than
                                                                      I_GURZ           12-1.--Pilot             looks        to     his        right.         Note     the dis-
where I had         been--much       better.  .ks a result of
                                                                            tance      his     head       can    be     turned            in     the      pressure          suit.
these maneuvers my instrument       reference      sys-
                                                                             All    the       originals         of    these         photographs                 are    in     color
tem gave me an inaccur_tte attitude      indication.                  and       some         detail       is lost       in    the     black             and    white        repro-
It   was     easy   to determine      the   proper     attitude,      duction          of    these     photographs.

    In another    test, using                     only        eye motions,    I      time did I have any difficulty eating. I believe
tracked   a rapidly     moving                     spot       of light gener-        that any type of food can be eaten as long as it
ated by my finger-tip      lights.  I had no problem                                 does not come apart     easily or make crumbs.
watching     the spot and once again no sensations                                   Prior      to the flight,            we joked about                       taking   along
of dizziness    or nausea.     A small eye chart was                                 some      normal    food             such as a ham                       sandwich.       I
included   on the instrument         p_tnel, with letters                            think       this       would         be     practical              and          should         be
of varying    size and with a "spoked          wheel" pat-                           tried.
tern    to check    both     general    vision    and    any                             Sitting    in the spacecraft   under zero g is more
tendency     toward       astigqnatism.       No     change                          pleasant      than under      1 g on the ground,       since
from normal       was apt)arent.                                                     you are not subject         to any pressure    points.       I
   An "oculog)'ric       test"    was made       in which                            felt that I adapted        very rapidly    to weightless-
turning  rates of the spacecraft      were correlated                                ness.      I had no tendency      to overreach    nor did
with sensations     and eye movements.         Results                               I experience      any other sign of lack of coordina-
were normal.      Preflight  experience    in this test                              tion, even on the first movements         after separa-
and a calibration     had been made at the Naval                                     tion.   I found myself    unconsciously       taking  ad-
School  of Aviation    Medicine,    Pensacola, Fla.,                                 vantage   of the weightless    condition,      as when I
with Dr. Ashton     Graybiel,   so that I was thor-                                  would leave a camera or some other object float-
oughly familiar       with my reactions    to these same                             ing in space while I attended       to other matters.
movements       at 1 g.                                                              This was not done as a preplanned              maneuver
   To provide medical data on the cardiovascular                                     but as a spur-of-the-moment          thing      when an-
system,    at intervals,     I did an exercise     which                             other     system            needed        my       attention.                   I thought
consisted     of pulling    on a bungee      cord once a                             later     about        how     I had         done          this    as naturally                    as
second for 30 seconds.         This exercise provided                                if I were            laying     the camera                  on a table             in a 1 g
a known       workload     to compare     with previous                              field.    It          pointedly             illustrates              how    rapidly
similar   tests made on the ground.            The flight                            adaptable             the human              is, even             to something      as
surgeons    have reported      the effect that this had                              foreign         as     weightlessness.                      (See         fig.    12-3.)
on my pulse        and blood pressure.         The effect
                                                                                          We     discovered               from         this        flight            that      some
that it had on me during        the flight was the same
                                                                                     problems           are still    to be solved                 in properly                 deter-
effect      that    is had           on the     ground--it              maxle   me
                                                                                     mining          how        to stow        and      secure         equipment                that
                                                                                     is used in a space vehicle.                          I had brought   along
    Another     experiment     related     to the possible
                                                                                     a number   of instruments,                         such as, cameras,   bin-
medical     effects of weightlessness        was eating     in
                                                                                     oculars,   and             a photometer,  with                     which to make
orbit.     (See fig. 12-2.)     On the relatively      short
                                                                                     observations               from the spacecraft.                       All of these
flight of Friendship        7, eating    was not a neces-
sity, but rather an attempt        to determine     whether                          were      stowed           in a ditty             bag       by     my right               arm.
there would be any problem             in consuming      and                         Each      piece        of equipment                had        a 3-foot             piece       of
digesting      food in a weightless          state.  At no

                                                                                     FIOURE     12-3.--A_fter         his      snack       of    applesauce,            the     pilot

             FIGC_'RE     12-2.--Pilot        opens   visor     to   eat.            leaves    his    expended        tube       hanging          in    air     momentarily.

   684401     0--162------=-@
line attached to it.   By the time I had started                                                    (Sahara      Desert)      part        of Africa          was clear.           As
using items of tim equipment,   ihe_ lines became                                                  I passed over it, the first time I took the picture
tangled._     Although   these lines g'ol ill the way,                                             shown   in figure    12-9.  In this desert region   I
it. was still inq)ortant     to have some way of se-                                               could plainly     see dust storms.   By the time I
curing    the equipment,    as I found out when I at-                                              got to the east coast of Africa  where I might
tempted     to change film.     The snrdl c'misters of                                             have been able to see towns, the land was cov-
film were not tied to the ditty baK by lines.          I                                           ered by clouds.    The Indian   Ocean  was the
left one floating    in midair   while working   with                                              same.
the camera,    and when I reached      for it, I acci-                                                Western       Australia        was clear', but the eastern
dentally   hit it and it floated out of sight behind                                               half  was       overcast.         Most   of the area   across
the instrument     panel                                                                           Mexico and nearly to New Orleans  was covered
                                                                                                   with high cirrus clouds. As I came across the
                             Color        and      Light             "_
                                                                                                   United    States I couhl see New Orleans,     Charles-
   As I looked back at the earth         from sp_e,                                                ton, and Savannah       very clearly.     I could also
colors and light intensities     were much the same                                                see river's and lakes.      I think   the best view I
as I had observed      when flying at high altitude                                                had (if any land area during    the flight was the
in an airplane.     The colors observed    when look-                                              clear desert region around   E1 Paso on the sec-
ing down      at the ground     appeared    similar to                                             ond pass across the United   States.    I could see
those     seen from       50,000 feet.       When    looking                                       the co]ot,-s of the desert and the irrigated     area
toward       the horizon,     however,   the view is com-                                          north of E1 Paso.      As I passed off the east coast
pletely     different,  for then the blackness      of space                                       of the United    States I coul(t see across Florid,_
contrasts       vividly    with the brightness        of the                                       and far back along               the     Gulf     Coast.           (See     figs.
earth.      The horizon     itself is a brilliant, brilliant                                       12-10 and 12-11.)
blue and white.                                                                                       Over the Atlantic               I saw what             I assume was
   It was surprising                      how much of the earth's                                  the Gulf Stream.                 Tim different             colors of the
surface  was covel_d                     by clouds.   The clouds can                               water      are clearly     visible.
be seen very clearly                     on the daylight  side.  The                                  I also observed    what was probably    the wake
different    types     of clouds--vertical          develop-                                       of a ship.     As I was passing  over the recovery
ments, stratus      clouds, and cumulus         clouds--are                                        area at the end of the second orbit,       I looked
readily   distinguished.      There     is little problem                                          down     at the water    and sltw a little  "V."    I
identifying   them or in seeing the weather                                              pat-      ('becked  the map.     I was over recovery    area G
terns.    You can estimate  the relative  heights                                          of      at the time, so I think it was probably    the wake
the cloud layers    from your knowledge        of                                         the      fronl    a recovery     ship.     When    I looked  again
types or from the shadows      the high clouds                                           cast      the little "V" was under a cloud.             The change
on those lower down.       These observations                                             are      in light reflections     caused by the wake of a ship
representative               of information                    which           the     scien-      are sometimes       visible    for long distances    from
tists of the U.S. Weather            Bureau   Meteorologi-                                         an airplane     and will linger      for miles behind     a
cal Satellite    Laboratory       had asked Project     Mer-                                       ship.     This    wake      wits probalily     what    was
cm T to determine.           They are interested      in im-                                       visible.
proving      the optical      equipment     in their   Tiros                                          I believe, however,             that most people                     have an
and Nimbus        satellites    and would     like to know                                         erroneous    conception           that from orbital                    altitude.
if they         could        determine             the        altitude          of     cloud       little detail can tie seen.    In clear desert air,                            it
la.yers with better optical resolution.                                        From my             is common      to see a mountain     range    100 or                          so
flight I would say it is quite possible                                         to deter-          miles .iway very clearly,     and all that vision                              is
mine cloud heights     from this orbital                                        altitude.          through    atmosphere.     From orbital    altitude,                         at-
(See figs. 12-4 to 12-8.)                                                                          lnospheric   light attenuation    is only through     ap-
   Only   a few land areas  were visible                                             during        proxintately     100,o00   feet of atmosp]lere     so it
the flight because of the cloud cover.                                               Clouds        is even more (']ear.     An interesting    experiment
were over         nmch         of the Atlantic,                  but the western                   for future      fligliis   ('an t)e to determine                  visibility
                                                                                                   of objects      of different           sizes,   colors,        arid shapes.
   _A   more      detailed          des(.ription         of    the    visual         ob,_eerva -
tions   taken     from        the    postflight      debriefing            is presented               Obviously,        on    the     night        side      of     the     earth,
 in appendix.                                                                                      much    less was visible.               Tltis   niay      have     been due

                                             =1 ¢1


                                             t.., I=l




          _'t   y"_'l   t

BLACK   AND '/"HITE         P;-;OTOG'RAP.H
   FIOUBE 12-5.--Just      before sunset on the first orbit, the pilot's camera catches the darkening               earth.        The
                             photogral_h shows how the shadows help to indicate cloud heights.

not only to the reduced      light, but also partly     to       from    there    acro._s the    Pacific    until     I was        east
the fact. that I was never         fully clark adapted.          of Hawaii.     There appeared  to be ahnost  solid
Ill the bright    light of the full moon, the clouds             cloud cover all the way.
are visible.    ] could see vertical      develolmmnt   at          Just  off the east coast of Africa   were two
night.     Most of tile cloudy      areas, however,   ap-        large   storm    areas.    Weather        Bureau       scientists
peared to be stratoform.                                         had wondered    whether   lightning    could be seen
   The lights      of the city of Perth,    in Western           on the night side, and it certainly    can.  A large
Australia,      were on and I could see them well.               storm was visible just north       of my track over
The view was similar         to that seen when flying            the Indian Ocean and a smaller one to the south.
at high altitude        at night   over a small town.            Li_zhtning   could be _en flashing    back and forth
South      of Perth    thel_   was a small    group      of      between    the chmds    but most prominent        were
lights, but they were much brighter        in intensity.         lightning    flashes within  thunderheads     illumi-
Inland     there was a series of four or five towns              rotting them like light bulbs.
lying    in   a   line   running    from   east     to   west.      Some of the mo_t st)ectacular    sights during
Knowing    that Perth was on the coast, I was just               the flight were sunsets.  The smlsets always oc-
I)arely able to see the coastline   of Australia.                cur'red   slightly to my left, and I turned     the
Clouds   covered  the area of eastern   Australia                spacecraft     to get a better view.           The sunlight
aromld    Woomera,       and   I saw nothing      but clouds     coming     in the win(h)w was very            brilliant, with


                                                                                                ::    _   L _,,r.::
                                                                                                  '.iic,,_,¢. ,* t ...3
                                                                                                            ,                k.

                                                                                 BLACK     ANt)      WHITE          P_OTOG'RAO_
FmcrRz      l_-_.--Orer            the Atlantle               on the third orbit, the pilot's c_mera          shows     an overcast       region to the north_ves_
                                                       _tnd patterns      of scattered clouds in the foreground.

                                                                                           an intense     clear white    light that reminded   me
                                                                                           of the arc lights        while the spacecraft   was on
                                                                                           the launching       pad.
                                                                                              I watched      the first sunset through    the pho-
                                                                                           tometer    (fig. 12-12) which had a polarizing      fil-
                                                                                           ter on the front so that the intensity                       of the sun
                                                                                           could  be reduced   to a comfortable                          level for
                                                                                           viewing.    Later    I found     that by squinting,     I
                                                                                           could look directly    at the sun with no ill effects,
                                                                                           just as I can from         the surface    of the earth.
                                                                                           This accomplished      little of value but does give
                                                                                           an idea of intensity.
                                                                                               The sun is perfectly      round    as it approaches
Fmu_        12-7.--View             from       Tiros      IV of approximately              the     horizon.        It    retains     most     of     its symmetry
  the    same       area     in     the    Western          Atlantic      as that     in
  figure     12-6.       This      view      shows       the appearance        of the      until     just     the last sliver       is visible.       The   horizon
  cloud     as televised           from       a height       of about      440 miles.      on each          side of the sun is extremely               bright,   and
  Actual       time    of the        photograph           was 1428 G.e.t.         Ph(_
  tograph        is of tile       general       vicinity      of latitude     30 ° N,,     when      the sun has gone              down     to the    level of this
  longitude          60 ° W.            (U.S.      Weather         Bureau      photo-
  graph.     )                                                                             bright      t)and     of the     horizon,        it seems     to spread

                                        g    , , _. r-,.,
                        '.   -     .'   _    ;" .       ,,2

BLACK           ....             " " "-r "-_i-'_";'rC,r-,o^o,'


                     (a)   FI_    orbit.                                                                 (b)      Second      orbit.

FIGURE   12_.--The   Western     Indian       Ocean      was    overcast   on   the   first     and     se_.ond     orbits.     The    relative    heights   of
                                  the     cirrus   and    the   cumulus    clouds     can     clearly    be seen.
128                                                                                                                           C i.":!_.!:_:AL     i",_,_ _
                                                                                                         _LACK             AND        WHITE        P_--.'OTOGRAPN
     FIGUZE12-9.--View       looking back toward the African coast on the first orbit. The photograph            from the pilot's
                                   camera shows the desert with blowing sand in the foreground.

     out to each side of the point where it is setting.               band than the camera       captures.   One point of
     With the camera    I caught  the flattening of tlle              interest   was the length     of time during   which
     sun just before    it set (fig. 1'2-13(b)).    This is           the orbital   twilight  persisted.   Light   was vis-
     a phenomenon      of some interest      to the astron-           ible along the horizon    for 4 to 5 minutes   after
     olners.                                                          the sunset, a long time when you consider        that
        As the sun moves toward the horizon,        a black           sunset occurred   18 times faster   than normal.
     shadow   of darkness     moves across the earth un-                 The period immediately          following     sunset was
     til the whole surface,      except     for the bright    band    of special interest    to the astronomers.          Because
     at the horizon,    is dark.     This      band is extremely      of atmospheric      light   scattering,      it is not pos-
     bright   just as the sun sets,         but as time passes        sible to study the region close to the sun except
     the bottom     layer becomes       a    bright  orange     and   at the time of a solar eclipse.         It had been hoped
     fades into reds, then on into            the darker    colors,   that from above the atmosphere               the area close
                                                                      to the sun could I)e observed.              However,     this
     and finally    off into the blues and blacks.       One
     tiring that    surprised    me was the distance       the        would require a period of dark adaptation  prior
     light extends     on the horizon    on each side of the          to sunset.   An eye patch   had been developed
     point    of the sunset.      The     series of pictures          for this purpose,       which was to be held in place
     shown in figures 12-13 and 1_-14 illustrates          the        by special     tape.      This patch   was expected    to
     sequence    of this orbital   twilight.     I think that         permit   one eye to 1)e night         adapted  prior   to
     the eye can _e a little more of the sunset color                 sunset.    I'nfol'tunately,     the tape proved unsat-


FILACK                ....
         ANL)"$,:',_'_*,:    i _ _,. ,.._,_,.._F_-14
                             ' '_'-"r'L_"


FIouaE   12-10.--At   the   beginning           of    the      third      orbit,   the      pilot   catches       a panoramic       view   of   the   Florida   coast,   from
                               the      cloud        covered           Georgia     border       to just       above   Cape   Canaveral.

130                                                                                                                                _,_.ij!t :Ai. i, .:_..
                                                                                                                  BLACK         ',Nn WHITE                PI4OTO(3'RAP.H
FIOURE      12-11.--View            of the       Florida     area     from     Tiros
   IV taken        at 1610       G.e.t.    on February          20, 1962.        This
   photograph         shows       the band        of clouds      (across      South-          FIounE   12-12.--During        sun,t,      the pilot   used   the
   ern    Florida)         which        had     moved       away      from      Cape                         photometer     to view     the sun.
   Canaveral         earlier       that      morning.        The     clouds       just
   north    of Florida        are apparently             the ones     plainly      vis-
   ible in figure         12-10.         (U.S.     Weather       Bureau       photo-      the brightness       of a first magnitude         star and
   graph    ; major      land masses           are outlined       in white      ink.)     appeared      to vary in size from a pinhead          up to
                                                                                          possibly    _ inch.     They were about 8 to 10 feet
isfactory    and I could    not use                           the eyepatch.               apart    and evenly distributed     through      the space
Observations    of the sun's corona                             and zodiacal
                                                                                          around     the spacecraft.      Occasionally,       one or
light     must.      await       future        flights      when        the    pilot      two of them would move slowly up around                 the
may have an opportunity                         to get more           fully    dark       spacecraft     and across the window,     drifting    very,
adapted prior to sunset.
                                                                                          very slowly, and             would    then      gradually    move
    Another      experiment       suggested      by our advi-                             off, back in the            direction     I     was looking.      I
sors in astronomy        was to obtain ultraviolet          spec-                         observed     these luminous       objects    for approxi-
trographs      of the stars in the belt and sword of                                      mately    4 minutes     each time the sun came up.
Orion.      The ozone layer of the earth's                atmos-                             During     the third   sunrise    I turned    the space-
phere will not pass ultraviolet            light below 3,000                              craft   around     and faced      forward      to see if I
angstroms.         The spacecraft        window       will pass                           could determine       where the particles      were com-
light down to %000 angstroms.                   It is possible,                           ing from.      Facing     forwards    I could     see only
therefore,     to get pictures       of the stars from the                                about    10 percent    as many      particles    as I had
Mercury      spacecraft     which cannot be duplicated                                    when     my back w_s to the sun.              Still,  they
by the largest       telescopes     on the ground.           Sev-                         seemed     to be coming      towards      me from some
eral ultraviolet      spectrographs        were taken of the                              distance    so that they appeared         not to be com-
stars   in the belt        of Orion.        They     are being
                                                                                          ing from the spacecraft.       Just what these par-
studied    at the present       time to see whether          use-
                                                                                          ticles are is still subject   to debate  and awaits
ful information        was obtained.                                                      further   clarification.  Dr. John O'Keefe    at the
   The biggest     surprise   of the flight   occurred
                                                                                          NASA     Goddard      Space Flight    Center   is mak-
at dawn.     Coming     out of the night on the first
                                                                                          ing a study     in an attempt     to determine    what
orbit, at the first glint of sunlight    on the space-
                                                                                          these particles    might   be.   (See appendix     D.)
craft, I was looking    inside the spacecraft        check-
ing instruments     for perhaps       15 to 90 seconds.                                                Other      Planned      Observations
When I glanced      back through         the window      my
initial reaction  was that the spacecraft         had tum-                                   .ks mentioned        earlier,  a number     of other ob-
bled    and that   I could    see nothing        but stars                                servations   and       measurements     during    orbit had
through    the window.      I realized,     however_ that                                 to be canceled         because    of the control      system
I was still in the normal       attitude.      The space-                                 l)roblems.     Equipment         carried   was not highly
craft was surrounded      by luminous   particles.                                        sophisticated       scientific      equipment.    We    be-
   These particles   were a light yellowish        green                                  lieved,    however,    that    it would    show the feasi-
color.  It was as if the spacecraft    were moving                                        I)ility   of making   more        coml)rehensive           measure-
through    a field of fireflies.  They   were about                                       ments     on later missions.




FIOURE 12-13.--The      third orbital sunset as shown by a series of three photographs.       The camera   catches   the
                     flattening of the solar disk just before the sun disappears below the horizon.
   Some of these areas of investigation that we               I could hear    each rocket      rite and could   feel
planned but did _wt h'_ve an .opportunity    to            the surge as the rockets slowed the spacecraft.
check are as follows:                                      Coming out of zero-g condition, the retrorocket
   (a)   Weather Bureau observations:                       firing produced the sensation that I was accel-
           (1) Pictures of weather    areas and            era.ring back toward Hawaii (tiff. 12-15).        This
                 cloud  formations    to match             _nsation,     of course, was an illusion.
                    against map forecasts    and Tiros          Following retrofire the decision was made to
                   pictures                                have me reenter with the retro package still on
           (2)   Filter mosaic pictures      of major      because of the uncertainty          as to whether the
                    weather centers                        landing bag had been extended.           This decision
           (3) Observation   of green         air glow     required     me to perform       manually    a number
                 from air and weather        centers in     of the operations which are normally autonmti-
                  5,577-angstrom        band with air      tally programed         during   the reentry.    These
                  glow filter                              maneuvers       I accomplished.        I brought     the
           (4) Albedo      intensities--measure      re-   spacecraft, to the proper attitude         for reentry
                  flected light intensities on both        under manual control.          The periscope was re-
                  day and night side                       tracted by pumping the manual retraction lever.
   (b)   Astronomical    observations:                         AS deceleration began to increase I could hear
           (1) Light polarization         from aretr of    a hissing noise that sounded like small particles
                  sun                                      brushing against the spacecraft.
           (2) Comets close to sun                             Due to ionization around the spacecraft, com-
           (3) Zodiacal light                              munications      were lost.    This had occurred on
           (4) Sunlight intensity                          earlier missions and was experienced           now on
           (5) Lunar clouds                                the predicted       schedule.    As the heat pulse
           (6) Gegenschein                                 started there was a noise and a bump on the
           (7) Starlight   intensity measurements          spacecraft.      I saw one of the straps that holds
   (c) Test for otolith balance disturbance    and         the retrorocket      package swing in front of the
autokynesis    phenomena                                   window.
   (d) Vision tests:                                           The heat pulse increased until I could see a
           (1) Night vision adaptation                     glowing orange       color through       the window.
           (2) Phorometer     eye measurements             Flaming     pieces were breaking       off and flying
   (e) Drinking                                            past the spacecraft    window.       (See fig. 12-16.)
                                                           At the time, these observations         were of some
                        Reentry                            concern to me because I was not sure what they
                                                           were. I had assumed that the retropaek             had
    After having turned around on the last orbit
                                                           been jettisoned when I saw the strap in front of
to see the particles, I maneuvered into the cor-
                                                           the window.       I thought these flaming pieces
rect attitude    for firing the retrorockets      and
                                                           might be parts of the heat shield breaking off.
stowed the equipment       in the ditty bag.
                                                           We know now, of course, that the pieces were
    This last dawn found my attitude indicators
                                                           from the retropack.
still slightly in error,    tIowever, before it was
time to fire the retrorockets   the horizon-scanner          There    was no doubt when the heat pulse oc-
                                                           curred during reentry but it takes time for the
slaving mechanism had brought tim gyros back
                                                           heat to soak into the spacecraft         and heat the
to orbit attitude.    I crosschecked repeatedly be-
                                                           air. I did not feel particularly         hot until we
tween the instruments,         periscope presentation,
                                                           were getting down to about 75,000 to 80,000
and the attitude through the window.
                                                           feet. From there on down I was uncomfortably
    Although there were variations in the instru-
ment presentations        during the flight, there was     warm, and by the time the main parachute was
never any difficulty in determining         my true at-    out I was perspiring    profusely.
titude by reference to the window or periscope.               The reentry deceleration       of 7.7g was as ex-
I received a countdown from the _'round and                pected and was similar to that experienced           in
the retrorockets     were fired on schedule just off       centrifuge  runs.     There had      I>een some ques-
the California     coast.                                  tion as to whether    our ability    to tolerate acce]-




IaI0VRE     12-14.--The              first    orbital          sunset        is   recorded        in   a   series   of     four       photographs.            Patches         of   high       clouds       glow

      orallge     Its     tire   suit's      light      is    diffra_.te4           by   the   _tutosl_here.             The      bright      hai_d   _,f   Slmce       twilight          grows        dimmer

      and shrinks            in length         with          passing        time.


                                                                                                                                     EtLACK AND                     WHITE                 PHOTOGRAPH
FIGURE    12-15.--Pilot      concentrates        on instruments       while    FIGURE   12-16.--Pilot         looks   out       of   window      at   fireball
             controlling     attitude     during    retrofire.                              during       maximlma     reentry        heating.

eration     might be worse because of the 41_ hours                            Noa was alongside        the spacecraft,   there   was
of weightlessness,         but I could note no difference                      little delay in starting    the hoisting  operation.
between my feeling of .deceleration             on this flight                 The spacecraft   was pulled     part way out of the
and my training           se_ions     in the centrifuge.                       water to let the water drain       from the landing
   After i)eak de(.eleration,          the amplitude      of the               bag.
space('raft     o_illations       began to build.        I kel)t                   During    the spacecraft    pickup,    I received    one
them under control            on the manual       and fly-by-                  good bump.         It was probably        the most solid
wire systems        until    I ran out of manual            fuel.              jolt of the whole trip as the spacecraft             swung
After" that point,   I was mlknowingly    left with                            against    the side of the ship.          Shortly     after-
only the fly-by-wire   system and tile oscillations                            wards the spacecraft         was on the deck.
increased;     so I switched      to auxiliary       damping,                      I had initially     planned     egress out through
which controlled       tile sl)acecraft      until the auto-                   the top, but by this time I had been perspiring
marie fuel was also expended.              I was reaching                      heavily    for nearly     45 minutes.        I decided      to
for the switch      to deploy the drogue            l)arachute                 come out the side hatch instead.
early    in order    to reduce     these reentry        oscilla-
                                                                                                        General       Remarks
tions, when it was deployed          automatic'ally.         The
drogue      parachute      stabilized      tile    spacecraft                     Many things      were learned     from the flight of
rapidly.                                                                       Friendship    7.    Concerning      spacecraft      systems
   At 10,800 feet           the main     parachute     was de-                 alon% you have heard        many reports        today that
l)loyed.  I could           see it stream     out hehind   me,                 have verified    previous    design    concepts     or have
fill I)artially, and          then     as the reefing     line         cut-    shown weak spots that need remedial               action.
ters were actuated               it   filled COmllletely.              The        Now_ what can be said of man in the system ?
opening     of the parachute        caused    a jolt, but
perhaps   less than I had expected.                                                                          Reliability
   The landing     deceleration     wqs sharl)er    than ]                         Of major       significance     is the probability      that
had expected.       Prior     to impact    I had discon-                       much      more dependence            can be placed       on the
nected  all the extra      le,lds to my suit, and was                          man as a reliably         operating     portion   of the man-
ready     for rapid     egress, but there was no need                          spacecraft      combination.        In many areas his safe
for" this.     I had a message          that tile <lestrt)yer                  return    can be made dependent               on his own in-
3%. would        pick me u 1) within          20 minutes.     I                telligent     actions.      Although      a design     philoso-
lay quietly      in tlle sI)a<'ecraft     trying  to kee I) as                 phy     could     not be followed          up to this time,
cool as p<)._sit)le. The temperature               insi(le the                 Project     Mercury       never considered      the astronaut
sl)acecraft    did not seem to diminish.          This, com-                   as merely a passive passenger.
bined with the high humidity                of the air being                      These areas nmst be a'_o_sed    carefully, for
drawn      into the spacecraft        kept me uncomfort-                       man    is not infallible, as we ate all acutely
ably     warm      and     l)ersl)iring       heavily.        ()nee     tile   aware.     As      an      inflight    example,            some        of you

mayhavenoticed slight discrepancy   between                     and capabilities      are little changed      in space.  At
launchphotographsf thepilot andsimilarre-                       least for the 4.5-hour        duration    of this mission,
entry views. Thefaceplateontile hehnet as                       weightlessness      was no problem.
open during the reentry phase,tlad cabin                           Man's     adaptability       is most evident       in his
         s      to
pressuretarted drop,I couldhave   closedthe                     powers     of observation.          He can accomplish
faceplatein sufficient.imeto preventdecom-                      re'my    more and varied          experiments      per mis-
                                                                sion than can be obtained            from an unmanned
          but            a
pression, neverthelessface-plate-open    re-
entry wasnotplanned.                                            vehicle.    When the unexpected       arises, as hap-
  On the ground,some    things wouldalsobe                      pened    with the luminous    particles      and layer
done                            I
     differently, Asanexample, feelit more                      observations  on this flight, he can make observa-
advisable the event of suspected malfmw-
           in                                                   tions that   will permit     more rapid     evaluation
lions,   such as the heat-shield-retropaek             diffi-   of these phenomemL       on future flights.     Indeed,
culties,  that t_xluire extensive     discu._ion     among      on an unmanned      flight there likely would have
gr(mnd     pel_onnel   to keep the pilot updated          on    been no such observations.
each bit of information      rather    than waiting      for
a final      elear(!ut  recomlnendation          from    the                            Future      Plans
ground.    This keeps the pilot      fully informed               Most     important,      however,        the    future   will     not
if there would happen    to be any communication
                                                                always find us as power limited                   as we are now.
difficulty and it became     necessary     for.him    to
                                                                We will progress      to the point               where   missions
make all decisions   from onboard        information.
                                                                will not. be. totally  preplannext.                There will be
   Many     things   would  be done    differently
                                                                choices of action in space, and man's intelligence
if this flight could be flown over again, but we
                                                                and     decision-making       capability      will     be
learn from our mistakes.      I never flew a test
flight on an airplane       that I didn't     return wish-
                                                                    Our recent space efforts can be likened        to the
ing I had done some things          differently.
                                                                first flights    at Kitty ttawk.       The)" were first
    Even where automatic        systems are still neces-
                                                                munanned      but   were    followed                 by  manned
sary,   mission   reliability     is tremendously       in-
                                                                flights, completely    preplannM                  asad of a few
creased   by having     the man as a backup.           The
                                                                seconds   duration.           Their   experiments   were,
flight of Friendship     7 is a good example.           This
                                                                again, power limited,          but they soon progres_d
mission   would    almost certainly   not have         com-
                                                                I)eyond that point.
pleted its three orbits, and might not have            come
                                                                   Space exploration             is now     at the     same       stage
back at all, if a man had not been aboard.
                                                                of deveh)pment.
                                                                   From all of the papers    in this volume,   I am
                                                                sure you will agree with me that some big steps
   The    flight   of    the   Friendslup      7   Mercury      have been taken loward    accomplishing    the mis-
spacecraft    has proved that man can adapt very                sion   objectives       expressed     at    the     beginning        of
rapidly    to this new environment.    His senses               this   l)aper.

                                                      13.            SUMMARY                 OF    RESULTS

BY GEORGE M. Low,                        Director o[ Space Cra]t and Flight     Missions,   O_ce                            o/   Manned     Space      Flight,
                                                 National Aeronautics and Space Administration

  The       fa_'t that         J(}lm Glenn's              flight        was 'm un-           signed  for other lmrl)oses,     to lnake lhem               suit-
qualified   slwcess is well (locnmented      in the pre-                                     able for manned   fli_zht.   The develol)ment               of an
ceding    papers.    This   fli_zht marked      a major                                      ab(>rt sensing' system,    together    with the             most
milestone    in the United    St:lies program     for the                                    stringent  quality control, has I>ermitted  the use
manned     explorati(m      of sl)ace.      It would  seem                                   of the Atlas missile   in a 1)rogram   for which it
io be alil)rol)riate,    at this lime, to sum u l) what                                      was not designed     or developed.
has been learned       during    tiffs first l>hase and to                                      A knowledge    (if how 1() implement                an exten-
interpret         the      results         in terms             of     future      mis-      sive network    of tracking      stations,            a network
sions.                                                                                       which is unique in that it makes use of real-time
  In the fall of                   1958      the      stated   objective    of               dat_  transmission   and   real-time  computing,
Project  Mercury                    was      to:       "Determine       man's                anti thereby     permits        real-time     flight     control,
capabilities   in a space environment."       This ol/-                                      has been gained.
                                                                                                (h'(mnd   rules have         been    established       for   re-
jective    has been achieved   for the missions    ac-
complislmd     to date.   Man's re'wtions   to the ac-                                       covery     from space.      It has been learned    how
celerat ions of laun('l_ and to the decelerations   of                                       shil>s and aircraft,      with information   provided
reentry       have been learned.                          It has 1)een deter-                by the tracking      network,  can locate and retrieve
mined        that a trained  pilot                       can pel'fornl  tasks                a sl)a(!ecraft  after it has landed.
under a relatively   high g-stress   as well as under                                            Some of the items that        were developed     for
zero-g,  can monitor    all his systems,    can mann-                                        Project     Mercury    will find use in other    fields.
ally control   the flight sequence,      and can ade-                                        For     examl)le,   tim new liffhtweight      survival
quately  control   the attitude     of his crqft.     The                                    equipment       mi_zht well lie used by Air-Rescue
period  of weighllessness       has been extended       by                                   _rvicesthroughout         the world.  The biomedical
more than     two orders     of magnitude--from           1                                  instrmnentqiion       for measuring  respiration  rate,
minute   to nearly     300 minutes.        It has been                                       temperature,       activity    of the heart,     and blood
learned   that there are no ([eleterious          psycho-                                    pressure     and for transmitting         the_    quantities
logical      or        physiological            effects          resulting         from      over lon_z distances        may also find uses in fields
                                                                                             other than the exploration         of space.
this     prolonged             exp(lsure        to weightlessness,                  even
                                                                                                Extensive     training     and simulation       has been
though         attemlltS             were       made            to     induce       such
                                                                                             found     to be an absolute           requirement.         The
                                                                                              training    of the pilots has, of course,    received    a
    In      Project            Mercury,            far      more          has       been
                                                                                              great    deal of attention.    Equally    important      is
 learned       than        was       ant icil)ated--far                  more       than      the extensive     si|mllation  of flights   cqrried   (,at
 merely      the        determination                of man's           capabilities         by all persons         involved      in an      actual  opera-
 in spa('e.            A knowledge               of how              to design_,       de-   lion.  All the       flight    controllers       and the net-
 velop and nmnuf'lcture       a craft                            sllecifically        en-     w()rk, computer,        and conmmnications              experts
 gineered for man's     flight into                              space has          been      have performed         literally      hundreds     of practice
 gained.          It     has      been      learned         how,        through        an     missions   wherein       every conceivable          emergency
 intensive         ground          and      flight       lest        program,       su('h     was simulated.         Through         these exercises,    they
 a spacecraft             can      lie developed                to carry        out    its    have learne(l    t(i   work together          as a well-tim('-
 assigned              mission.          _Vays           lmve          been        deter-     tioninlz team,     a   team      that     supports    the pilot
 mined       to modify               existing         branch           vehicles,       de-    throughout     his mission.

  Mostimportantof all, it hasbeenlearned                  is still in its earliest      development     stages. The
that a well-trainedi)ilot, like Shepard, ris-             flights   of Shepard,        Grissom,     and Glenn   were
som,or Glennor like the otherastronauts, can              pioneering     ventures      and, as such, were not un-
performa missionill Sllaee as well as he                  dertaken    without     risk.
can perforu_a missionin tile earth's atmos-                  In a('('ept ing the challenge    of future flights, in
phere.                                                    Projects    Mercury,    Gemini,   and Apollo, it should
   The knowledge     derived    in the last g years is    not be forgotten      that the risk in these missions
tremendous.     Yet, in recognizing       this fact, it   will be at least as great        as it has been in the
must also be recognized     that manned    space flight   past.

                                                                                              APPENDIX                            A

     MERCURY                                            NETWORK                              PERFORMANCE                                      SUMMARY                                        FOR            MA-6

              By THE MANNED SPACE FLIGHT SUPPORT                                                            DIVISION,         NASA              Goddard                  Space Flight                 Center

                                                  Summary                                                         Bermuda               FPS-16
                                                                                                                            Data        points        ..............................                                                50
   The l)erfomnance        of the Mercul T Network                                                                          Range,          yd     ...............................                                               8. 6

was considered      highly    successful     for the Mer-                                                                   Azimuth,              rail     ...........................                                         0. 17
                                                                                                                            Elevation,             mil ............................                                            0. 49
cury/Atlas-6     mission.      At tile time of launch,
                                                                                                                  Muchea              Vcrlort
 14:47:39Z   on February      20, 19(;2, all systems re-
                                                                                                                            Data        points   ..............................                                                   93
quired    to SUl)port the flight were ol)erational.
                                                                                                                            Range,         yd ..............................                                                   17. 6
This     was l)henonmnal        considering      the wlst
                                                                                                                            Azimuth,             rail .............................                                            0. 97
amount of equilmlent        committed      to support the                                                                   Elevation,              rail ...........................                                           0. 81
                                                                                                                  California               Verlort
                                                        Radar                                                               Data        points        ..............................                                                49
                                                                                                                            Range,           yd ...............................                                                  7. 0
  The         Mercury                        Network                       includes   both    C-band
                                                                                                                            Azimuth,             mil .............................                                              0.60
and S-hand      radars located  around    tile Mercury                                                                      Elevation,             rail ............................                                           O. 90
ground    track in such a manner     that redundancy
is afforded    in case of a spacecraft     beacon fail-
                                                                                                                        A      summary                     of        the             radar        data         received             at
ure.   The radars     have a range    capability       of
approximately     500 miles for the ('-band      radai_                                                           Goddard                   during                 this              mission           (including                all
and 1,000 miles for the S-band       radai,'s.    During                                                          t)oints)             is shown                  in table                 A-I      (see     ref.          1, table
this mission,  all radar    sites tracked      the space-                                                         12,        p.      68)         and           the         radar             coverage             times         are
craft with C-band     and/or     S-b_md radal_      when                                                          shown              graphically                       in figures                 A-1       to A-6.
it was within      range.    ]_)at_t were supplied,       in
real time, to tile du'd       Goddard    conq)uters       at                                                                                                      Computing
the rate of one data i)oint per 6-second            inter-
                                                                                                                      Throughout                          the mission    the automatic       con>
val.    An average     of about 50 radar data points
                                                                                                                  l)uting   system                        at Gc<ldard    effectively     used the
was received     from each site with as many as 93
                                                                                                                  network      data                      to suI)ply   real-time      digital  dis-
points   from several.       A nrljority   of tile sites
tracked    the sl)acecr,tft  from one horizon       to the                                                        play and plot t)oard information     to the Mercury
other.    The tracking      was of such quality       th'tt                                                       Control  Center    at Cape     Canaveral.    During
tile Goddard  computers                                                  were   SUl)plied  with                   launch              the        high-speed                          data       from        the       Cape          to
more than enough    data                                               to update    the orhital                   Goddard                    were               uninterrupted                            and         of      good
paranmters      for each orbit.     The quality       of the                                                      quality,              and          the          flight                 parameters               were         such
network     data    is indicated     by the following                                                             that         the         computer                      recolmnended                       a GO.              The
typical    wdues    of standard     error    (eliminating                                                         Goddard                    computers                          quickly              established                the
all data    i)oints   for 1)ointing    angles     below 3 °                                                       orbit            from           early              network                  data        and        supplied
elevation)    :
                                                                                                                  real-tiIne acquisition data to all sites. The pre-
Woomera              FP8-16                                                                                       cision of the data was indicated   by the fact that
    Data             points             ............................                                   _5         the        tinle         of      retrofire,                    as       reconlmended                    by    the
    Range,                yd     ..............................                                    6. 9
    Azimuth,                   rail ............................                                  0. 08           computers,                     was             adjusted                    hy      only         '2 seconds
     Elevation,                   mil        ...........................                          0. 2,5          during              the entire                  mission.                   During            the        reentry

          _,_4,t01    0    -62      -   10
                                                       TABLE A-I.--Orbital                                    Data Analysis,                       Radar              Tracking

                                                                                            Total                                                                                   Standard         Deviation
                                                                                          possible              Valid                 Nonvalid
            Station                                    Radar                                valid             observa-                observtt-

                                                                                          observa-               I ions                   tions                   Range,           yd       Azimuth,                  Elevation,
                                                                                            tions                                                                                              mils                       mils

   First.     pass:
             BI)A                  _         FPS        t6       ....                                71                   52                          3                     3,1. 5                  0. 34                    0. 61
             BI)A                                   V,,rh)rt         _                               71                   47                          8                     26. 8                   1. 7                     1. 6
             ('YI_                                  Verlorl                                          68                   63                          9                     73. 3                   1.4                      2.0
             XI U (                                 Vcrlor        t __                               82                   76                          6                     23. 4                   1. 94                    1. 47
             W()M                            FPS            16                                       4O                   3(,)                         1                      6. 9                   . 077                     . 25
             (;YM___                              Verlort         __                                 65                   51                         14                     3O. 3                   1. 02                    1. 82
             Wtt       S                     Ft'S           16                                       :t4                  28                          6                       5. 9                   . 22                    1. 20
             TEX                                    Verh)rt_             _                           64                   46                         18                     71. 0                   '2. 69                   1. 60
              EGL                            I;PS           16                                       40                   38                           1                      8. 58                  .2_0                      .477
              E(',L                                 MI)Q           31                                65                   18                        47                      38. 7                   2. 85                    2. 35

   Second         [)ass:
              ('NV                           FPS            16                                       64                   43                        21                      39. 3                    .288                      .871
              BI)A                           FPS            16                                       66                   51                        15                      1t. 5                    .380                      . 656
              BI)A                                  Verlort              _                                                       I)ATA             NOT            AVAII,ABLt"
              ( 'YI_                                Verlort              _                           54                   48                          6                 27. 1                       1.71                      1. 54
              MU('__                                Vcrlort__                                        8O                   60                         2()                    :it,). 1                1.43                      1. 32
              WtlM                           FPS            16                                       33                   28                          5                       2. 28                   . (181                   .13
              tlAW__                         FPS            16_                                      15                   15                          0                       4. !12                  .313                     . 251
              tIAW                              Verlort   __                                         56                   45                         11                     80. 1                   1. 89                     1. 35
              ('AL.                           FPS    16__                                            38                   28                         10                       8. 88                   • 544                    • 208
                                                    Veflort        ....                              47                   27                         20                     20.     1                 • 705                    .8O0
              WtIS             _             FPS-16                 _                                41                   31                         10                     17.2                      • 179                    . 669
              TE X                                  Verlort_             _                           60                   58                          2                     41.5                    1.61                      1.41
              EGI      ......                F PS           16 _                                     40                   32                          8                       6. 85                   .209                     • 286
                                                    MPQ            31                                5O                   32                         18                 103.       8                3. 82                    3. 74

   Third        pass:
              CNV              _   _ _       FPS            16__                                     64                   26                         38                     57. 3                     • 318                    • 936
              BI)A         _           _      FPS       -16                                          65                   56                          9                     3O. 6                     • 157                    • 561
                                                    Verlort_             _                                                        I)ATA          NOT               AVAILABLE
              CYI_                                  Verlort_             _                                                                  I)UT    ()F             RANGE
              MUC__                                 Verlort_              _                          70                   69                           1      [        :11,6            [             • 8O3                   1. 24
              W()M             _       _      FPS    16=                          .                                                         ()UT           ()F      RAN(;E
              It AW___                        FPS-16                                                 38                   37                           1                      8. I)5                  • 230                    .   ,')Ot

                                                    Vcrlort             __                           64                   52                         12                     38. 6                   2. 07                     1.6O

 BDA                       f---
 WOM                                                                                                                                        F--1
 CAt.                                        _RADAR                          COVERAGE                                                                                                                            v_
 WHS                                                            COVERAGE
                                             F---1HORIZON-rO-HORIZON                                                                                                                                                  r--]
 EGL                                              I ,I   I   d  I  ,I    ,_                                                                                                                     i

  GM'r 14:47:3_}                            57                 15:07                       17               27                  37                   47                       57               1607                    17                  27
  GET   O:OO                               0:10                 0:20                      0:30             0:40                0:50                  I:00                     1:10              1:20                  1::30                1:40

                                                                             FzGtra_.      A-1.      C-band       radar          coverage,           first         orbit.

 XN-I                                                                                                                                                                                                    r--'l
 GBI                                                                                                                                                                                                     I--]
                                          RADAR        COVERAGE
 WHS                                                  COVER,'_
                                  ---1HOR,ZON-'ro-HOR,ZON                                                                                                                              [--]
 EGL                                  I  ,I  1 J      l   ,]
                               16:_'    47       $7     ,7_                                                17                  27                      37                     47                               57                           1_07
 GET            1:40             1:50          2:00              2:10                  2:20               2:30                2:40                     2:50                  3:00                             3:10                          3:_0

                                                       FIGVRE     A-2.        C-band          radar       coverage,           second          orbit.


  GBI                                                                                                                                                                                      r--       7
  SAN-SAL                                                                                                                                                                                    r--          1


  HAW                                                                                                                                  r-'-
  CAt                                 m   RADAR         COVERAGE                                                                                                   r_
                                                                                                                                                                            1 I
  WHS                                     HORIZON-TO-HORIZON                   COVERAGE
  EGL                                     I         _1      I          ,1       I          I1                                                                                      ,l
          GMT                    18:17           27               37                    47                   57                19_7                         17                    27                            57                           47
          GET    :_20            3:30           3:40             3:50                  4:OO                4:10                4:20                    4:30                  4:40                             4:50

                                                        FIGURE        A-3.     C-band           radar      coverage,          third       orbit.

 CNV      MOO ]I
 BDA-VER                   F
 C_1 -VE R
                                                                                                                         I                                                                                                              f---


                                                                                                                r--                                                                                                 i
 CAL-VER                                                                                                                                                                                                 r--
 GYM -VER                                      RADAR       COVERAGE

 TEX-VER                                   j   HORIZON-TO-HORIZON                   COVERAGE                                                                                                             '                 i
 EGL-MPQ-_M                        IJ               1                 I         E I                   1                                                                                                                 r---         ---7
  GMT     14:47_39                57            1507               W                    27                 :57                 47                       57                   16:07                              17                           27
   GET          000              0:10          0:20              0:50                  0:40                0:50                 I:00                        I:10                  1:20                         1:30                          1:40

                                                        FIOURE        A--4.    S-band            radar       coverage,         first      orbit.

CNV     MOO 11"

BDA-VER            ----7

CYI-VER                        r--1
MUC-VER                                                                                         [--
.IAW-VER                                                                                                                                               r-

                                                                                                                                                                            r--                  I
GYM--VER            ....              m   RADAR        COVERAGE
TEX-VER                               _   HORIZON-TO-HORIZON                  COVERAGE

                                          ] ,l ] ,I I ,1
                                                                                                           17                 27                   37                        47                           57                           18-u7
   GMT                         1_37            47                57                 17:07
                                                                                                          2:30               2:40                  2:50                     3:00                         3:10                          :5:20
   GET          1:40             1:50          2:00              230                2:20

                                                       FIOUBE    A-5.         S-band          radar       coverage,          second           orbit.


 CYI-VER                                                                                                                                  I



                                       RADAR         COVERAGE         __                            .,         ;        .                _       _,


 EGL-MPQ-31                    r_l     lHORIZON-TO-
                                             ,I            1 HORIZON
                                                                ,k          COVERAGE
                                                                            I    ,I                            i
                                                                                                               'l                        ,t            r--1 n _1

      GMT               18t7                  27              37                    47              57              19:07               17                27               37             47
      GET     3,:20     3:30                  3:40            3:50                  4:00            4:10             4:20              4:30"             4:40              4:50

                                                     I_OURE    A-6.        S-band          radar   coverage,        third     orbit.

phase       of tile mission,    the network     data   1)er -                                      mission.            After           a number             of     sites        confirmed
mitred       a comt)utation  of predicted  landing   point                                         that this event was indicated,   the astronaut     was
which       varied by only 2 miles.                                                                informed   and given a course of action.
                                                                                                      A summary    of telemetry   subsystem    perform-
                      Acquisition                    Aid                                           ante is shown in tables A-II     to A-VII     and the
   The automatic    acquisition   aid sul)svstems     1)er-                                        telemetry          coverage times                   are shown           graphically
formed as expected     with no major t)roblems en-                                                 in figures         A 7 to A 9.
countered.    As usual, multipath      was a problem
                                                                                                                            Voice       Communication
at low elevation    angles and, therefore,       manual
elevation   control     was     used.   Four      sites--
                                                                                                      Voice communication         between the ground           and
Canary       Island,      Muchea,       California,        and                                     the spacecraft      was considered         excellent.       The
Texas--used       real-time    conqmted       pointing    data                                     quality   of the air-ground        voice communication
for direct radar acquisition,         indel)endent      of the                                     monitored    on the Goddard         conference        loop was
automatic     acquisition    systems.      This was excel-                                         very good and provided          the flight controllers        at
lent verification      of the accuracy       of acquisition                                        Mercury     Control     Center    with adequate           moni-
data   furnished       to the network        radars    by the                                      toring capability      throughout      the mission.
Goddard     computers.
                                                                                                       The coverage     times of tIF         and UHF          com-
                           Command                                                                 munications     are shown       graphically        in figures
                                                                                                   A-10 to A-12.
   The command           subsystems   operated                        in a saris-
factory  manner         for tile miasion    with                      a total of                                                              Timing
eleven functions        being successfully                      t]'ansmitted
to the spacecraft       from various sites.                                                              Tile tinting          system           performed   very well with
                                                                                                   the     exception           of the          serial decimal   GMT time
                           Telemetry                                                               used on the stril)-chart                             recorders           at Hawaii
                                                                                                   and Kano.   The real-time                               records          from these
   The telemetry     subsystem    recet)tion     and 1)er -
                                                                                                   sites are usable                in spite           of the timing               malfunc-
formance    was ontstandingly     good.      All stations
acquired   and lost signals at or near the horizon.
                                                                                                                              Data        Transmission
No major operator      error or equipment        malfunc-
tion was reported     that influenced      mission    mon-
                                                                                                       No problems     were encountered     with the data
itoring   and control.                 The         maximum   range  of
                                                                                                   transmission     system;   all high-speed     "rod low-
telemetry    recet)tion              varied         from 500 to 1,100
                                                                                                   sl)eed data    lines were ol)erational      during   the
                                                                                                   ent ire mission.
    The malfunction      of the landing-bag-deploy
microswitch     was first indicated    by the telem-                                                                        Ground            Communication
etry   system    as the    spacecraft    pas_d     Cape
Canaveral     at the end of the first orbit.       Since                                              The teletype system circuits     performance    was
this event   is normally    not displ'lyed,    remote                                              good with relativ,dy     few outage 1)eriods.   Traf-
sites were requested   to monitor  this function    on                                             fic flow was exceptionally       smooth,   with trans-
tile events  recorders   for the remainder      of the                                             mission   times   generally    less than    1 milmte.

                            TABLE    A-II.--Telemetry                      Data,   Orbit       1

          Telemetry                           Decommutator                             Slant           range,                        Elevation,
                                                                                        naut.           miles                             deg

                        Loss of                                                    Aequisi-                 Loss        of   Acquisi-               Loss of
Station     of signal   signal             Lock                        Loss         tion      of       L signal               tion of                signal

                                                                                    signal                 __

  BDA       00:03:02    00:10:26         00:03:40                    00:10:26          750             I         868               0                --1.2
  ATS                                        Not    applicabh_
  CYI       00: 14:15   00:21:23         00:14:41                    00:21:20          800                       850            .0                   0
  KNO       00:21:13    00:28:21         00:21:50                    00:28:21          850                       900            -.3                   --.5
  ZZB       00:29:51    00:37:51         00:30:01                    00:38:01          920                       990           --,2                   --.6
  IOS       00:40:02    00:48:31         00:43:12                    00: 46:56        1000                      1040           --.6                 --1
 3I U C     00:49:21    00:57:55         00:49:32                    00:57:21         1020                       990           --.4                 --8
 W O M      00:54:00    01:02:41         00:54:16                    01:02:37          810                      1060           +3                   --1.5
 CTN        01:09:19    01:17:42         01:09:36                    01:17:40          900                      1150           +         3          --4
 ttAW                                         Not       applicable
  CAI,      01:26:41    01:31:23         01:27:18                    01:31:23          840                       920            --       7          --2.1
 GYM        01:26:47    01:33:25         01:27:01                    01:33:15          730                       950            +        9          --2.5
 WtlS                                        Not        applicable
  TEX       01:29:24    01:36:18         01:29:32                    01:36:14          830                       82(I          --.7                  --.6
  EGI,      01:32:00    01:37:05         01:32:1        l            01:37:00          800                       880           --1                  --1.5

                           TABLE    A-III.--Telemetry                      Data,   Orbit           2

          Telemetry                           Decommutator                             Slant           range,                          Elevation,
                                                                                        naut.           miles                               deg

          Acquisition   Loss of                                                    Aequisi-                 Loss of          Acquisi-               Loss    of
Station     of signal    signal            Lock                        Loss        lion of                   signal           lion of                signal
                                                                                    signal                                     signal

  BI)A      01:36:38    01:43:53         01:36:49                    01:43:53          860                       890          --1.2                   --1.4
  ATS       01:51:54    01:58:31         01:53:04                    01:58:21          880                       830            --.2                  +1
  CYI       01:47:55    01:53:58         01:48:11                    01:53:53          850                       910            --.2                   --.2
  KNO       01:54:47    02:01:21         01:55:07                    02:01:21          890                       940            --.6                      --.6
  ZZB       02:04:05    02:10:51         02:04:13                    02:10:51          920                      1040                   .23            --1.       1
   lOS      02:12:17    02:22:09         02:13:27                    02:21:54         1100                      1050          --1.9                       --.9
  MUC       02:22:51    02:31:23         02:23:06                    (12:31:22        1008                       960            --.3                        0
 WO 3I      02:27:36    02:35:45         02:27:45                    02:35:39          950                      1020            +.5                   --1.5
 CTN        02:42:51    02:49:45         02:42:59                    02:49:38          870                       907          --1.5                   --1.3
 IIAW       02:49:01    02:55:19         02:49:29                    02:55:08          940                       830          --1.3                     --.8

  CAL       02:58:11    03:04:48         02:58:35                    03:04:48          880                       730          --1.5                       +.7
 GY3I       02:59:59    03:06:44         03:00:13                    03:06:34          610                       880          +3                      --1.5
 WttS                                        Not        applicable
  TEX       03:03:14    03:09:39         03:03:16            !     03:09:31            810                       810            --.8                      --.4
  EGI,      03:05:35    03:12:07         03:05:46                    03:12:00          670                      1000          +2                      --3

                                                         TABLE A-IV.--Telemetry                            Data,    Orbit 3

                      Telemetry                                                       Deeommutator                      Slall*_ range,                              Elevation,
                                                                                                                         naut.   miles                                   deg

                      Acquisition                   Loss of                                                          Acquisi-        Loss of              Acquisi-                Loss of
       Station         of signal                     signal                      Lock                    Loss        tion of          signal              tion     of              signal
                                                                                                                      signal                               signal

   BDA                    03:09:56                  03:17:03                   03:10:06               03:17:03          870                  900              --1.2                --1.2

                          03:24:44                  03:32:25                   03:25:06               03:31:22          900                  920               --.5                      +.5
   KNO                                                                                      Not      appUcable
                                                    03:56:49                                                           1050              1100                 --1                   --1.4
   IOS                    03:46:55
                                                    04:04:12                   03:56:49               04:04:08         1020                  940                --.7                     -.16
   MUC                    03:56:31                                             03:48:10        /      03:56:30
   WO       M             04:03:16                  04:06:19                   04:03:31               04:06:01           870             1000                 4-1                   --1.4

   CTN                                                                                       Not     applicable
   ItAW                   04:21:49                  04:28:49                   04:22:02               04:24:39           922                 770              --2                   4,.1
                          04:31:17                  04:37:57                   04:31:27               04:37:56           900                 540              --2                 4-3. 6
                          04:33:44                  04:39:,t9                  04:34:04                04:39:39          770                 74O              --5                 --1.         1
   G Y M
   WHS                                                                                       Not     applicable
                          04:36:53                  04:42:32                   04:36:58               04:42:34           930                  603             --3                 --5
   EGL                    04:39:00                  04:42:52                   04:39:21                04:42:48          800                  500             --I                 4"1.4

TABLE A-V.--Telemetry                  Receicer               S gnal Strength,                            TAIqA.; A-VI.--     Telemelry   Receiver                                Sigrt,al
                                  Orbit 1                                                                                Strength,   Orbit 2

                                                                                                                               Estimated              mean,         microvolt.s
                           Estimated            mean,        microvolts

                                                     !                                                                   Low         I                            I
   Station          Low                  Low         I    ttigh          High                             Station    (Receiv,,r       I ReceiverL°W l RH_egiherl(ReH:egihve                        r
                 (Receiver           (Receiver'_      (Rec('iver/(Re      cC ver                                      1, model        12, model       1, model      2, model
                   1, model           2, model       I l, model      / 2 model
                     1415)                                                                                              1415)                 1434)             1415)                1434)
                                        1434)        i    1415),              1434)
                                                                                                          MCC                                 Not  applicable
   MCC                                 Not   applicable                                                   BI)A           25O                   250           250                         250
   BDA               250                 250            250                    250                                                                                                         80
                                                                                                          CYI              4O                   180                    50
   CYI                 75                 120                   25             190                                                                                                         60
                                                                                                          ATS            015                        15                 10
   ATS                                     No      contact                                                                                                                                 50
                                                                                                          KNO              70                       60                 70
   KNO                100                   5O                100                80                                                                 32                 43                  60
                                                                                                          ZZB              71
   ZZB                110                   92                  84             134                                                              150                    80                150
                                                                                                          IOS              40
   IOS                 2O                   8O                  35             150                                       204                    204                  204                 204
                                                                                                           M UC
    MUC               205                 205                259               259                                        100                   130                  200                  100
    WOM               2OO                 200                210               210                                                                                                         35
                                                                                                          CTN              40                       60                 30
    CTN                30                  7O                   25               25                                        90                       50                 60                  80
    HAW                                    No contact                                                                                                                                     160
                                                                                                          GYM             120                   200                   100
    GYM               130                  150                150         1    250                                         80                       50                 80                  30
    CAL                   40                20                 40         1      10
                                                                                                           WHS                     No        telemetry         equipment
    WHS                        No      telemetry          equipnmnt                                                                                                                      2OO
                                                                                                          TEX              9O           ,!         100    ]            70     i
    TEX               100            1 1so I                    90             200                         EGL                     No        telemetry         equipment,
    EGL                        No      telemetry          equipment

 TAm_E       A-VII.                  - Tdemetry                 Receiver              Sigrml                  There          were             2.,048        lines           of         radar         data              automati-
                               Strength,           (_rbit        3                                            cally        transmitted                      by        teletype                 with        only                  15 lines
                                                                                                              in error.                 All        acquisition                     messages                before                   retro-
                                E_timated            mean,           microvolts
                                                                                                              llre        were          dispatched                     to        sites         in     time                 for          effec-
                                                            I                                                 tive        use.
 Station                Low                   Iow           I      High               ttigh
                  (Receiver                (Receiw_r            (Receiver         (Receiver                         Very          good          SUl)port               by         the      voice          network                         per-
                   1, model                2, model             1, model           2, model
                                                                                                              mitted              exceptionally                         fine            communications                                      be-
                     1415)                                                           1434)
                                           1427!__                14151                                       lween              the         Mercury                  Control                   Center                     and            sites
                                                                                                              with         voice         terminat                ions.                 Echo         was          reported                    on
  .M(X;                                        Not, applicable
                                                                                         200                  the         Guaymas                   line         at     the             T-33          voice                 check;                _t
  BI)A                   2OO                    20(} ]       200
  CYI                                           No contael                                                    speaker              was         found             to      be feeding                       back                   into       the
  ATS                      ,ll)                   3(/       [             1o             200                  system.                  Apl)ropriate                      action                was        taken                   to      cor-
  KN()                                                                                                        rect        this     condition                 l)romptly.
                                                  No contact
  IOS                      4O                    125         60                          125
                                                                                         133                                                                Conclusion
   M UC                    64                    104         54
  W()M                     35                     32         (;8                          30
                                                 No contact                                                          It    is concluded                     that         there            were            no       major                  net-
  tI AW                   222                    225        200                          200                  work           problems                  encountered                             during                  the         MA-6
   GYM                     9O                     80         80                           8O                  mission,                   llowever,                     there              were            't      number                      of
   CAL                     8O                     40 _       80                            4O
                                                                                                              minor              problems,                  as        indicated,                     which                   are          cur-
   WHS                               No telemetry                equilnn(,nt
                                                                                         200                  rently             under             investigation.
   TFX                         4O          !     22s _,                   _)o:
   EGI.                              No telemetry                equitmmnt

 CNV         _7                                                                                                                          !                       __          4___L                    2__L                          l__
 BDA                   _- --                                                                                                             i              _               HORIZON-TO-                   HORIZON                     TIME      _
 ATS                             NOT IN        RANGE - FIRST PASS
                                                            7                                     ¢       i                              ___m                          COVERAGE                     TIME
 CYI                                           f--7

 ZZB                                                                             J--7
                                                                      i                                                                                                       !