Surveyor Lunar Lander 1966-1968 (Boeing - NASA)

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Four decades ago the United States and NASA perfected "terminal descent" and the art of landing safely on Earth's Moon. Nothing fancy, Surveyor showed us a lunar surface familar now but unexpected in 1966, and hinted at a Moon selenologists still haven't figured out. Competing for Google's Lunar X-Prize? Read how they made it look easy.

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SURVEYOR MODEL SPACECRAFT A-21A DESCRIPTION , .o. _67- 392 9 0 i _ :E (ACCESSIOlt NUMBER] (THRU) (PAGES) (CODE) C,_(NASA CR OR <_VI96 TMX OR AD NUMBER) 3 I (CATEGORY] ............................. "1 i HUGHES .-.. ......................... / : i NIIliNES SPACE AI|CIAFT SYSTEMS COMPANY 9WISIOII 224848 COPY 1 SEPTEMBER 1964 SURVEYOR MODEL SPACECRAFT A-21A DESCRIPTION HUGHES L ............................ HIIGHES SPACE AIICIAFT SYSTEMS COMPANY DIVISION J JPL950056 This work was performed for the Jet Propulsion Laboratory, California Institute of Technology, sponsored by the National Aeronautics and Space Administration under Contract NAS7-100. CONTENTS Page I, INTRODUCTION Scope Mission General Mi s s ion ............................... 1 I 1 2 4 .............. 9 9 15 15 ........... 17 17 17 19 19 19 20 20 21 33 35 35 38 45 45 45 ...................................... Objectives De scription ............................. ............................. ..................................... DESCRIPTIVE Arrangement SUMMARY II. SPACECRAFT General Basic Payload ........................... ........................... ............................. VEHICULAR SUBSYSTEM Design Concepts Integration AND III. STRUCTURAL Spaceframe Landing Crushable Leg ................................... Mechanism .......................... Blocks .............................. Antennas Mechanisms (A/SPP) ................ ............... Omnidirectional Antenna/Solar Pyrotechnic Electrical Thermal ENGINEERING PROPULSION Vernier Main VI. Engines Retro-Rocket Panel Devices Cabling Positioner ............................ .............................. .......................... ................. ........................ Compartments INSTRUMENTATION SUBSYSTEM ............................... ............................. SUBSYSTEM ................. ELECTRICAL Solar Battery Panel POWER .................................. ..................................... Page Battery Boost VII. Charge Regulator Regulator Unit UNICATIONS Group Decoding Processing CONTROL Control Sun s Sensor Sensor Unit ....................... 47 48 .................. 49 49 54 59 ..................... ........................ 67 67 71 72 77 78 SUBSYSTEM ........................... ................. 79 85 85 Subsystem Experiment Subsystem Experiment Subsystem PROPERTIES ............... Subsystem ................ Subsystem ................... ................... ........... ..... 87 98 104 114 121 129 129 Inertias ....................... ..................... ....................... CONTROL ........................ .................. 129 135 136 139 139 ............................. SUBSYSTEM TELECOMM Data Link ................................ Group Group .......................... ........................... Command Signal VIII. FLIGHT Flight Secondary Radar Roll Attitude APPROACH SCIENTIFIC Introduction Survey Soil Alpha SUBSYSTEM Group ............................. ...................................... .................................. .................................. TELEVISION PAYLOAD ................................... Television Experiment Sampling Experiment Detector Experiment MASS ...................................... of of Gravity Payload Coordinate THERMAL of Thermal Control and Actuator Jets Mechanics-Surface Scattering Micrometeorite Seismometer XI. SPACECRAFT Weight Center Effects Spacecraft XII. SPACECRAFT Methods Combinations System ii Page XIII. OPERATIONAL Prelaunch Transit Lunar APPENDIX APPENDIX APPENDIX A. B. C. Phase Phase Phase Document SEQUENCE AND FUNCTIONAL PEKFORMANCE 143 143 145 18Z 199 205 ....... 215 ................................. .................................. .................................... and Specification Data Between List .................. Characteristics Differences ......................... A-21 and A-21A Spacecraft iii ILLUSTRATIONS Page Frontispiece i-I l-g 1-3 2-I 2-2 3-I 3-2 3-3 3-4 3-5 3-6 3-7 3-8 3-9 5-1 5-2 5-3 5-4 5-5 5-6 5-7 6-1 7-I 7-2 7-3 Atlas/Centaur Earth/Moon Spacecraft Spacecraft Spacecraft Basic Landing Electrical Typical Harness Thermal Typical Thermal Compartment Elements Vernier Vernier Vernier Vernier Main - Surveyor Launch Trajectory Terminal System General Spacecraft Vehicle A-ZIA .............. viii 3 4 7 ....................... ........................... Descent ....................... .................... ..................... Block Diagram l0 II 18 18 ZZ Z3 Z5 Z6 Z7 Z9 30 ....... 36 . . . 37 39 39 4O 41 43 46 50 51 55 Arrangement Spaceframe Leg and ............................... Foot Pad ......................... Device .................. Harness Harness Removal Tray Thermal Switch Disconnect Interconnection Concept ..................... .......................... ........................... Design ................. Assembly Compartment ................................. Dis sipating Capability and Flight ................... Control Subsystem of Propulsion Propulsion Engine Thrust System, Functional Schematic Diagram Assembly Chamber Tanks Engine .......................... .......................... and Spaceframe .............. Propulsion Retro-Rocket ......................... ........................... Block Diagram .............. Retro-Rocket Electrical Command As sembly Power Receiver Subsystem and Transmitter Block .................. Diagram ........... Telecommunications Command Decoding Subsystem Block Diagram .................... iv Page 7-4 7-5 8-I 8-2 8-3 8-4 8-5 9-1 9-2 9-3 i0-I 10-2 10-3 Central Central Flight Altitude RADVS _ADVS RADVS Surveyor Approach Approach Survey Survey Survey Block Survey Survey Command Signal Control Marking Assembly Beam Block Decoder Processor Block Diagram Block ......................... .......................... ....................... Diagram ................. Cover Removed ........ 57 64 68 73 74 75 76 80 81 83 ..... 88 Radar with Preamplifier Orientation Diagram .......................... ............................ Television Television Television Television Television Approach Subsystem Camera Block ................. Diagram Sequence Block ........... ............ Diagram Picture-Taking Subsystem, Camera Functional ......................... Functional 89 TV Camera/Ground Equipment Interface, Diagram ................................. Television Television Composite Video Output Sequence 91 94 97 10-4 10-5 10-6 .............. .............. Picture-Taking Soil Mechanics Surface Sampler Experiment Subsystem, Functional Block Diagram .......................... Soil Mechanics Surface Sampler Instrument Partially Functional Extended Block 99 i01 10-7 i0-8 Alpha Scattering Experiment Subsystem, Diagram ..................................... Alpha Scattering Sensor Deployment iii ........... 113 10-9 i0-i0 Mechanism Potential Scattering Azimuth Mechanical Interference and Surface Sampling Experiments between Alpha ............ Functional 115 I0-ii Micrometeorite Block Diagram View Factor Detector Experiment Subsystem, ................................. of Micrometeorite Instrument Experiment Instrument Payload Detector Instrument 117 Assembly . 119 122 Block Diagram 123 127 134 140 152 154 10-12 10-13 10-14 10-15 II-I 12-I 13-i 13 -2 Seismometer Seismometer Seismometer Atlas/Centaur Lunar Sun Surface Sensors, Sun .......................... Subsystem, Auxiliary Envelope Functional Unit ................. ..................... Temperature Locations Sensor and ........................ Orientation Logic ................ ................ Secondary Orientation v Page 13 -3 13 -4 Typical Typical Transit Standard Transit Operations and Power Profile ....... 157 Compartment Thermal Dissipation During Phase .................................. A and B Temperature Profiles Standard 158 159 165 Magnitude for 166 168 174 176 178 180 of Touchdown 183 13 -5 13 -6 13 -7 Compartments Po s sible Typical Normal Typical Approach Typical Landing ............. Site s ............................. Miss as Function of Midcourse Maneuver Impact .................................. Midcourse Television Retro Sequence of Main Phase Maneuver Geometry Capability 13 -8 13 -9 13-10 13-11 13-12 13-13 .................. ........................ ..................... Velocity ............. of Events Retro Burnout Determination Vernier Maximum Incidence Maximum Landed Lunar Lunar Descent ............................. Allowable Lateral Velocity as Function Angle .................................. Allowable Vertical Center of Gravity Weight .................................. as 13-14 Function of 184 13-15 13-16 13-17 Day Night Operational Survival Capability Capability for Equatorial Landing ...... 187 192 ....................... Landing Hypothetical Lunar Phase Sequence - Equatorial Assumed ...................................... Surveyor Compartments Differences Compartment Vernier Descent Physical Differences 193 Z19 Profile 221 Lunar Day . . . 222 223 ........................ A and B Thermal Tray Temperature .................................... Dissipating Phase Capability Differences Differences, .................... vi TABLES 'Page 3-1 3-Z 7-1. 7-2 I0-i II II -i -2 Pyrotechnic Thermal Portion Time Soil Devices Compartment of ESP Required .............................. Component Data Frame Sampler Summary Weight Installation Frame ............. Zl 31 60 6Z 105 130 130 Commutator for One ................. Data ......... of Commutated Commands Mechanics-Surface A-21A A-ZIA Weight Detailed ............... Surveyor Surveyor Itemized Experiment Payload Summary Attitude Coast Typical Power Expected Vernier Maximum A-21A ..................... Status .................. Payload 11-3 Weight Summary for Each Scientific .................................... Combinations of Operational Control System Summary 137 138 1 1 -4 13 -1 ...................... Phase Modes Provided by Coast ............................ Control Capability 147 156 ....... 160 163 164 170 175 191 ZI6 217 13-Z 13-3 13 -4 13-5 13-6 13 -7 13 -8 Cfl C-2 Phase Attitude ................. During Transit Expected Into Antennas Quality Engine Shade Compartment Thermal Performance .............................. ....................... Modes .................. Equipment Loss ............ ....... of Telemetry Thrust Time Control for Lunar Spacecraft Night Heat Summary Component Weight Differences, Differences A-21 and to A-ZiA A-ZIA .................. .................. of A-Z1 vii &IN A NlDlRECTlONAL rENNA ( 2 ) . - VERhIlER FUEL TANK DESCENT RADAR ANTENNA (LI innu31 I CHAMBER ( 3 ) ATITUDE JET L SURVEYOR S P A C E C R A F T A-21A viii I NTRODUCTI ON S C OPE This A-ZIA model document describes the general The design material and overall performance in the of the of Surveyor spacecraft expected spacecraft. design of the presented document predicts condi- describes the in its present spacecraft Although by state of development under and the performance tions in a when the operated spacecraft realistic specified environment. or design influenced and performance other is conthan those trolled, associated defines constrained, with spacecraft The current of these context the a large number of factors construction in terms of the of the spacecraft itself, design provided this document mechanizaJPL and repre- performance spacecraft and by tion only. sents the description Hughes of those Aircraft A scientific Company complete functional, instruments understanding definition of the design of spacecraft and operation in total interfaces instruments. the numerous performance with operational, administrative that exist is beyond the scope of this document. MISSION OBJECTIVES The Company sion Surveyor under the spacecraft direction for is being of the designed and built by Hughes Aircraft Jet Propul- California Institute and of Technology Space Laboratory The a transit (JPL) Surveyor from the National Aeronautics has been Administration and designed and to trans- (NASA). effect mit spacecraft earth to the vehicle moon, and conceived perform engineering a soft lunar data relative landing, back to earth and basic scientific to the moon's environment characteristics. To date obtain maximum utility, payloads. the spacecraft basic has been designed elements to accommoof structure, provide the various alternative The spacecraft and make telecommunications, capability maintaining to perform two-way power the generation, earth-moon propulsion, transit This and basic flight control a soft lunar landing while communication. grouping of spacecraft elements, designated as the "basic bus," can thus provide transportation, power, and communication services to the designated variety of payloads. The A-Z1 series of spacecraft, which constitutes the first four Surveyor launches, carries an engineering payload. The purpose of the A-21 series is to demonstrate successful transit and soft lunar landing and to gather basic engineering data relative to the performance of the spacecraft in the environments encountered in transit. The collection and transmission of scientific data is a secondary objective for this series of spacecraft. The A-21A series of spacecraft utilizes essentially the same basic bus but carries a different payload, consisting of various scientific instruments. The primary purpose of the A-21A series is the collection and transmission of scientific data relative to the lunar environment. The design and performance of the A-21 spacecraft is covered in HAC document 224847, "Surveyor Spacecraft A-21, Model Description." GENERAL DESCRIPTION Spacec raft The general are and shown arrangement in the of the spacecraft The mounted members. of a tripod of gravity and identification is composed of its various of several of elements electronic thin-walled frame for use frontispiece. assemblies tubular spacecraft on The landing mechanical alloy the a spaceframe configuration gear with constructed of the three space- aluminum by is dictated in the over selection Center foldable low legs soft landing. a wide range of the vehicle Thermal lunar is kept control to obtain stability ment over of landing conditions. range of the of the equip- the extreme temperature surface and (+Z60 ° to -Z60 ° F) active methods. is accomplished This and design thermal by a combination represents design the latest of passive, semi-passive state of the art in the application structures. of structural principles to light-weight space Launch Vehicle The spacecraft boost will be vehicle launched (figure on l-l). vehicle to meet its 66-hour Under transit to the moon by the Lewis by Atlas/Centaur Research General mission. the direction of the NASA designed Center, the Atlas/Centaur is being specifically requirements Dynamics/Astronautics The folded spacecraft the launch within of the Surveyor shroud on is housed a conical breakaway FIGURE 1 1. - ATLAS/ CENTAUR LAUNCH V E H I C L E 3 top of the second and stage liquid Centaur. hydrogen The Centaur, complete with its guidance atop the system, fuel tankage, Atlas rocket. engines, is located directly first stage MISSION Launching and Tracking will Operation originate from boosted nose from JPE by Cape Kennedy, Flight Florida, with computation (SFOF) 60 then inject of will antennas. initial South protranspanel in Launchings and space flight control Upon being Space Operations altitude The l-Z). Centaur gear on Facilities Pasadena. miles, the the the Atlas will be to an of approximately Centaur At the will the breakaway into an thrust shroud jettisoned. (figure the landing spacecraft Centaur earth/moon but extend mode trajectory conclusion phase, that before the separation, spacecraft programmer and the omni generate The commands high-power transmitter is also commanded will occur (DSIF) and are at this time to aid spacecraft Africa vided mission Deep by acquisition. Space Initial acquisition Facility Australia, this phase at the Johannesburg, later Instrumentation at Canberra, during station with tracking Both stations and Goldstone, the California. The Centaur. reception automatically from spacecraft. from solar is deployed at separation of the spacecraft POSITION OF MOON AT IMPACT I TOUCHOOWN TOSUN PHASE RETR0 ,,N,T,ATE0\ \t _ / _ / GOLDsTONE _ / _ _ AT 60 NOMINAL MILES RANGE FROM OF _ _ l t MOON) _L _..'a', ............ mlJlr.t.vluN SEPARATION _ Anli,I/ / / _jl-..("._1 • ._1_. ":'/ / "_ ..."- _ET.OMA__U_VEpS _" ; / "_-_ \ • _X X OTHER MINUTE REACOUISITION OPERATIONS S BEFORE SUN T A_ (NOMIN&LL¥ TOUCMOOWN, AN{) _i 30 , 4# ///I OF ACQUISITION / SUN ACQUISITION (NOMINALLY <1 AFTER LAUNCH / HOUR / STAR ACQUISITION AND VERIFICATIO_d (NOMINALLY 6 HOURS AFTER LAUNCH) M,DCOURSE CORREC ,ON) ,o _ _ _ _,_ \'POSITION MOON AT OF LAUNCH MIOCOURSE CORRECTION (NOMINALLY I_) HOURS AFTER LAUNCH) FIGURE I-2. EARTH/MOON TRAJECTORY Midcour se Correction Three reaction and gas track jets, the located sun and on the the star a landing Canopus. gear legs, When position the space- craft to acquire lock which The on the appropriate system is established sensors in space maneuver. begins Tracking and from used to these will celestial be points, space coordinate maintained direct sun thenceforth panel automatically to achieve until the midcourse illumination and battery are and charging. processed solar is oriented energy for from to generate data by electrical spacecraft the DSIF operation tracking received in sequence stations Upon radio SFOF the to compute spacecraft thrust and the midcourse turns through correction. a series command to align The earth, of angular maneuvers vector. the vernier required from engine magnitude axis relative for to the spacecraft velocity direction the midcourse maneuver where is transmitted it is received vernier and the Goldstone Then tracking station command to the spacecraft, causes three stored. engines time. which the star the execute liquid-fueled for rocket of to operate This will action ultimately at a specific provides bring average thrust level a specific spacecraft landing period a midcourse the vehicle alteration to the the of the trajectory area. the sun After and the selected spacecraft lunar midcourse Canopus correction to maintain is completed, its previous reacquires attitude. Terminal Descent and Soft Lunar 66 hours Landing launch, tracking the spacecraft the approaches spacecraft the moon. changes attiA Approximately Upon tude command to align the from after the Goldstone station, with the thrust of its re'tro-rocket camera views spacecraft surface area velocity during vector. downward for the looking purpose television the moon's the approach As the of transmitting the moon radar pictures of the landing speed back 9000 to earth. feet per spacecraft the altitude approaches marking delay, at a relative a signal of the of about range second, which, generates at a slant solid ejects of 60 miles, main after motor. from a suitable This the initiates and ignition propellant the altitude the retro-rocket radar At out, an its At ignition subsequent and burning marking retro-rocket of approximately nozzle begins feet, to decelerate the main spacecraft. burns altitude empty this 40,000 from the retro-rocket and case point is separated the spacecraft signals system spacecraft enoughto approximately the and surface doppler of the 8 seconds moon later. is close from are to receive system. to control reliable Signals control from its altimeter processed by velocity radar this the fl_ght control electronics the throttle valves on the three vernier rocket engines to maintain the proper attitude and rate of descent. The spacecraft continues to decelerate until at an altitude of 14 feet, the vernier engines are turned off. At this time both horizontal short and vertical components to the gear and of velocity surface are small. The with the This spacecraft landing sequence falls the shock is illus- remaining by distance of the moon absorbed trated the landing i-3. the crushable blocks. in figure Lunar Operation After landing panel on the to the surface of the moon, line the and spacecraft the high-gain is commanded planar one array of the to the with the survival on to mode to align antenna the solar to the spacecraft-sun line. spacecraft-earth to the planar array will solar Subsequent and commands connect transmitters (high power or low antenna provide panel switches that transmitter consistent power) from which the a usable and battery. bandwidth After available initial touchdown can be turned conformation, provide subsystem. the various payload experiment subsystems via information relative to the lunar environment the telecommunications FIGURE i-3. SPACECRAFT TERMINAL DESCENT pI:kECEDING PAGE BLANK I_40T I:IL_ED. II. SPACECRAFT DESCRIPTIVE SUMMARY GENERAL ARRANGEMENT Design launch vehicle, of the the Surveyor established and the spacecraft DSIF nature and is dictated Space-flight by the configuration of the Operations mission. reliability, a high Complexes, The use of reliability objectives, design of the spacecraft of proven toward state-of-the-art ance succes of unproven s. Figure midcourse, The principal 2-i and criteria, or components and the avoidof circuits designs, contribute probability is a basic post-landing block diagram of the spacecraft are system. shown The stowed, 2-2. configurations the system of the A-ZIA are listed in figure elements comprising below. Surveyor Spacecraft Subsystem Elements Structural Spaceframe--provides Landing Crushable mechanism Antenna/Solar toward the Leg Mechanism the basic -- absorbs part and Vehicular Subsystem spacecraft. of the after shock of landing. large landing leg structure major of landing for the portion shock Blocks -- absorb relatively deflections. Panel earth and Positioner the solar (A/SPP}-panel toward actuate switches, spacecraft orients the the planar array antenna sun. separation and nuts, tank Pyrotechnic valves, Electrical Thermal thermally Devices -- mechanically power control pin pullers, locking units. electrical Cabling-- plungers a detonator. interconnects -- provide units. Compartments sensitive temperature-controlled environment for SPACECRAFT •O"T'CAL NER"'L i "N0 ' SE_,NG LUNAR (RADARS) VELOCITY AND ALTITUDE_--_-Ib.J l • I I:ATTITUDEVELOCITY _L,GH+ CONTROL ) 'NO I CONTROL J t I I [ MIDCOuRSE PROPULSION MANEUVER RETRO MANEUVER • t ELECTRIC • POWER CONTROL ENERGY STORAGE POWER SOURCES _J I • TRANSMIT AND RECEIVE • TELECOMMUNICATIONS COMMAND DISPERSAL • SIGNAL AND PROCESSING SWITCHING I • AND • I • • SCIENTIFIC PAYLOAD APPROACH TELEVISION ENGINEERING • MONITOR FUNCTIONS INSTRUMENTATION BASIC BUS INTEGRATING WIRING STRUCTURE MECHANISMS AND CONTROL VEHICULAR : SIGNAL AND POWER FLOW • STRUCTURAL THERMAL TO DSIF FIGURE 2-i. SPACECRAFT SYSTEM BLOCK DIAGRAM Engineering Temperature frame status and and Acceleration performance. Sensors Instrumentation -- provide for earth monitoring of space- Propulsion Vernier trol Enginessupply reaction burning, forces and for midcourse and velocity correction, control attitude during con- during retro-rocket attitude terminal descent. Main Retro-Rocket-decelerates spacecraft on approach to lunar surface prior to final descent. I0 ® ANTENNA SECONDARY SOLAR SENSOR & SOLAR POSITIONER PLANAR SOLAR PANEL ANTENNA ARRAY MICROMETEORITE SENSOR LANDING MECHANISM GEAR -3 RELEASE REG TV CAMERA (SURVEY) NO. S TV CAMERA (APPROACH) NO. 4 / CRUSHABLE BLOCK ALTIMETER/VELOCITY SENSING ANTENNA ® POST LANDING CONFIGURATION fl-I ® (I-2. ® 32.774 DIA "l SOLAR PANEL , PLANAR ARRAY / ANTENNA RELEASE S REQD MECHANISM /CENTAUR INTERFACE ALTITUDE MAIN ROCKET RETRO ENGINE MARKING ANTENNA SPACECRAFT INTERCONNECT STRUCTURE ADAPTER FIELD JOINT _ ", 104.704 MOUNTING FLANGE ATTACH STATION /" CENTAUR DIA _ (_ THERMAL D,APHRAGM STOWED CONFIGURATION FIGURE 2-2. SPACECRAFT GENERAL ARRANGEMENT Electrical Power Solar Main Battery solar Boost Panel-- charges battery and powers energy controls spacecraft storage and for during the transit spacecraft. and lunar day. Battery--provides Charge panel. Regulator (BR)-Regulator electrical (BCR)-- regulates battery charge from converts unregulated battery power to regulated power for spacecraft. T ele communications Transmitters and scientific (Z)transmit data engineering from lunar telemetry surface. earth-transmitted unit. Also commands two-way and route data in transit and engineering payload Receiver/Transponders these commands to the (Z)-- receive central with decoder provides doppler tracking Antennasreception landing Central mand control Signal in conjunction two and and transmitters. antennas antenna for for data transmission band data and command during omnidirectional one planar phases. Unit-and five contains subsystem and array wide transmission lunar Decoder decoders on-off a receiver-decoder decoders selector, earth two central comand that process operations. and verification commands operations gather provide Auxiliary-- time-interval engineering signal Processorsand Rate the signals telemetry. from various subsystems Low Data appropriate provides limited conditioning for at low for transmission information bit rates for use with low-power transmitter and bandwidth. Flight Inertial craft eration Primary once sun Reference Unitcontrol for provides of optical Control rotational sensors. reference Also while an spaceaccel- three-axis or radar is not under reference Sun provides spacecraft provides is obtained. flight. for accurate control of the spacecraft roll axis Sensor-- acquisition 13 Inertia Switch-- closes at a nominal g level to predict retro rocket burnout for retro ejection timing. Canopus Sensor-- identifies attitude control reference. and tracks the star Canopus for accurate spacecraft Flight Control Electronics-- processes guidance signals from the flight control sensors (inertial, optical, and radar) for stability and maneuvering. Secondary Sun Sensor- makes initial sun detection for gross alignment of spacecraft roll axis during transit, and for solar panel positioning toward the sun during lunar operation. Radar--the altitude marking radar (AMR) initiates firing of the retro-rocket on approach to lunar surface. The radar altimeter and doppler velocity sensor (RADVS) measures slant range and three-axis velocity of spacecraft during descent phase, controlling the rate of descent and attitude via the vernier engines. Attitude Jet System-- provides reaction forces for spacecraft orientation maneuvers and attitude control during period from Centaur separation through preretro- rocket firing. Roll Actuator--provides Vernier Engine No. 1. Approach Approach of I000 Television miles to about Camera-80 miles Television Subsystem of lunar surface from a range roll control moments during vernier engine thrust, via provides above pictures lunar surface. Scientific Survey surface, Television free Experiment and of the Subsystem spacecraft Payload -- provides after pictures of portions of lunar space, Surface of the landing. determines the mechanical Soil Mechanics characteristics Alpha surface Scattering elemental Samplerlunar qualitatively surface. Subsystem-gathers information to determine lunar Experiment composition. Detection impacting Micrometeorite micrometeorites Experiment--measures the lunar surface. lunar ejecta resulting from 14 Seismometer moon, Experiment Subsystem -- measures physical disturbances on the BASIC DESIGN CONCEPTS The primary design objective has been to maximize the probability of successful spacecraft operation within the basic limitations imposed by launch vehicle capabilities, the extent of knowledge of transit and lunar environments, and the current technological state of the art. In keeping with this primary objective, design policies have been established which (1) minimize spacecraft complexity by placing responsibility for mission control and decision making on earth-based equipment wherever possible; (Z) provide the capability of transmitting a relatively large number of different data channels from the spacecraft; (3) include provisions for accommodating a relatively large number of individual commands from the earth; and (4) make all subsystems as autonomous and independent as practicable. These basic design policies complement each other and provide a large degree of flexibility in controlling the real-time operation of the spacecraft. Complete control of spacecraft operation is achieved through a loop that is closed through earth-based equipment and decision-making processes. The only portions of spacecraft operations that are not subject to this earth/spacecraft control loop are those associated with certain portions of the attitude stabilization and terminal descent phases, and solar panel deployment where earth control is complicated by requirements for critical timing. Although this design concept places greater demands on earth-based eq'uipment and facilities, it provides flexibility in control and data-transmission adaptability and growth potential. This concept enables the same basic spacecraft design to accommodate a wide range ofpossible payloads and missions. PAYLOAD INTEGRATION series of Surveyor spacecraft vehicles has been designed to experiment subsystems: The A-ZIA accommodate the following a. b. Survey television experiment subsystem. subsystem. Soil mechanics surface sampler experiment c. Alpha scattering detector experiment _:_Instruments furnished by JPL subsystem. _',_ 15 d. e. Any primarily Micrometeorite Seismometer combination by the total detector experiment of experiment injection weight experiment subsystem. subsystems capability the subsystem. * may of the be * accommodated, vehicle. wide on the spectrum spacecraft is Hughes the limited launch Flexibility different various through cally for electrical scientific the use is provided and to accommodate requirements in a typical auxiliary An the experiment spacecraft electrical units potentially imposed of by the functional instruments of electronic instrument. between normalizing experiment necessary payload. designed auxiliary basic signals for the bus This and unit and flexibility built provides a particular the two. by achieved specifi- each electrical] instrument functional by interface and the conditioning When between a specific desired only complement to remove which to adjust spacecraft auxiliaries has and been other In of determined, elements some cases it is of the appropriate are the being experiment also be subsystems necessary This deleted (off lateral loaded). center it may spacecraft the exact gravity by adding experiment ballast. approach permits definition of the complement st cycle. to be delayed until relatively late in the spacecraft fabrication/te *Instruments furnished by JPL 16 III. STRUCTURAL AND VEHICULAR SUBSYSTEM The mal structural and electrical vehicular subsystem provides mechanical support, actuation, This blocks, subsystem alignment, and ther- protection, for interconnection, and leg its touch-down includes the stabilization basic antennas electrical SPACEFRAME The mounting structure, mal control trates tubing, around points provided spaceframe po s itioning LANDING The intermediate landing the forces the spacecraft landing components. crushable positioner, spaceframe, mechanisms, cabling, mechanism, panel compartments. omni-directional devices, antenna/solar and thermal pyrotechnic spaceframe surfaces the main and is the basic structure for the the vernier mast, and spaceframe interconnected points structure, of the landing spacecraft. gear, and control payload. up of thin the It provides Centaur interconnect tanks, group, Figure wall 3-1 therdescent illus- attachments rocket, retro crushable engines flight scientific is made to form for the and mast antenna is associated sensor compartments, radars, the basic the retro the at the and flight blocks, sensors, The control spaceframe. frame rocket. Centaur corners supports m. members aluminum with the for a modified rocket, leg hinge to the panel hexagon attachment points top of the a are Attachment interconnect of the the frame. planar retro landing attached and solar The array through m echanis LEG landing MECHANISM leg mechansim the and shock (figure absorber, 3-2) is the maintain The landing control with absorver, made footpad, attitude legs jets. the up of the and the landing lock leg, strut. and long absorb radius leg is footand the The A-frame, lep_ footpad, of impact points for shock absorbers stability provide The landing during the touchdowr_ cold gas attitude spaceframe shock attachment hinged pad to the attached lower to the corner outer of the end. The aluminum intermediate honeycomb A-frame, 17 FIGURE 3-1. BASIC SPACEFRAME FIGURE 3 - 2 . LANDING L E G AND FOOT PAD 18 lock strut are interconnected to permit folded stowage of the landing gear by telescopic action of the lock strut. Torsion springs at the leg hinge extend the legs when the squib-actuated pin pullers are operated on Centaur command. The legs can also be extended by earth command. The lock strut locks in the extended position and forms, with the shock absorber, a straight line member from footpad to the spaceframe upper corner. The hydraulic shock absorber compresses with landing load and absorbs the landing shock. Crushing of the footpads absorbs some of the impact energy. After landing, the shock absorbers are locked in place by squib-actuated pin pullers. CRUSHABLE BLOCKS The crushable blocks of aluminum honeycomb are attached to the bottom of the spaceframe at each corner to absorb part of the shock of large landing loads. The blocks contact the lunar surface upon occurrence of any relatively large landing leg deflections and absorb energy by crushing. OMNIDIRECTIONAL ANTENNAS MECHANISMS The omnidirectional ("omni") antennas are mounted on the end of folding booms, hinged to the spaceframe, with omnidirectional antenna boom A near landing leg 1 and omnidirectional antenna boom B near landing leg 3. The omni antenna booms are stowed by folding against the spaceframe. Pins retain the booms in the stowed position and squib-actuated pin pullers release the booms on Centaur command. Torsion springs deploy the omni antenna after release. Omni antenna boom release is effected by a command from Centaur after the landing leg is extended and locked into position. Earth commands can also initiate omni antenna boom extension. ANTENNA/SOLAR The the mast tion with one A/SPP PANEL connects POSITIONER (A/SPP) array and solar panel to the top of has three The axes of rota- the high gain planar The planar by hinge connections. respect to the mast: array antenna roll, polar, and elevation. array solar panel has Stepping motors This the axis of rotation with respect to the planar in response antenna. rotate the axes freedom earth in either direction permits to commands array from antenna earth. toward of movement orienting the planar and the solar panel toward the sun simultaneously after landing. 19 PYROTECHNIC The and and valves quantity no DEVICES devices in table 3-1, All for mechanically which lists the devices safety actuate items, are design the their vased mechanisms, locations, on the switches, functions, "1 watt, A total of pyrotechnic listed required. fire pyrotechnic range 1 ampere, 36 pyrotechnic 5 minutes" is used. requirement. devices CABLING electrical ELECTRICAL The correct the cable tunnel heat in the cabling power interconnects flow. Cable the design installed the spacecraft permits wire is and routed To "tear contains unregulated pin puller aluminized shows the components installation cable or connectors. to provide removal The of signal and by assemblies connecting to minimize losses wall disconnecting the two heat the thermal loss lunar from night, A. pre from from the compartments the compartments. through further a thermal minimize during a disconnect tear strip strip" leads is installed for RADVS and the 22-volt tear power, power strip, of compartment squib On one flows power, This 19-ampere return. removing tion after then SS & A 22-volt the DSIF, a squib power, separates Mylar command part compartment. the hole. from or Figure the The 3-3 thermal super-insulabefore and in to close Cables inserts the tear Figure disconnect contain wires actuation. wire through lunar The night. scientific exiting (nichrome strip) 3-4 compartments wire) loss from harness. designed installed or the or around in all the thermally {except during insulating those the perma-nickle heat the to minimize illustrates of the compartments wiring is be payload each spacecraft may five experiment individually bus, in the except vehicle subsystem without for when {figures four weight an installations, effect and on other of which removed basic left are B for to the can bus be experiment To subsystem minimize is subsystems the removed, is wiring cable reliability television disconnect installed from amount spacecraft weight balance. of cable experiment 3-4 and 3-5). individual harnesses employed each experiment or assemalso use of A connector All in compartment the spacecraft that basic experiment is without The subsystems. contained subsystem removed blies. external in a separate the the survey as TV assembly of the installed compromising for connectors harness harnesses bus experiment points. subsystem basic 20 TABLE Type Pin Puller 3-1. PYROTECHNIC DEVICES L oc ation Quantity 2 3 panel locks 7 3 1 1 3 2 2 3 1 absorbers 3 4 auxiliary} Omnidirectional Landing Planar Alpha leg locks antennas antenna/solar scattering deployment sampler device Soil mechanics-surface Electrical Separation Valve nut harness disconnect Retro-rocket Helium Nitrogen attachments operation tank valves tank valves leg shock tank valve leg shock power absorbers Locking plunger Landing Nitrogen Locking plunger electrical switch Landing RADVS Pyrotechnic controls mechanism (engineering Ig nito r Cable clips. Slack assemblies cabling Retro-rocket are attached to the spaceframe mechanically by suitable brackets The and is provided is established harness legs around active points. connector Centaur as electrical interface through I. The a 5Z-conductor connector mounts assembled of the part of basic spaceframe bus wiring between on the bottom landing 1 and Z and mates with a Centaur connector when the spacecraft THERMAL Two items is mounted. COMPARTMENTS thermal compartments control (A and B) are provided is needed equipment throughout in these to house electronic (See figure is mounted 2-Z for which thermal the mission. compartments for compartment on a thermal A thermal surface tray placement. ) The (figure 3-6) which distributes heat throughout the compartment. the lunar of shell surrounds environments the entire compartment An to isolate it from composed (figure 3-7). insulating blanket, Zl a ) B e f o r e Actuation b ) A f t e r Actuation F I G U R E 3-3. ELECTRICAL HARNESS DISCONNECT DEVICE 22 --__ L .... 1 [ .... 1 F-_.--1 J L __'___S L .... __J _ Fi_-_ JL___ T - • ! rTwu-] I_NI I .A- I L. .J I .n. I l Ii=_,i ,l TR _MITTER _RF _-TRAN_I, ilTTF.R SWITCH I _TCH I I I I "_" I _UXlU_ I II _L_.,_ IIII ; I I w'_I'_ i, F_ • m _2_. _ I _At. I lurxu L______J _-¢ I 2._ -/ qL_lLq_lLq &l_pt_y &N_/SOLAR _ POQITIOqRR &N O L(3CKS ...................... I ..................... _ so_ L.-__ _L J I ] I l ] I L COMPARTMENT B ,z_ -E SPACECRAFT SUBJ£CT SELECTION TO PAYLOAD PAYLOAD WIRING 1 I _,cK 0_C_ECT I ® c_Ecm_ To K _s,_op _ a N_s FIGURE 3-4. TYPICAL HARNESS INTERCONNECTION MICROMETEORITE SENSOR SEISMOMETER SENSOR i NICHROME WIRE M ICROMEEl ELECTRONICS SEI SMOMETER ELECTRON I CS ALPHA SCATrERI G N DEPLOYMENTl N P PULLERS SURFACE SAMPLER HARNESS SUPPORT DETAIL ALPHASCATTERI NG SENSOR RTMENT B WALL MI CROMETEORI TE AUXILIARY SEISMOMETER AUXILIARY THERMAL SPLICE AREA AUTONOMOUS HARNESSES, ONE FOR EACH EXPERIMENT SUBSYSTEM INTERFACE DISCONNECT, SCIENTIFIC PAYLOAD BASIC BUS (WITHIN COMPARTMENT B) CENTRAL S IGNAL / PROCESSOR SURFACE SAMPLER AUXILIARY ALPHASCATTERING AUXILIARY BOOST / REGULATOR CENTRAL COMMAND DECODER / / SCATI'ERING ELECTRONICS COMPARTMENT B POWER BUS / / BASIC BUSCONTINUATION (TYPI CAL) ALLSCIENTIFIC PAYLOAD WIRING THIS SIDEOF INTERFACE SCONNECT DI IS INTEGRAL WITH BASIC BUSWIRING ENGINEERING SIGNAL PROCESSOR FIGURE 3-5. HARNESS REMOVAL CONCEPT 25 I I MAIN " ENGINEERING MECHANISMS AUXILIARY BATTERY THERMAL CONTROL AND HEATER _ECEIVER TRANSPONDER B BATTERY CHARGE REGULATOR RECEIVER TRANSPONDER A TELEVISION AUXILIARY E L ECTRON IC S _"_......._ MICROMETEORITE DETECTOR AUXILIARY _ \" _, . ,"_Z '__" / / / BOOST ,_. f _"_ /SIGNAL PROCESSOR ALPHA SCATTERING ,/_e,,_ / _ ./') ELECTRONICS THERMAL CONTROL -AND HEATER _" X _ ALPHA SCATTERING _ _ AUXILIARY LOW DATA RATE AUXILIARY / REGULATOR FIGURE Z6 3-6. THERMAL TRAY ASSEMBLY ,.,.q I t'-.- A c¢ 0 t-. ,,_ J 0 00 .J o., w 1Iw "Y'¢o Z; oO ,f, f..4 Z; f..4 (,0 qr'_ ¸ z 0.., U b.-- I-I-- I1: ne n J :)J 0 L) f..4 l" \ a.I,OI-ar ar o I, I a. L 0._ I.-- ,.4 L) I o'3 r..4 o I--I [..q o Zr_ n_ i,.uJ_ n 1 D_ o0o _d \ \ ,.,,. z,,,. _ o,.. =) -J I I t_ "0 u 0 _ "_ ,r.-t i1) _._ FIGURE 3 - 8 . T H E R M A L SWITCH 29 8O I u_ I-,,::I 3 60 COMPAR 6l o 43 ° _z 123.5 ° _ ao 13"5° 6 ° 4o =1.--0 SOLAR LUNAR NOON i 30 INCIDENCE ANGLE, 60 11, DEGREES go FIGURE 3-9. COMPARTMENT DISSIPATING CAPABILITY 3O TABLE 3-2. THERMAL COMPARTMENT COMPONENT INSTALLATION Compartment Receivers Transmitters Rf SPDT (Z) (Z) A Central Boost Central auxiliary Compartment command regulator signal processor B decoder switch Signal processing switch Engineering Low data signal rate processor Rf transfer Battery Battery auxiliary and heater Thermal charge regulator auxiliary temperature a s s embly Resistor, control thermal sensor calibrated Engineering Television Thermal assembly Resistor, temperature Meter Wiring shunt harnes mechanisms auxiliary'_ Wiring control and heater harness, compartment surface sampler B Soil mechanicsauxilia thermal sensor calibrated Seismometer Seismometer Micrometeorite auxiliary':-" Micrometeorite electronics-':`" Alpha Alpha scattering scattering r y::`" auxiliary::-" electronics::' detector s, compartment A detector auxiliary::-" electronics::-" ":-"Part of scientific payload. 31 PRECEDING PAGE P_,LANK NOT FtL_,',__. IV. ENGINEERING INSTRUMENTATION Temperature ing of spaceframe sensors, of platinum 5. 0 ma provided contained a basic and status sensor, acceleration and and sensors are There provided are two both for telemetric monitor- performance. a high The accuracy types of temperature are made with are are up a sensor, of which are resistance current wire. source constant basic temperature accuracy The sensors provided sensors constant with and the high temperature constant a 2.5ma current source. current sources in the ESP. all of There which These have are the sixty-three capability are temperature of being monitored sensors while included still on units in the the as basic bus, pad. launching follows: sensors distributed control s among the spacecraft Flight M units 7 sensors 3 sensors 6 sensors e chani sm units Radar Electrical T ransmitte Approach Vehicle Propulsion Survey Accelerometers, loading of the points leg 3. and displacement TV power rs TV structure units units 3 sensors Z sensors 1 sensor Z5 sensors 15 sensors ] sensor switches, during are the FCSG. andpotentiometers the thrust, near the transit, are and installed landing to measure Three phases. accelerometers and one on installed retro-rocket/Centaur amplifiers system are attachment on landing +15 g peak. points. Accelerometer accelerometer by and installed Full-scale of the range of the legs is approximately at the Position Full landing of the is measured lock struts a potentiometer omni antennas leg hinge by extension landing is indicated 33 mechanism-actuated to inhibit switches. Lock strut l has an "omni antenna extend" switch omni antenna extension until landing legs are fully deployed. and descriptive A, items documents iI thru 13. for the engineering instrumentation Definitive are listed in Appendix 34 V. PROPULSION SUBSYSTEM The maneuvering phases and propulsion the subsystem components supply the reaction and forces lunar for landing spacecraft during 5-i the midcourse illustrates the correction elements of the mission. control Figure of the propulsion flight The subsystems. subsystem consists of three-hypergolic-fueled vector correction engine The for and variablelanding the propulsion engines thrust, phase vernier maneuvering for midcourse a solid force by and velocity and propellant retro-rocket maneuver. supplying principal subsystem commands deceleration is controlled from earth, during flight the landing control through initiated propulsion maneuver sensor s. preprogrammed by flight control maneuvers signals. VERNIER The midcourse rocket descent chamber fuel tanks, and the ENGINES vernier maneuver engine to the burning, lunar engine system (figure -5-2) supplies the reaction control forces during during for retroterminal thrust velocity and surface. and oxidizer valves vector correction, vector vernier and attitude attitude system system helium operation, over using velocity The control engine The feed consists of three assemblies three a feed tanks, for system. is composed tank, and propellant of three lines, a high-pressure arming, be throttled valve Engine valves necessary thrust by system can deactivation. of approximately signals supplied by flight conoperate cool30 by The of each engine a range control a bipropellant Appendix throttling ]5, item Z7). flight control (see firing is accomplished by the solenoid-controlled, trol. Throttling from to clear helium-actuated valves a are controlled on/off controlled while the individually valves The oxide on/off valves engine collectively ing (NzO The jacket single out signal. Vent permit oxidizer (NO) purging of the decomposed by volume gases. nitric is nitrogen the tetroxide freezing ). Fuel point. and 4) with fuel I0 percent to depress is monomethyl ignite hydrazine when .n_onohydrate mixed in the (72 MMH. thrust 28 H20 chamber. oxidizer hypergolically 35 -Z SUN SENSOR SECONDARY 00PPLER ANDALTIMETER VELOCITY RADAR ANTENNAS DOPPLER VELOCITY RADAR ANTENNA +Y +X l 30 d_ ROLL F_" / / _'_,/ L_.J YAW _L F--_ J _ vERNIER ENG,NE JETS /L'-'J O_RO LEG 2 _ _A_ _ t"_ \, __ _\ _j PR,MARY _ SENSO R \ _ _n P,,_ ",,\ -y U C'I _ERN,ER _ _ _G'_ _ 30 d RETRO-ROCKET ENGINE LEG 3 NOTE: I ALTITUDE MARKING RADAR I_FOR FIGURE BEAM ORIENTATION,SEE 8-4 C) I ÷Z FIGURE 5-I. ELEMENTS CONTROL OF PROPULSION SUBSYSTEM AND FLIGHT 36 _,__=3____._= ......... 8EU_/= VALV_ 3U ] d I _$/_zLr _E OItlD/ZER I ,_0¢¢. _WlCO/.O I |_ I I = _ I_' Ip, -- I I ii II II ) _2OPELLAN'I" ,_ _[ ,'" _ _ / ,, I ,_ T Z<_ ..... : . ..... _ _ _ _ I . ,: .... z _] ......... _1_ I I _a r_,_orr_c VA L VLr _J ,r_ _ ,, u _O,_LLANT ,, #N-#,¢/: WLV.= ...... _ ....... _-_2V ,_ _ II II i _ ' :j-, II :l .... r-/,z> U _ ',' ,' ;, I', pzo .... .... -'-, ,E_U. I I I ' Z " d ,#o,,"_ mo.,_='_#.. LEGEND i HEATE_. ..... E_-E_T_I_AL _ <_-- E_J'_ ,_._N_O V_I.t_E YALk_ d =$ VAL VE _R_ITED O _E_jL,=TO, I O -...... ..... O,t FUEl. /HECHAN/CAL _ R_DP_DTI_W. EL_'CT'R/C V_ILY_ _ _ re,, CI41_C1_ _4LV_ FIGUt_E 5-2. VERNIER PROPULSION SCHEMA TIC S-YSTEM, DIAGRAM FUNCTIONAL 37 The of the three is hinge engine control specific thrust ing thrust chambers legs (figures 5-3 and 5-4) are located near the Number hinge points landing on the bottom on an of the main spaceframe. motor 1 engine to rotate spacecraft The (swivel) about moment impulse of each mounted in the electro-mechanical x-y plane for roll actuator The an axis arm and engine The spacecraft engine roll control. 36 inches thrust. installed The on of each is approximately vary by with engine gages in length. approximate each and engine feed total impulse is monitored control strain mount- bracket. the thermal design of the vernier of the system engine between preventing system 100°F freezutiliz- maintains during ing ing or temperature periods, by of all portions from launch 0/° and nonthrust overheating to touchdown, and propellant controls a combination and electrical are of active and solar passive thermal surface Other coatings system heating. isolated from the source pair spaceframe nor heat to sink. near components thermally acts ensure Fuel each that the and spacecraft are and each structure contained tanks and as neither tanks an a heat with oxidizer Fuel in three each one of tanks engine. line oxidizer have interconnecting The arrangement and some propellant of the segments temperature the helium data for tank, DSIF tanks of the manifold on the system to all tanks is illustrated all engines. 5-5. spaceframe lines are in figure heated sensors Tanks, propellant from and electrically Thermal line to condition on all tanks, the propellant all engines, Z0 ° to the three 100°F. propellant Fuel and segments tanks permit each telemetering positive complete Helium thermal expulsion monitoring. which assure valves sources. into the lation Appendix deflate oxidizer the central under units tank contain to permit bladders and dump current around standpipe zero-g activated gas expulsion release and propellantcohesion are squib-operated The thrust helium chambers. and 27. conditions. by 9.5 ampere pulsed to force constant stores Valves under pressure the propellants system, is given reguin permit of residual release helium. of helium Tank to the capacity of pressure, B, item dumping MAIN RETRO-ROCKET The main retro-rocket of the (figure 5-6), which lunar performs landing nozzle. the major portion of the deceleration solid-propellant spacecraft during maneuver, is a spherical, unit with a partially submerged 38 FIGURE 5-3. VERNIER ENGINE ASSEMBLY FIGURE 5-4. VERNIER THRUST CHAMBER 39 1 P I FIGURE 5-5. VERNJER PROPULSION TANKS AND SPACEFRAME 40 14 IS 1 : 01 FROM :E OF RE1 TRO GINE. FIGURE 5-6. MAIN RETRO-ROCKET ENGINE 41 The leg hinges, the unit is attached with nozzle explosive flange gas at three nut provide pressure points on the main spaceframe ejection. altitude near the landing clips radar. the release Com- disconnects attachment ejects for post-firing points the for the Friction marking when retro source. around Retro-rocket retro firing igniter sequence operate by altitude marking squibs radar and is initiated. from a pulsed Retro-rocket 19-ampere system. device ignition explosive mands are The Eastern rocket tion and nuts constant-current initiated the flight safety has dual control arming retro-rocket Test Range) and (required by the Air for safe are firing and Force the retroactuaBoth firing provisions single for bridgewire local and of the squibs remote squibs igniter. remote and In addition, indication electrical arm of inadvertent isolation exists firing included. and pyrogen mechanical igniter between squib initiator in the The safe condition. with 1332 the ib sec propellant, pounds. The range B, illustrated engine in cross may section vary The from by figure 8000 to 5-7, retro-rocket weighs I0,000 impulse A pressure approximately pounds over thrust temperature (see Appendix on of 50 ° to 70 °F. item 27). surface sensors ignition. engine blankets, above the required total is 50,000 strain gage is installed during the motor Three case thermal before for telemetering installed case for information retro-rocket thermal on firing. are monitoring The depending to maintain ignition. engine nozzle design temperature of the control thermal spot" retro-rocket insulating is completely and surface passive, coatings of its own "cold capacity, propellant the Because temperature through will be 17 ° F at the time of the thermal the only. gradient engine and at the the prelaunch three grain engine will be temperature, points 17°Ftemperature The bulk temperature reached attachment above of the propellant +50 ° F. The retro-rocket nozzle engine is of spherical overall and length. conventional The design The utilizing engine grain case a partiallyan existing nozzle steel submerged PBAA has to minimize propellant and utilizes composite-type a graphite with throat an geometry. The a plastic exit cone. phenolic is of high-strength case at a low insulated ture level asbestos-filled burning. to maintain the tempera- during 42 FLIGHT WEIGHT CASE THRUST SKIRT STRUT PROPELLANT • INSULATION COLLAR PYROGEN NOZZLE ATTACHMENT BOLTS INSULATION SAFE ARM AND DEVICE NOZZLE THROAT ALTITUDE NOZZLE ASSEMBLY FIGURE 5-7. RETRO-ROCKET ASSEMBLY Definitive listed in Appendix and A, descriptive items documents 17. for the Propulsion Subsystem are 14 thru 43 PP',ECEDING PAGE E_L,_._'NK NOT FILh_ED. Vl. ELECTRICAL POWER SUBSYSTEM Electrical tion can silver be power is supplied respect Three by by a solar sun dc by cell array command, (solar and panel) a sealed whose primary dc posi- oriented main bus with to the Z9-volt the zinc battery. are provided regulated power buses and a ZZ-volt to the unregulated Figure A decoder actuated. control ments command 6-1 electrical subsystem spacecraft. is a block diagram bus of the power is provided in the event bus subsystem. so that power to the central circuit for the command is flight Z9-volt will "essential" not be interrupted that the overload trip bus The Z9-volt flight control The Z9-volt power. overload. provides bus may a separate satisfies be disabled electronics. for Z9-volt in the nonessential This bus all other requireor by regulated event of an automatically The regulated units ZZ-volt power bus such provides as own unregulated solenoids, power and to those actuators, circuits and not requiring switches, regulation. to electronic providing their SOLAR PANEL The solar panel assembl_, array approximately via installed of 79Z at the top of the mast, arranged The consists on of a series/parallel-connected honeycomb periodically the sun and substrate adjusted, will The The remain solar panel solar cell modules feet in area. a planar be of a few the 9 square panel can commands, to compensate to the source incident for the apparent solar radiation motion within and perpendicular is the prime degrees. lunar day. panel of power a minimum during of 81 transit watts. is capable of providing BATTERY A 14-cell A, of the series-connected, provides when energy silver-zinc storage rechargeable spacecraft. watt-hours output voltage battery, The located in compartment capacity for the is3375 The minimum rate battery (see fully charged B, item 26). at a discharge of the 14-cell of 0. 5 ampere Appendix 45 IBATTIrRy C HARG£ COMMANDS MECHANISMS AU X I L IARY ENGINEERING _ SWITCHED SWITCHED CONSTANT CURRENT ?gv Z?v PULSES SOLAR 1 J REGUL ATOR PANEL 11 I [ OCR I BYPASS !! I J I I J J BOOST REGULATOR VOLTAGE BOOST PREREGULATOR _. SENS=NG VOLTAG E 9._ am_ AND _9 o_t 20 m, h UNREGULATED BUS 4"4,0 V 22.0 -4,SV t COMMAND (N&Q(.E/O¢SAOLE PRESSURE SENSING ANO CMARGE LOG,C ___ _OLTAOE"O I I I I I I I I I kJS _ESSURE AND VOLTAGE MAIN BATTERY VOLTAGE DROPPING CIRCUIT OVER LOAD TRIP CIRCUIT CURRENT SENSING TRIP CIRCUIT zg v NO_I_Ii|NTIkL BUS L_ COMMANO REGULATOR ON/OFF ByPASS ON NON EIIEN_AL BUS OFF REGULATOR CONTROL SENSING vOLTAGE TRIP I t_ LOW INPUT vOLTAGE SENSING TRIP cIRCUIT CIRCUIT I I I I COMMAND ON/OFF I I_ nV FLIGHT BUS CONTROL I RE MOT1[ VOLTAGE SENSI_ I CONTROL REGULATOR l FIGURE 6-1. ELECTRICAL POWER SUBSYSTEM BLOCK DIAGRAM 46 battery battery mental load. loads as measured on the will be load side of the mating -4.5) volts from electrical connector and no of the environload to full receptacle conditions, The and battery is charged 22 (+4.0, for all operating 40 ° to 125 ° F peak loads from and including is intended by the temperature primarily panel. to handle lunar night solar BATTERY CHARGE REGULATOR UNIT The rated the The battery basic output charge charge bus regulator unit, charging located logic in compartment and voltage A, is incorpoto enable in the to provide of the conversion varying battery logic voltage solar panel to be the used to charge charge allA/SPP is to couple the battery. regulator, stepping the solar battery motors. panel regulator and power unit contains switching optimum for charge The circuit, of the with from circuits function battery power solar optimum maximum the solar charge power panel regulator transfer. at varying circuit The to the accepts mum optimum charge regulator to maxiat the battery be con- voltages corresponding to the battery regulator can panel power The output. operation from earth. logic It delivers this power charge terminal trolled by The functions a. voltage. commands battery necessary Provide pressure 27 volts). of the optimum charge to: circuit provides sensing, logic, and control of automatic reaches charging 65 ±3 psi of the battery the until the battery battery voltage manifold is below (provided b. Automatically pressure drops restore below battery charging when the battery manifold 60 ±5 psi. power for charging until the battery and reaches a tapered 27. 3 c. Accept volts. charge all available At this point, from the battery charging is potential-limited impedance. results battery which d. Respond charging to earth functions. damage control commands override all automatic battery e. Prevent power to the charging event logic of an or open to any or other component battery. in the unit in the shorted 47 BOOST REGULATOR UNIT The boost regulator power. unit accepts unregulated power and delivers regulated The boost regulator receives an input voltage of 17.0___._jtoZ volts dc and 7. 3 provides 29.0 _i percent volts to the regulated output. This voltage specification is met only at the terminals of the regulator. The voltage available at a unit connector is less than this value by the line drop through the connecting wiring plus an additional switch drop of up to 0.5 volt, when transistor switching is required. The fied maximum regulated The overload current voltage. trip for circuit, the boost loads. the located in the boost and regulator unit, provides to all to drop drop to output of the boost regulator is 7.0 amperes at the speci- overload protection regulator an undervoltage causes the protection output nonessential to 27.75 zero and ±0.25 regulated volts, When overload voltage will voltage for to the nonessential I000 milliseconds. on at the regulated This to turn loads period remain load at 0 volts switches 20 to allows the individual If an in all equipment after for the Z0 time off automatically. recovered, the overload will is still present again drop to zero overload ms, trip and circuit so on has voltage When to i000 in a cyclic ±0.25 the volts, manner. the output the battery trip same potential will The drops remove below approximately loads 17.00 from overload in this by earth circuit manner. all nonessential of the overload regulated can be operation trip circuit controlled commands. and A, descriptive items documents Z3. for the electrical power subsystem are Definitive listed in Appendix 18 thru 48 VII. TELECOMMUNICATIONS SUBSYSTEM INTRODU The which and CTION telecommunications command A subsystem and consists decoding, provides of three and interconnected signal and groups provide transmission. reception data telemetry processing reception. commands. A link group provides provides circuits r-f transmission logic circuits analog command A signal sub decoding processing carrier group group decoding for all earth to digital analog, commutation, for processing conversion, digital and and video modulation of most data channels. DATA LINK GROUP The two data link group comprises and two a high transmitters, gain planar two array receivers antenna. two-way (figure A trans- 7-i), omnidirectional mode antennas, during ponder is employed The the transit phase to permit doppler The shift measurements. spacecraft-to-earth mode) The and total earth-to-spacecraft link is operated PCM-FM-PM, bandwidth of the link is a PCM-FM-PM PCM-FM-PM or system direct during FM transit system. (transponder operation. of system command oper- PCM-FM-FM, information There These are during lunar is dependent that can be on the mode selected by operation. from ating earth. four modes and as of operation their usable modes, are information bandwidths while at lunar a. Mode distance, A-High follows: antenna bandwidth antenna bandwidth with transmitter kcps. in low-power mode; in high-power mode; gain nominal b. Mode nominal c. Mode mode; d. Mode mode; C- information B -- High gain is ZZ0 with transmitter information is Z kcps. with transmitter cps. in low-power in high-power Omnidirectional information antenna bandwidth antenna bandwidth nominal D- is 1000 with Omnidirectional information transmitter nominal is i0 cps. 49 1 FIGURE 7- 1. COMMAND RECEIVER AND TRANSMITTER F i g u r e 7 - 2 is a block d i a g r a m of the telecommunications s u b s y s t e m T r a n s m i t t e r R e c e i v e r , and T r a n s p o n d e r Interconnections. Design redundancy i s employed in dual t r a n s m i t t i n g and receiving s y s t e m s (with the exception of omni antenna coverage redundancy) t o e n s u r e r e c e p t i o n of c o m m a n d s f r o m e a r t h and e n s u r e t h a t the d e s i r e d data w i l l b e t r a n s m i t t e d b a c k to earth. Two identical t r a n s m i t t e r s , located in c o m p a r t m e n t A , a r e provided; e a c h t r a n s m i t t e r i n c o r p o r a t e s switching t o p r o v i d e e i t h e r a high- o r low-power output. T h i s is accomplished by switching a traveling-wave tube ( T W T ) amplifier i n t o , o r out o f , the c i r c u i t . Both t r a n s m i t t e r s i n c o r p o r a t e p r o v i s i o n s f o r f r e q u e n c y moduE a c h t r a n s m i t t e r c o n s u m e s about 70 w a t t s in highTransmitter performance lation and phase modulation. p a r a m e t e r s a r e a s follows: Nominal output frequency = 2 2 9 5 m c ( S e e Appendix B , Item 1 3 ) Nominal output power = 4 0 dbm ( 1 0 w a t t s ) i n high-power m o d e power m o d e and about 7 watts in t h e low-power m o d e . ( S e e Appendix B , I t e m 14) 50 ANTENNA A OMNIDIRECTIONAL RF SWIT_,_ 0"--" DIPLEXER t--_ m_c 5 _ LOW PASS FILTERH RECEIVER A ANTENNA B OMNIDIRECTIONAL r TRANSPONDERJ A TRANSPONDER J HIGH GAIN PLANAR E_NA 2295 mc LTRANSM'TTER : B I T 2295 mc TRANSMITTER _ l A i_ ,L I I I I 3-/-/ 6 COMMAND" CENTRAL DER COMMAND OECOI_E R A SUBSYSTEM DECODER NO. I I o ,¢ m t o i_ I I I _ NO. NO.I 2 [ CENTRAL COMMAND DECODER B SUBSYSTEM DECODER NO. 2 NO. 32 SUBSYSTEM DECODERS I ASSIGNMENT BASIC BUS IsTHROUGH 7 J TV 8,10 THROUGH 291 ADDED AS NECESSARY SUBCARRIER OSCILLATOR ,SPA 1 L_ DECODER SUBSYSTEM NO. 29 3.9 kcps _, I I 17.2 bp$ "_ ATTENUATOR H 560 cp$ I SCIENTIFIC SCO'S PAYLOAD AND CHANNELS DATA ENGINEERING COMMUTATORS SIGNAL MODE I-MIDCOURSE MANEUVER tO0 WORD FRAME MODE 2-RETRO DESCENT I00 MODE 50 WORD FR_tME 3-VERNIER DESCENT WORD FRAME TRANSIT PROCESSING MECHANISMS PROPULSION ELECTRICAL RADAR FLIGHT CONTROL APPROACH TV POWER LINK ESP 137.5 960 cp$ bp$ csp ] l 39 kcps I 550 bp$ ANALOG TO 1_,-! = I DATA , I D,GITAL I=, T l i--1%°u° l I L MODE 4-MISCELLANEOUS AND LUNAR OPERATION I00 WORD FRAtME "L35 kcps t I100 bps SCIENTIFIC PAYLOAD LMODE 4) 33 kcps t 4400 bpl , TELEVISION AUXILIARY AMPLIFIER VIDEO B l FRAME TELEVISION COMMUTATOR v V_DE0 VIDEO i_ i_ CAMERA 2 CAMERA 3 VIDEO APPROACH TELEVISION CAMERA ID .._ .SURVEY TELEVISION CAMEFtAS I I I PHASE AND FREQUENCY SUMMING AMPLIFIERS 'hl- I SCO _ l a SCATTERING ( SUBCARRIER OSCILLATOR .A % COMMAND ENABLE/REJECT I ¢1DETECTOR l SCO :t1:2 - SCATTERING i SCO 7.35 KC ' r 2.3 kcps If l l l J 5.4 kcps _ GYRO SPEEDS I 52.5 L kcps ACCELEROMETER NO. I, LEG NO. I, V8 SEISMOMETER 2.3 KC ' VIDEO A _MPLIFIER ] -t I t AMPLIFIER PRESUMMING It_ 90 o,c0, kcps IlOkcps _'-_ ACCELEROMETER NO.2,LEG NO.2, V9 / J SCO SURFACE SAMPLER ELEVATION 200 KC I IkCCELEROMETER NO.3,LEG NO.3, VIO SURFACE SAMPLER ACCELEROMETER DATA ACCELEROMETER qp_ NO.4, F/C SENSOR GROUP, Vii t -_.,_ __ FIGURE 7-2. TELECOMMUNICATIONS SUBSYSTEM BLOCK DIAGRAM _-/-7_ 5Z Nominal Two of the Appendix are when signal output power = Z0 dbm (0. 1 watt) located in low-power in compartment is 2115 mode A, mc are (see type and mode, received of the two a part identical receiver/transponders, Their These and nominal signal are command B, Item link. 18). input frequency receivers of the double-conversion During the transponder with frequency enabled and modulated by command, crystal-controlled. one of the for an receivers accompanying function. is phase-locked transmitter. Each receiver thus the provides can perform excitation Either receivers connected redundant signal about this transponder is permanently two the received require to one transmitter for transponder the omnis operation, are intact. Together for lunar providing transponders provided at a ratio In this mode the is retransmitted 2.82 Three watts of Z40 to 221. power are receivers continuous unregulated antennas for command operation. on the spacecraft. Two telecommunications antennas array provided are and power omnidirectional the third for reception capable and transponder sufficient switching two operation, effective function is is a planar antenna of radiating An antenna of the antenna The real-time use television transmission. antennas. boom. to receiver included antennas nected switched to allow is mounted to receiver to use of alternate on an Each One B. omnidirectional conbe of the extendable other is permanently can Each A either and the the transmitters antenna. omnidirectional consists or the high-gain omnidirectional a turnstile Gain antennas cone, of a turnstile following than see half-wavelength characteristics: (composite B, Item dipole exciting slotted with the nominal -I0 db Greater antennas, pattern, 17) both Appendix Polarization Impedance Frequency The high-gain array Gain 3-db beamwidth antenna, with the Right-hand 50 ohms circular S-band installed following with the solar panel on top of the mast, is a planar characteristics: Approximately 8.0 degrees 27 db E-plane, circular (see 6.5 Appendix degrees B, Item 16) H-plane Polarization Right-hand 53 Impedance Frequency 50 ohms S-band using surface coatings to Thermal control of the antennas is passive, maintain temperatures COMMAND The from mand, provides process mands handle the DECODING command spacecraft each within acceptable limits. GROUP decoding receivers, command group accepts earth-transmitted sync and timing and command signals from messages each comand can comto generates for correct the control checks output direct (which a total address addressed on-off command complements, The and system signals commands control of 3Z4 to command (which time-interval sybsystems. operations) The quantitative is mechanized with operations). and spacecraft commands direct commands quantitative a resolu- tion of one The ment one part in 10Z4. decoding decoding selector, five subsystem unit, located The identical in compartment command central B, is the basic unit consists decoders 7-3 for the and in the digital One comeleof command command of the group. two decoding command Figure command receiver-decoder and redundancy, relationship subsystem form words or more mand of two are command decoders. central illustrates decoders, of the receiver-decoder command types decoders. The selector, command serial type and used link transmits binary digital information The of standard-length command are words. command with of the direct commands the quantitative type. direct always function in conjunction flight control a quantitative that to select the appropriate time may be in the subsystem requires a selectable words during interval operation. at all times command maintains link when no commands frequent bit sync, are use. but does being The not Fill-in transmitted, fill-in word select transmitted when the which periods requires and is a direct command word a subsystem Complement decoder. checks are made on the address (and reject bits and their complements, on command and bits. similarly, Failure The in the case of direct generates bits of the are commands a message quantitative fill-in words), signal that are to "check" magnitude these is telemetered not complement execution. to earth. checked; commands however, telemetered to earth for verificationbefore 54 < o 0 0 _=_ 0 L) < _4 I t-- I I 55 A receivers command decoder the four receivers output command receiver central rupted receiver-decoder and one selector central is provided command earth. to select decoders Two each one for of the two use spacecraft of the two transmitted form in processing receiverto one of Both the messages selector from flip-flops state in the a four-state of two be counter, and One to be signal corresponding command signal combinations will always receivers two central decoders. will permit central operating. receiver other select receiver processed will select of the corresponding The in the the operating corresponding The decoder. output command for a period inhibit at the input of the central remains 500 off. command Whenever decoder. command the nonselected is interselector of receiver comof the decoder modulation exceeding milliseconds, of the four receiver-decoder combinations automatically and decoder. switches Thus, to another if the receiver possible a new in use To fails, avoid receiver-decoder switching be bination desired therefore, to be will be automatically between selected. commands, which normal decoder entire unintentional must always command, combination modulation is a dummy present; a fill-in word, between command in essence command (figure command messages. incoming delivered is required transmitted The central the transmissions. 7-4), which synchronizes subsystem, and and provides timing are the controls major operation of the decoding processing are of the derived command from the and Synchronization messages. Control information generated decoders signals command in a timed to control types sequence their to all subsystem operation. words an interlock are provided - a direct Each command, which address, command, command complement time durations a Three quantitative consists and sync of command and command, address, command. direct command controls an The of an address The complement, command, an information. quantitative also no of operations and which sync in flight control, but has an contains address complement, command, inadvertent comple- information, precede of such command or complement. critical command, of an sync the interlock the must irreversible It also prevents address execution ment, commands. command command complements. consists and compares address, information. address and command, The central complement, decoder command bits to rejection their and respective initiation Failure reject signal to check transmitted results via in message telemetry of a message to earth. If 56 FIGURE 7-4. I CENTRAL COMMAND DECODER both a d d r e s s and command complement checks a r e s u c c e s s f u l , a command enable s i g n a l i s generated and t r a n s m i t t e d t o e a r t h . T h e a d d r e s s and command information b i t s a r e delivered t o a l l s u b s y s t e m d e c o d e r s w h e r e they a r e decoded under the c o n t r o l of the a d d r e s s enable s i g n a l and the c o m m a n d enable signal, both of which a r e generated i n the c e n t r a l c o m mand decoder. The a d d r e s s that is assigned to all quantitative c o m m a n d s i s decoded i n the c e n t r a l command decoder. T h e function of a s u b s y s t e m command decoder i s t o supply actuating o r c o m m a n d signals to chosen locations by deciphering the digital information supplied b y the c e n t r a l command decoder under the control of the c e n t r a l c o m m a n d decoder. Subsystem decoders a r e available with t h r e e s i z e s of 57 matrices so that 8 {3 modules), Z0 (4 modules), or 32 (5 modules) possible command outputs are available. The maximum number of subsystem command decoders that may be addressed is 29. At scientific The a. b. c. d. e. f. g. h. i. j. k. 1. present, payload twelve Data Signal the basic uses are 5. assigned as follows: approach camera (No. 4). bus uses 7 subsystem command decoders and the link and television processing. power. mechanisms. mechanisms auxiliary. Electrical Vehicle and Engineering Flight Control. survey survey camera camera {No. {No. sampler. 2). 3). Television Television Soil mechanics Alpha Particle surface Scattering detector. Micrometeorite Seismometer interface to a matrix subsystem Command simultaneously the selected signals and from OR the central command to the signal decoder same OR are gate fed of central to an gate. Also, enable decoder, When the address are is fed from is fed out the command gate decoder. all signals flip-flops present, redundancy). checks a set pulse If the are turns both on of the to a pair address enable selected of parallel and (for central command a comamplifier of the of decoder mand of the command the matrix command will be complement generated. This successful, the power The states signal signal subsystem signals to go decoder, energizing determine its matrix. which interface is allowed at this time high. command output 58 SIGNAL PROCESSING GROUP The signal processing group gathers the engineering and verification signals from various subsystems and provides the appropriate signal conditioning. The signal processing subsystem comprises the engineering signal processor, central signal processor, auxiliary. The data being the from engineering the Surveyor low data rate auxiliary, and signal processing signal processor, and located puts on compartment form B, processes to spacecraft This bus it in a suitable handles data). preparatory transmitted to earth. of the basic signal processor (engineering all data required to assess performance The engineering four processor two current and is composed sources four of the following (thermal major comone ponents: command The modes plus two commutators, and reject signal measurements), channels. capable of 9._8 words of enable channel_ processor accelerometer a commutator 4 consist engineering contains of four of data 48 words of operation. sync plus words Z sync of data the Commutator (a total of i00 words plus modes words). i, Z, and Commutator Each 7-1 word 3 consists consists a sample The of data bits, format on the (a total of 50 words). one parity bit. Table of iI digital frame positions the I0 bits with frame I00 The contains first four words of the frame and sync) are illustrated. also first two To (sync words sampling primarily complement of the message formats by explained. the scope and illustrate entire frame is beyond modes of this document. 3 have been critical and correction, of commutator i, Z. for the established periods commutator mode mode other Z; and 3. telemetry requirements descent: using following during transit or terminal midcourse high gain maneuver antenna, mode i; terminal descent format descent using commutator commutator established by all terminal sampling omnidirectional mode antennas, 4 has been The of commutator excluding can offivebit be those telemetry Each requirements commutators at any The one previously at any 17.2, by the listed. time by 550, command II00, or (but of these operated rates: only 4400 one bits at a time) per 137.5, second. located only by bit rate is controlled signal operating analog-toof the bit rate of digital rate each converter in the bandwidth central processor. time. 7-2. Selection The is limited commutator available is listed at a given in table frame for each bit rate 59 TABLE 7-1. PORTION OF ESP COMMUTATOR DATA FRAME Word No. Mode No. Signal Commutated O0 1 2 3 4 Sync Sync Sync Sync Sync Sync Sync Sync Complement Complement Complement Complement 0 Primary on mode Doppler word 3 Doppler words 4 1 2 Omni Vernier 51) Sun Sensor Pitch Zl, 41, Error 61 and (also 81) on occurs I, words Velocity V x (also occurs mode 2 of Velocity 21, No. 31 and V X (also occurs on mode 3 of 41) A Power 1 Transmitted lines No. 2 Temp Doppler word 52) Velocity Vy (also occurs on mode 2 of Doppler Velocity Vy (also words 22, 32 and 42) 4 Transmitter Primary on mode Sun A Temperature Yaw 23, V occurs on mode 3 of Sensor Error 43, 63 occurs (also and 83) on occurs l of words Velocity Doppler word 53) Z (also mode 2 of 6O TABLE 7-1. PORTION OF ESP COMMUTATOR DATA FRAME (Cont) Word No. Mode No. Signal Commutated 3 (Cont) 3 Doppler words Velocity 23, Phase Z3, 33 and Error 43, V Z (also occurs on mode 3 of 43) A (also 83) ZZ, Star Pitch Manual Mode PrecesLockon Z3, occurs on mode 4 4 Static of words 4 Rate Cruise sion ZZ6, Mode 63 and Sun Mode Z01, Mode, Inertia ZI9, Switch, B05, Enable Nominal Signal Thrust and Temp Bias Doppler (also Zl8, Altimeter R-ADVS mode 4 Reliable 4 Main RORA, Reliable on Battery 42) occurs of word Sync complement is 0 0 0 1 1 1 sent 0 1 1 0 1 on (this is the the next barker code complement word that is read sync out and to earth commutator preceding to further establish commutator frame synchronization) Sync digits is 1 least l l 0 0 0 1 0 0 l 0 (this is a calculated the barker series code, of and likely start eleven to occur of each at random, commutator T301 start called frame. thru indicates states and the This and defines is read frame. the out of the digit times, the T311, sent to earth to indicate of a commutator There commutators; and one digital signals are two five different analog voltage are from types of inputs two available in the engineering types, types, temperature inputs A measurement type. which There vary one 89 high-level 0 to +5 volts. and available for processing inputs provide analog sampling number than of these one word on more The ±0.2 than basic commutator on more high-level This in a given inputs does will not be commutator. approximately include errors accuracy of these commutator however, percent of full scale. signal tolerance, such as, that exist in the sources, transducers, voltage 61 TABLE 7-Z. TIME REQUIRED FOR ONE FRAME OF COMMUTATED Time Required (Seconds) DATA Sampling Rate Bits per Second 17. Z 137.5 550 Ii00 4400 Commutator 1 Words per (100 words Second per frame) 1.5 12.5 50 i00 400 64 8 2 l 0.25 Commutator 2 (i00 words per frame) 64 8 2 l 0.25 Commutator 3 (50 words per frame) 3Z 4 1 0.5 0.125 Commutator 4 ( 100 words per frame) 64 8 1 0.25 dividers, processing applied output absolute scale when within inputs etc. There are ii low-level varying from with differential 0 to +i00 a nominal inputs available These The for inputs amplifier The of fullis ±i percent generated by system. these The drop are analog signals millivolts. gain of 50. to a differential is then processed amplifier as an ordinary processed 0 to +5-volt on data. by three Most of is such these The high-level is ±Z signal. percent accuracy the of the data use of the inputs without using the will calibration defined processor. measurements shunt absolute accuracy points processed control a calibration engineering consist value curve signal calibration of the data of current of each the power that the resistance never current expected voltage exceeds i00 millivolts. There ments. These are 64 inputs available are for processing obtained by basic temperature a constant as measurecurrent of of measurements to temperature but do not exceed supplying vary 5 milliamperes temperature measurements temperature There measurements. sensors 1000 which The in impedance accuracy a function of these ohms. on the expected is _:4° C, sensors. are seven These depending calibration accuracy of the particular inputs available for processing are obtained by high-accuracy supplying temperature measurements a constant 62 current of Z. 5 milliamperes to temperature sensors which vary: in impedance as a function of temperature but do not exceed 2-000 ohms. The expected accuracy of these measurements digital inputs is approximately handle certain of two Such _l. 0 ° C. quantities to be transmitted that consist The only device off. of an or indication electrical of which quantity. states a signal prevails regarding as being a mechanical either than open on or is defined If it is on, or is off, it is defined a voltage -3 as having between and ÷i a current +5 and +i0 of not greater volts (or an 3 microIf a milli- amperes, signal ampere. engineering being circuit}. 0.2 it is between are volts and words is capable of accepting available There a total of four digital (40 inputs) in the signal and processor. enable signals from the central _ngineering on when command signal needed decoder modulate This bandwidth frequency is present, equal the subis when it will to the a Reject 2. 3-kc carrier available. no enable subcarrier oscillator The or the oscillator will be in the processor. and when commanded oscillator is present. subcarrier signal will remain When the at its 2. 3-kc reject signal reject subcarrier enable deviate period signal for oscillator signal to a higher 21 frequency for a period When to a lower of the (approximately deviate the milliseconds}. oscillator signal enable is present, equal it will subcarrier reject frequency 21 milli- a period to the period of the (approximately seconds). The bines the central outputs signal from processor engineering are (figure 7-5), located in compartment and various basic or B, com- the signals signal processor sent bus phase- subsystems. modulation analog data These inputs and, processed The converting and to the has frequencythe data capacity for of the where transmitter. desirable, subsystem for handling it to digital digits, and subsequent signals The for con- transmission. trolling signal Synchronizing are contains summing r. patterns, generated two parity timing processor. three an commutators processor six in the central signal converters, central analog-to-digital power subcarrier oscillators, is olation The signals sive nished amplifiers, switches, and analog-to-digital amplifie analog-to-digital 10-digit binary converters numbers. voltage accept The with d-c analog signals by and convert these into converter increments With functions making succesfur- comparisons by a binary of the voltage analog of a reference comparison, voltage a logical weighter network. each 63 1 FIGURE 7 -5. CENTRAL SIGNAL PROCESSOR decision is m a d e , and the i n c r e m e n t of r e f e r e n c e voltage i s allowed t o r e m a i n o r i s s u b t r a c t e d out. This p r o c e s s continues until the e r r o r i n the b i n a r y r e p r e s e n T h e output of the c o m p a r a t o r w i l l These signals tation is l e s s than one p a r t i n 2 1 ° at full s c a l e . be the s e r i a l b i n a r y r e p r e s e n t a t i o n of the voltage being digitized. and sync w o r d s in a readout a m p l i f i e r . a r e s e n t t o the analog-to-digital timing circuit;-y t o b e combined with a p a r i t y b i t , T h e signal p r o c e s s i n g s u b s y s t e m contains two analog-to-digital f o r redundancy and output c i r c u i t r y c o m m o n t o both. converters E i t h e r analog- to-digital c o n v e r t e r will operate when it r e c e i v e s power on s i g n a l s f r o m the s u b s y s t e m T h e power on s i g n a l s f r o m the subsystem d e c o d e r s , available upon c o m m a n d f r o m e a r t h w i l l t u r n on e l e c t r o n i c conversion units i n the s e l e c t e d A / D c o n v e r t e r . T h e s e supply voltages d e c o d e r s and bias voltages f r o m the E S P c o m m u t a t o r ECU. 64 are applied to master switches which enable commutated analog signals to one converter and inhibit signal inputs to the converter that is off. Subcarrier oscillators are modulated by the outputs of the analog-to-digital converters. Five subcarrier oscillator frequencies are provided, each associated with a different rate of data transmission. Center frequencies of these subcarrier oscillators are shown in figure 7-?. Output signals from the analog-to-digital converter subcarrier oscillators are combined in the summing amplifiers and are sent to either of the two transmitters. The transmitters may then be either phase modulated or frequency modulated. This system uses individual "final" summing amplifiers to provide signals for the four different modes: (1) frequency modulate transmitter A, (2) frequency modulate transmitter B, (3) phase modulate transmitter phase modulate transmitter ]3. Two additional summing amplifiers to "pre-sum" number complexity through deviation output Centaur the outputs of various other sources. amplifiers The gain This and presumming thereby of inputs to the final for summing reduces A, and (4) are provided the circuit reduces the channel frequency required summing amplification. is such gate of each individual transmitter circuitry A series that the which desired is produced. provides This gate isolation provides is located a path data at the of the data analog-to-digital link subsystem converters. for transmission to the of engineering before separation. The transmission converters. dividing These carrier iary for The onmi the low low data rate auxiliary, located in compartment clock rates B, provides for data at lower Data rates bit rates than the lowest 137 pulse 1/2 from of the are analog-to-digital obtained processor. Two rate subauxilby of 17 3/16 and bits per the second 550-bit-per-second are available and clock central upon signal bit rates to all commutators 960 cps, are provided command. low data oscillators, use with the at 560 low in the data are rates. used primarily with the low-power must transmitter be limited to and low data rates directional adequate signal antenna, operating processing when the information bandwidth maintain The kc margins. auxiliary located the the in compartment r-f carrier ratio A, provides a 3.9- subcarrier oscillator which By modulates increasing at a phase modulation power index of 0. 3 radianpeak. of carrier to sideband 65 I the low DSIF, mode modulation while at the index same enhances time the probability the of carrier acquisition by data. the This permitting off when processor index. reception of engineering index of operation time the is commanded central signal a higher can Power modulation a is desired, at which oscillator iary provide for the bus. similar subcarrier auxil- at a higher from and modulation the Z9-volt signal processing is obtained Definitive nonessential documents Z4 thru 34. descriptive A items for the telecommunications subsystem are listed in Appendix 66 VIII. FLIGHT CONTROL SUBSYSTEM The during from down flight control phase of the subsystem of the controls the spacecraft This velocity covers and attitude period touch- the transit separation on the lunar include: Surveyor from basic mission. the Centaur phase the spacecraft The vehicle to spacecraft by the during radio for surface. functions and performed orientation based descent on flight control the entire data, subsystem transit and (I) attitude stabilization phase, (2) midcourse phase upright retro trajectory maneuver on correction and vernier command (3) terminal in an landing of the forms control-of spacecraft reference-are used. position the lunar surface. and Three descent principal radar subsystem. celestial Figure 8-1 reference, is a block inertial diagram reference, of the flight control FLIGHT CONTROL SENSOR GROUP The sensors frame flight and control sensor control group is made The up of a group of optical is mounted and on inertial space- the flight legs electronics. the hinge assembly of leg a three 3. the between The 1 and reference 3 near unit point inertial (IRU) the provides spacecraft axis rotational The gyros unit with reference consists associated Each spaceSpacecraft at a of and three an acceleration orthogonally control reference mounted, circuitry with a 'along strapped and single rotation roll axis. rate down integrating force balance temperature IRG craft comprises rotation with rate pulses gyro a linear degree angle. accelerometer. which B, integrates item 9.) a gyro rate of freedom, (See Appendix by to obtain rotation precise control to track during mits respect for to inertial period reference of time. is obtained The flight "torquing" a gyro a precise control electronics the produce spacecraft causing precession. the gas The jet attitude accelerometer correction control system to rotate spacecraft descent measures and lunar acceleration and 26-volt trans- midcourse the information power velocity vector phases to the flight control the gyro motors. electronics. The gyro Three-phase signal 400-cycle operates generators, 67 I I I 0 _J 0 ,-1 1 '' IIII .,.I 8 ,-1 0 I I 0 c_ I I 0 I.--I S I I ..4 I O0 kl I I _IZ 1' w _ I I H I I I I 68 temperature 2Z-volt controllers, 29-volt dc andaccelerometer power, respectively. utilize Gyro single-phase motor speed 10-volt signals 400-cycle, are dc, and telemetered to earth. Temperature restricted Internal range gyro of the three in the vicinity gyros must be maintained within a closely of 180 ° F and for all spacecraft circuitry the and flight attitudes. heaters are employed perthe gyros the temperature the specified inertial sensing control To to maintain turbations, rest and of the temperatures. reference However, are reduce effect of all external from heat, the has the unit is largely to dissipate to the IRU thermally decoupled generated The spacecraft. circuitry internally radiator. heat and within of the sun associated coupled radiator capability unit, sun of radiating the gyro the total internal as well electrical as direct dissipation reflected the unit. spacecraft sensor also of the IRU energy from the excluding and heaters, spacecraft primary to maintain sun line sensor during a thermal detects coast balance deviation The the roll axis supplies sun from a signal sensor sun-spacecraft the Canopus The phases. when the The sun to open field sensor primary shutter sun falls within of one lockon a defined and four of view. sensor consists The directional for to cadmium-sulphide transfer of control sun photoconductive of the spacecraft The cells. lockon from the cell provides secondary signals to within sun a signal sensor attitude the primary control degree sensor. directional the spacecraft cells supply enabling less than the flight 0.Z +0.3 subsystem limit Thermal cycle to control deadband, roll axis of the spacecraft-sun results base from and the line. combined outer the effect case support of (a) conductreatand the control the case of this unit and the tion between ment, primary the the which sun support (b) the between surface base minimizes sensor temperature case. cells The gradients surface treatment to optimize of the heat inner cavities surrounding and photoconductive cells. The inertia throw is designed flow between the housing switch, switch, a spring-restrained at a nominal level mass 3.5 g that operates as retro-rocket decay a single thrust decays. pole This by single g level closes corresponds to a thrust on a constant signal end curve. at the Therefore, instant the made. timing a command-to-initiate switch opens) a safe retro-eject prediction of the (initiated inertia of retro-burning can be 69 The telemetering accelerometer during is an descent. engineering The instrumentation is a sensor spring that measures restrained, connected The This acceleration seismic mass 29 volts sensor accelerometer arm of a linear that drives dc. detects, a fixed with the pickoff potentiometer across Canopus identifies, spacecraft the primary and locks on to the star Canopus. Canopus sensor sensor function establishes In combination required roll attitude sun sensor, relative the The to the line of sight. establishes uses Canopus Canopus the celestial tube three-axis B, reference. item a photomultiplier (See Appendix in the 8-degree error II) with suitable elements of to (i) establish Canopus the star the presence, nominal field of view, to the angle star The systems power. The intensity Canopus of a star of the as an brightness; of view; (Z) provide and signals and related star aid on to roll field map-making (3) measure Canopus and telemeter for positive electrical 400-cycle identification. control dc sensor from contains 3-phase, to supply ment the internal 26-volt, mechanical and operating unit power Z9-volt control cycle are is designed Canopus align- information +0.3 degree enabling the flight limit case subsystem For so as to hold thermal to have as well to 0.2 external including of the sensor deadband. finished control, the as capability the direct surfaces of continuously and reflected The decoder, the radiating solar energy. the internal electrical dissipation flight and control electronics electrical that the consists conversion of control unit circuits, The are the programmerlocation not of this to of on the ac/dc is such irradiation finished as well circuits. surfaces The spacecraft solar are primary radiating transit subjected surfaces any direct in a normal to obtain as the attitude. external radiating the case solar capability of continuously during items reflected causing With level no energy, power control the unit period dissipated of other is capable coast within phase, the without perturbations additional to the thermal thermal control, spacecraft. phase of radiating the thrust of dissipation The control maneuver. flight control circuits for for a maximum of I0 minutes. guidance the signals and process or them for flight control circuits accept of propulsion The systems to achieve are The desired on five include circuits stability circuit controlled located in the control circuits unit. installed circuits (Z) logic boards mode signal electronics control mode (I) control for input switching processing; selection; 7O and (3) analog circuits system. for converting sensor outputs to commands for the propulsion The signals and power for flight initiating control and programmer controlling units for of the is a digital unit within that the provides flight the yes/no control programmer lockon output electronic s sequences spacecraft. control, provides and sun a timed generates maneuvers control from unit, the sensors, predetermined to generate sequence. serve buffering involving counter a dual between timed which time bus. the the management the signals Basically, lockon, and generates to the time certain main delays Most commands system classified switches, signals, flight the attitude star of according signals during variable correction. command retro-staging for of or decoder as the when the sequences; sequence; attitude to the sequence precision and midcourse output radio-command velocity are transmitted programmer Other radar, switch. enable outputs for inputs, the controlling inputs flight programmer flight respectively. altitude and marking the inertia sequences, specified control magnitude or special spacecraft they arrive the information central inputs, are separation in certain logic retro staging decoder from sub- legs-down These the input advanced control flight Seven programmer of latch and controlling operation output amplifiers interface purpose the delays provides delays. of providing mode and by of timing: power is flight a 10-bit memory control magnitude auto taken capability electronics. shift time the power voltages circuits, sun electronics, programmer are two performed types Operations register/scalar delays dc and flight auto external from The internal Electrical Z9-volt supply required inertial sensors. and control electrical for conversion operation unit, of the units flight develop control sensor, units the and control the d-c and control a-c programmer-decoder and are primary installed dc and and in ZZ-volt the flight dc reference The obtain electrical input Canopus conversion secondary control buses. power from Z9-volt SECONDARY The signals transit to and SUN secondary enable SENSOR sun gross sensor alignment of the solar effects of the the initial sun roll !unar detection axis operation. to and the supplies sunline The during spacecraft during positioning panel secondary 71 sun sensor, on cell. of the its axis an assembly the The solar solar axis panel of five cadmium-sulphide Four of the cells sun are photo-conductive directional is aligned cells with cells, and one is is a mounted lockon axis and panel. of the cells. secondary The solar sensor the principal position the view Centaur a panel is erected after to the transit from sensor aligned to the spacecraft roll axis cells of the separation sun vehicle. complete maneuver Signals maneuvers primary sun Since the four directional with each secondary quadrant, hemisphere, in any from the cell viewing the sun one a yaw or {pitch) more and cells. pitch of the when The which and operation. of to is the direction secondary the will bring sun sensor into view of one produce successive to within to the sun the yaw to orient sun sensor. spacecraft roll axis field of view sun lockon sensor cell. Control is transferred of the from electrical electronics for output primary primary is within sun the field of view sensor operates sensor secondary taken from from the approximately conversion conversion from 5 volts unit unit dc power, transit lunar the flight control signal diodes processing are during during Protective "other earth. provided The operating levels either source are in case telemetered source" failure. of all five cells Thermal conduction of the during case control the of this unit is obtained sensor case and the from support the combined effects surface -I00 of treatment between structure; between day. is expected and-125 to maintain and +235 °F the unit temperature during the lunar and +I60°F transit RADAR S The altitude-marking from flight. measuring of in flange, When 52 the to 60 the The lunar radar surface generates to initiate radar a single Appendix nozzle washers ignition to is input eject powered commands, and between begins, the the output B, is an the is "altitude terminal a mark" descent signal phase pulse-type can The by be p._r_eset for at a preset of the slant spacecraft range altitude-marking radar miles with {See single-package sSgnal that fixed-range slant radar the flange. develops The away ranges mounts nozzle item retained 20). altitude-marking clasps radar by the from through and ignitor the nozzle. a breaksignal, and around the retro-rocket spring friction with retro-rocket altitude-marking gas generated radar volts dc bus sufficient pressure radar also carries altitude-marking from the the Z2 altitude-marking plug that output altitude-mark 72 telemetry 9. 3 kmc. The point information. Figure thermal mission isolation 8-2 The altitude-marking diagram for radar operates at a frequency radar. only of is a block of the altitude-marking it operable mark control designed this unit makes the 60-mile to that Use of the in which of the it generates trigger signal. of thermal active altitude-marking survival phase and radar electronics, of the combined required with operating radar heating, ensures During transit the transit attainment mission, 20°F by temperature. components controlled are of the all altitude means marking maintained up to the at approximately time of required of thermostatically heaters operation. The range lunar down. separate and radar altimeter and doppler velocity of the from sensor (KADVS) with measures respect slant to the touchtwo orthogonal during three-axis the descent common velocity phase spacecraft surface retro-rocket and components burnout to near the RADVS functions, four utilizes altitude circuitry and to perform velocity mounted determination (I) an i hinge r-f point; three-axis (KPSM) determination. on the omni It comprises antenna beams velocity legs leg assemblies: near leg under beams signal I and section 1 structure I and (2) the altimeter/velocity between under legs 1 and antenna, 2; (3) the B between above the 4, mounted antenna, (4) the legs compartmentA 2 and data 3. 3, mounted sensing 3; and compartment on the I and 3 hinge, converter The antenna mounted spaceframe, contain between assemblies also ANTENNA MARK SIGNAL_ PROCESSOR ENABLE SIGNAL,,_-o v°°FlH H H H SYNCHRONIZER TRANSMITTER AMPLIFIER AGC VIDEO O ETECTO R MIXER CIRCULATOR LOCAL OSCILLATOR TR TUBE FIGURE 8-2. ALTITUDE MARKING RADAR BLOCK DIAGRAM 73 r e c e i v e r microwave components, c r y s t a l m i x e r , a n d p r e a m p l i f i e r f o r e a c h b e a m , a s i l l u s t r a t e d i n figure 8-3. The r - f section contains t h e two k l y s t r o n s a n d the a l t i m e t e r k l y s t r o n m o d u l a t o r . The a l t i m e t e r k l y s t r o n o p e r a t e s at a m e a n f r e quency of 12.9 kmc w h e r e a s t h e velocity k l y s t r o n o p e r a t e s a t 13.3 k m c . A waveguide connects the antenna a s s e m b l i e s to the r-f section. F i g u r e 8-4 i l l u s t r a t e s the o r i e n t a t i o n of the f o u r r a d a r b e a m s with r e s p e c t t o the s p a c e c r a f t coordinate s y s t e m . F i g u r e 8-5 i s a functional block d i a g r a m of t h e RADVS. R a d a r beam 4 i s p a r a l l e l to the s p a c e c r a f t Z a x i s a n d develops a l t i t u d e o r range information. B e a m s 1 , 2 , a n d 3 develop t h e t h r e e - a x i s velocity i n f o r m a t i o n with r e s p e c t to s p a c e c r a f t c o o r d i n a t e s . B e a m s 1, 2 , a n d 3 a r e o r i e n t e d about 2 5 d e g r e e s divergent to t h e s p a c e c r a f t t Z a x i s a n d p a s s through t h r e e c o r n e r s of a s q u a r e p a r a l l e l to t h e X - Y plane. Beams 1 a n d 2 f o r m a plane p a r a l l e l t o t h e X a x i s . B e a m s 2 a n d 3 f o r m a plane p a r a l l e l t o the Y a x i s . Slant r a n g e along the Z a x i s i s d e t e r m i n e d in beam 4, whose t r a n s m i t t e d r - f i s swept i n f r e q u e n c y . FIGURE 8-3. 74 RADVS ASSEMBLY WITH PREAMPLIFIER COVER REMOVED L KAD'q5 BEAM OF_IIsNTATIOIq _,_GUg._ 8,_. VELOCITY SENSOR ANTENNA [ -- -- -- SIGNAL DATA CONVERTER 3_ _ TRACKER DOPPLER NO 3 CONVERTER l ' v __ 'I" RF.L,IMILE OI_RATE PREAMPLIFIERS CRYSTAl. R|,IAIILE OOPI_LI[R vELOCITY S(NSOA I35 mc OCqERATI[ DOPP_(II III[LIAJL $(_SGm V(LOCITY Ir 00_ KATIE _ ( DI'03"D PROGRAMMER _ 4 ) _&OA_ tu0( Q(LtAELI[ ALtl O_ IIIATE ( Ol" 021 ÷101' O31 ÷1D2"D31 RADAR ALTITUD£ SENS_t 12.g IIme _ RE L IAll_.l[ OI_KATI[ DOn't. £ II VE_.OCIT Y CON0_TIONAt. S[_SGm J N0, I VI CONVERTER vI so mv/tDs :1 I RANGE _ IOOO FT. MARK _ 14 FT, t v NO. 4 RADAR ALTITUDE RELIABLE OPERAT F cO?:._,R/ ?.RAN,, VELOCITY SENSOR ANTENNA FIGURE 8-5. KADVS BLOCK DIAGRAM 76 A sample of the transmitted frequency, and their frequency difference in each extracted to the difference spacecraft beam by is mixed a crystal trip" with the received The beam energy detector. time and 4 difference to range are frequency the beam to the is proportionate 4 path. velocity The of the r-f "round therefore 3 along frequencies along their of beams respective I, Z, and beam proportional paths. Range the doppler along is determined frequency the by compensating to produce Velocity the beam an 4 difference signal by pair frequency corresponding for to shift errors Z axis. "audio" range sensed beams signal along spacecraft frequency is determined of each summing the doppler with data each shift of the Three reflections of constant-frequency solved in the velocity axial or divergent converter spacecraft velocity paths. simultaneous "audio" of summing each Y axes, equations are to produce axis. The a doppler method By corresponding determines of velocity to the whether beams, transverse I-3, 2-3, is computed. along the X, using pair i.e. I-2, the and B, velocity altitude item 21. Z, and and respectively, for RADVS are is determined. given in Velocity Appendix capabilities accuracies Thermal thermal completion from the capacity control of the RADVS acceptable operation. dc bus. is passive, temperatures Power relying from on surface the coating to and to ensure beginning of its required unregulated is supplied to theRADVS system 22-volt ROLL ACTUATOR The and an roll actuator position vernier the range consists transducer. engine of a two-phase This assembly induction provides by parallel motor, a gear train, angular during 1 over roll-control swiveling to both vernier the Z-axis signals 26-vrms Position 10-vrms moments engir_e and from 400-cps feedback 400-cps thrust phase operation of _+5_.5degrees engines in a plane 2 and to a line through the flight power control with vernier 3 in response motor phase to electrical operates from subsystem. phase fixed The and actuator the one control variable. from is provided power. by an induction potentiometer operating 77 ATTITUDE JETS The attitude jets supply the reaction forces for spacecraft orientation maneuvers during the period from Centaur-Surveyor separation through preretrorocket firing. The attitude jet system consists of a spherical tank containing approximately 4.5 pounds of nitrogen under high pressure; regulating, and dumping valves for gas supply control; and three pairs of opposed gas jets with solenoid operated valves for each jet. (See Appendix B, item 12.) The gas jet pairs are installed at the ends of the three landing legs shown in figure 3-2. Number one jet pair lies in the X-Y or horizontal plane for roll maneuvers. Jet pairs 2 and 3 are approximately parallel to the vertical or Z axis. Cumulative thrust produces pitch rotation, and differential thrust produces yaw rotation. Execution of specific maneuver commands is accomplished by actuation of the required solenoid valves to release nitrogen gas to the designated nozzles. The six solenoids are connected to solid-state switches in the flight control electronics. Each gas__jet supplies a thrust of approximately 0.057 pound at a radius of 70 inches from the center of gravity for angular acceleration. The moment capability of the attitude jet system about each axis is: Roll axis Pitch Yaw The measured The and its own axis axis of the nitrogen to earth. of this system is passive, the utilizing surface gas coatings supply and tank and +4.0 +4.25 +_7.0 the in-lb in-lb / in-lb 2 attitude jet are temperature for tele,netry thermal thermal within and number control capacity to maintain limits temperatures of the the jet valves Definitive listed acceptable descriptive items 35 throughout for the the mission. flight control subsystem are documents thru 44. in AppendixA, 78 IX. APPROACH TELEVISION SUBSYSTEM The over During the approach range from television i000 to 80 subsystem _+20 miles provides {slant pictures range) above up of the lunar the lunar to i00 earth. surface surface. the approach frames television camera interval will be covering this altitude range, individual The approach television approach television cables figure relation The craft and 9-1. taken in response is composed to commands of the from subsystem and downward-looking with the television The approach auxiliary television unit, together camera the appropriate in and 2-2. to the spaceA at all be its connectors. The physical is illustrated camera in figure relative by location items of the approach and structures field of view television is shown is fixed to other approach spacecraft television system lens than 300 over and camera coordinate camera greater is approximately which maximum 6.4 degrees will provide aperture The 6.4 degrees. pictures The fixed-focus altitudes preset view is employed feet at the the range in-focus of f:4. center iris may field of at the +0.5 before launch of f:4 to f:22. may be of the of the approach assembly block television to be diagram approach heater elements subsystem parallel manually Z adjusted axis within time degree. of spacecraft An in figure switch for to the spacecraft overall 9-2. of the approach camera blanket itself are television {designated subsystem TV camera is shown 4) and the Only the its electrical All and/or other unique are to the approach with the television survey television camera and subsystem. subsystem itself command point surface illustrated shared The only other spacecraft subsystems. requiring Upon the command camera signals Such approach television power is completely signals in the lunar for self-contained, operation. phase, primary earth electrical from at the appropriate images of the lunar approach will convert that include into complete and composite-video blanking signals. the all necessary received the from the synchronization central logic, command and control earth on and commands, off, initiate decoder the turn camera picture taking camera thermal power. 79 ,ELECTRICAL CONNECTOR VIDICON T B, UE iLECTRONICS Lfliwtna LCND ~UJJSTMENT FIGURE 9-1. SURVEYOR TELEVISION APPROACH CAMERA E l e c t r i c a l power f o r c a m e r a operation a n d f o r the a c t i v e t h e r m a l c o n t r o l i s delivered to the c a m e r a via the s p a c e c r a f t h a r n e s s f r o m the b a s i c bus c e n t r a l power control a n d distribution s y s t e m . T h i s e l e c t r i c a l power c o n s i s t s of t 2 9 vdc regulated voltage and t 2 2 vdc unregulated voltage. The composite s i n g l e - f r a m e video output f r o m the c a m e r a i s s e n t t o the t e l e v i s i o n auxiliary unit, p a s s e d through a s u m m i n g a m p l i f i e r , and then s e n t to the s p a c e c r a f t t r a n s m i t t e r . Two identical video outputs f r o m the c a m e r a a r e conducted through s e p a r a t e c a b l e s to individual s u m m i n g a m p l i f i e r s i n the TV a u x i l i a r y f r o m which the signals a r e f e d through individual c a b l e s to e a c h s p a c e c r a f t t r a n s m i t t e r channel. C a m e r a condition i s o b s e r v e d by analog s i g n a l s which T h e r e they a r e a r e sent f r o m the c a m e r a to t h e engineering s i g n a l p r o c e s s o r . 80 0 E_ 0 0 ! o_ I Z_ I--I 1 commutated in sequence mitter and with sent other picture to the central signal data processor to be digitized via the and combined transsent in engineering sequences. consist for transmission data outputs camera spacecraft camera, between Analog from the this manner, indication s. typically of temperature and operational status Closed-loop maintain camera permit before the thermal control of the camera within vidicon appropriate circuitry and faceplate operating have been is provided limits designed to during to temperature The of the vidicon camera and operation. initial warmup actual The camera associated electronics of the camera operation. television of the camera camera the camera vidicon faceplate approach provides is adjustable with 600 line-per-frame before launch slow to cover scan the as low as operation. range I00 from Sensitivity 800 to 3000 foot-lamberts, acceptable results at levels foot-lamberts. The approach camera is located and mounted on the spacecraft chart in a position and collimalaunch of the that will allow tion lens vehicle approach constraints. surface reaching sequence. Figure and timing that at the limited may be observation provided of JPL. of an the illuminated spacecraft calibration shroud within This of the Centaur testing and or any point option arrangement assessment the in-shroud within the allows limited prelaunch by lighting chart camera, with a resulting of either shutter focus the lunar Observation by a calibration is controlled the vidicon The camera that prevents light from in the to sunlight. faceplate also until it is opened protects the vidlcon at the appropriate from sequence direct shutter exposure by 9-3 illustrates of the the picture-taking camera that may are both be controlled upon and which upon command the logic from earth. to camera circuitry and initiated running Horizontal reduce vertical circuit and generators complexity. pulses, The free unsynchronized produce application the camera These generators, synchronizing power and run blanking start automatically nominal g00-millisecond for the the of camera pulses When camera a continuously. timing vertical blanking represent start video frame logic the principal command circuitry initiates a nominal waveform from The picture-taking command blanking triggers vidicon. sequence. decoder, pulse the is received is enabled. a picture-taking g0-millisecond central first vertical sequence exposure and to appear shutter thereafter to provide the camera of the 82 2OO rnsec-e_ 1 I"_j- I sec O) VERTICAL PULSES BLANKING ii II II rl n . I I I N+I b) "TAKE PICTURE" COMMAND !111 II II IJ' VERTICAL N [1 I I c) COMPOSITE OUTPUT VtDEO BLANK,NG AND/_'1 SYNC PULSES HOR,ZONTAL / I I '1 PICTURE READOUT HORIZONTAL I _ IIII [--AND SYNC I d) OPEN SHUTTER 20 rnsec I n II [I IJ I _"!,. e) FUNCTIONAL SEQUENCE 36 sec =-I _,'NcI SYNCl S,'NC SYNCI [ I II II I f) VIDICON CONTROL THERMAL INHIBIT SYNC J 'NHIB'T iI OFF OFF I ,NH,B,T FIGURE 9-3. APPROACH TELEVISION PICTURE-TAKING SEQUENCE The vertical permits blanking picture the first blanking data transmitted with display the during a picture-taking horizontal on earth to be sequence synchronizing synchronized before consists pulses. with receipt of the This pulse and with superimposed monitors receiving pulse video. and a vertical of horizontal picture synchronizing readout takes pulses place Single frame pulse. in the interval video start closes the following vertical blanking Transmission and The of the composite is terminated blanking and at the pulse resets information of the next the video requires (second) gate which approximately vertical feeds blanking video 1.2 seconds pulse. second to the television auxiliary shutter. 83 Three subsequent after the frame start periods frame are required must for proper not be vidicon erasure so that the until three command pulse received at the spacecraft permits third frames blanking to occur An of the start frame being sequence. This erasure (picture sequence command the readout the first one) is possible second take erase a picture in approximately in that scan and the camera 3.6 seconds. can receive being alternate frame of operation during the will a start the (picture respond erased. This picture readout normally. alternate every first), and the provide TV camera image In this case method seconds. defining can previous will not be completely capability for transmission of a degraded 2.4 The document for the television subsystem is listed in Appendix A as item 45. 84 X. SCIENTIFIC PAYLOAD INTRODUCTION The date various on basic design policies experiment weight, Z, involved subsystem center in providing the capability and to accommoimpli- payload spacecraft combinations and the detailed harness cations are craft of gravity, ll. This electrical defines design, space- described provisions in Sections for 3 and section the other and scientific experiment with emphasis subsystems on in detail describes and the experiments operation. An those themselves, electrical interfaces experiment by subsystem the basic bus, is defined which control, surface. are as all spacecraft necessary items, for other than provided uniquely the installation, of a scien- mounting, deployment, on the thermal lunar and functional an performance experiment tific experiment composed a. of the An Typically, subsystem is following items: sensor assembly or mechanism or a combination instrument two. of the b. Mounting perform provisions a secondary action. and/or deployment function or manipulative by initiating or mechanisms terminating to mechanical mechanical c. An and d. An as instrument operation instrument an electronics unit directly sensor. associated with the calibration of the instrument auxiliary to match unit to provide the electrical unit (if any) by the electrical interface and act "adapter" and requirements to the power, bus. of the instrument command and data sensor its electronics facilities cables transmission e. Electrical other provided the basic necessary elements. to provide interconnections between the subsystem 85 An "instrument" is defined as a sensor and its directly associated electronics. The electronics conversion unit and the instrument auxiliary are not considered a part of the instrument. The scientific instruments and accompanying electronics units and/or mechanisms required are either built by Hughes or furnished by JPL. The instrument auxiliaries are provided by Hughes. The design approach outlined in Section Z is implemented to provide basic bus subsystems that are, to the greatest extent possible, independent of instrument complement. The spacecraft basic bus provides only two power forms, unregulated ZZ vdc battery power, and regulated Z9 vdc power. The telemetry system is designed to accept only input signals in the range from 0 to 5 volts. The central command decoder is part of the basic bus, with provision for connection to subsystem command decoders for each instrument. The auxiliary unit for each experiment subsystem then provides the interface circuitry between the standardized basic bus subsystems and each individual instru- . ment as defined above. Each auxiliary unit contains a standard subsystem command decoder capable of supplying 8, 20, or 32 commands, as required. Power switches for turning the instrument on and off, for controlling heater power, and mode changes, etc., are located in these units. The instrument signal outputs are conditioned by the auxiliary unit as necessary to bring them into the proper voltage and impedance ranges. Subcarrier oscillators are also included in the auxiliary units. Special power supplies (ECU's) can be included where power form requirements are different from the basic bus supplies (none are necessary for the present scientific payload). Thus the basic bus subsystems do not have to be changed appreciably when the payload instrument complement is changed, and each experiment is largely independent of other experiments. The A-21A Surveyor Spacecraft carries the following five experiment payload subsystems: 1. Survey Television Experiment Subsystem - transmits pictures of selected portions of the lunar surface and other scientific instruments on command from earth and is composed of two survey cameras and the television auxiliary. Soil Mechanics - Surface Sampling Experiment Subsystem - investigates lunar surface properties and is composed of an instrument, and an instrument auxiliary unit. Alpha Scattering Experiment Subsystem - performs elemental analysis of lunar surface material and is composed ofasensor, an instrument Z. 3. 86 digital electronics mechanism. 4. unit, instrument auxiliary unit, and a deployment Micrometeorite Detector Experiment Subsystem - provides data of individual lunar ejecta and is composed of a sensor, an instrument electronics unit, and an instrument auxiliary unit. Seismometer Experiment Subsystem - measures physical disturbances of the moon and is composed of a sensor, an instrument electronics unit, and an instrument auxiliary. 5. The following descriptions of the individual experiment subsystems include detailed discussions of the functional elements incorporated in each auxiliary. SURVEY TELEVISION EXPERIMENT SUBSYSTEM The survey television experiment subsystem provides the capability of observing the lunar surface, portions of the spacecraft, and large sections of free space, on command from earth. This capability is provided through an experiment subsystem consisting of two cameras and a television auxiliary. Each of the cameras can be commanded to alter its angular field of view and to change the angular orientation of the center of the field of view with respect to the basic spacecraft coordinate system. Provisions are also made for inserting colored or polarizing filters into the camera optical system on command from earth. This arrangement permits colorimetric and polarimetric evaluation of individual television pictures. These features are augmented and made practical by the provisions for commanding the camera optical systems to alter focus distance and lens aperture to adjust for variation in object distance and light intensity. Provision is made to alter the lens opening (iris) either on direct command from earth or automatically, as desired. With both cameras viewing the same area, stereoscopic coverage may be obtained. The Survey Television Subsystem is also used to observe the operation of selected instruments carried by the spacecraft. A functional block diagram of the survey television subsystem is illustrated in figure i0-i. All of the items appearing on this diagram are shared with the approach television subsystem. The telecommunications subsystem is shared with other spacecraft subsystems. The survey television camera is illustrated in figure 10-Z. The location of the survey television camera on the spaceframe and its relation to other units is illustrated in the general arrangement drawing (figure Z-Z). 87 I .I u_ wl., p |- I < r_ o N U © m < Z © I---4 O Z N [ 1 •_ii I m Z © 'l! i o! N M M m W o I as" I S 88 I o_ _,,J Ow I I as= I l o" j 3;o Ow _d MIRROR HOOD / /DRIVE MIRROR TILT ASSEMBLY MIRROR ROTATION DRIVE M O T O R 1 IF=-.: FILTER WHEEL FILTER WHEEL/ ASSEMBLY FOCUS POTENTIOMETER I SHUTTER ASSEMBLY IRIS POTENTIOMETER 1 \ VIDICON TUBE /: ' 1~ / /VIDICON RADIATOR / / ELECTRONICS CONVERSION UNIT FIGURE 1 0 - 2 . S U R V E Y TELEVISION CAMERA 89 The to the The The sion CDC relationship and the DSS of the ground spacecraft survey television experiment subsystem in figure spacecraft. for transmis10-3. transmission provides modulates system is illustrated for the commands CDC, DSS in its command transmitter spacecraft. survey performs television operation, and commands the CDC processes to the The experiment operations, back amplifies subsystem and to the the receives transmits the video, DSS the commands camera, is located spacecraft from and at the and preby the DSS, command DSIF). pares the the desired confirmation Upon reception, information the DSS and DSS. signal (The from CDC. it for demodulation the signal decommutation in the and in the is sent After demodulation in the System. system signals for may CDC CDC, is sent and to discriminators processing information on 35 and mm decommutators CDC to the Television television Telemetry TV video System frame and to video identification recording display on film. Selected meter may telemetry be sys- monitored tem, by binary, decimal, analog displays the displays. be obtained In the shortly television after a permanent a Land Survey record camera of video readout using The to photograph camera video output of the television images within monitor. its field of synchronizacamera and is television composite blanking converts signals optical which view into complete vertical include horizontal the tion and completely received The pulses. requiring power by the In performing only this function, power and decoded decoder command self-contained, from the central electrical system are inputs commands auxiliary. distribution survey camera The and the television by commands in the via received television the command and active a subsystem coded All from +22 vdc earth decoder commands auxiliary. receiver thermal system as subsystem central of the receives decoder. power cen- for operation tral power lated control +29 vdc camera is supplied voltage and the distribution regulated unregu- voltage. The principal identical amplifier information gate. thermal, location signal output from the camera outputs is the are composite from signal-frame the cables. camera Frame amplifiers contains to to each all to video. the Two signal-frame of the from Frame and and TV video auxiliary the camera supplied summing unit through is received data individual by the the identification through optical, describe 9O an summing camera enabling identification angular from electronic, the relative position information necessary pertinent engineering characteristics 1 I I I FROM PCM DECOMMUTATOR I I FI 1 VERIFICATION DISPLAYS COMMAND DISPLAYS COMMAND PRINTER I I I I i I I I I I I I I I I I DSS GROUND TRANSMISSION SYSTEM KEYBOARD I' I i I I I I I I I i I I I i I I F CONTROL SWITCHES TAPE READER a LOGIC CIRCUITS -____ 8 REGISTER CONVERTER I I I ] I I i] S C O _ __ I I I I I I I I I I I TELETYPE TO SFOF DIPLEXER __QUISITION AID NTENNA EMERGENCY COMMAND I COMPUTER EDITING II II I AUXILIARY SWITCH ENTRY PROGRAMMER a LOGIC AUXILIARY CIRCUITS I I I I II TRACK I NG O_O_._ PHASE MODULATOR TRANSMITTER DIPLEXER NTENNA CDC COMMAND AND SYSTEM I I I I I I I I I I I I I I I I I I J I_ b_ M _ m m SIGNAL t PROCESSOR ENGINEERING I I I 53j I I I SIGNAL PROCESSOR ___ CENTRAL 45 [ I I 1 I I I I I ; ENAB.LE GATE I I I MASER ___ 2KC NBPF __ AMPLI FI ER ]'.F. SUMMING AMPLIFIERS 22V 8k 29V lOWER SURVEY CAMERA COMMUTATOR FOR FRAME 16 CHANNEL T.D. CONVERSION _._ UNIT ELECTRONIC II I = I I DIPLEXER PARAMP L_ VARIABLE i;BANDWIDTH ___ DETECTOR PHASE H AMP VIDEO I \ \ / / I I I SUBSYSTEM DECODER | ELECTRONIC HEATER BLANKET I L 179/180 SWITCH T V AUXILIARY I I I VCO I: t i, DETECTOR PHASE I F I I I CENTRAL COMMAND DECODER B ] I I I I • ClLLATOR I I I I I /i I I SURVEYOR SPACECRAFT RECEIVER 51 COMMAND RECEIVER 52 I I I SURVEY CAMERA SYSTEM I I ! DSS RECEIVER 1 FROMSIF D TIME CODE GENERATOR TIME CODE BUFFER I FREOUENCY I I OSCl LLOGRAPH I I P LOW I FREOUENCY OSCILLOGRAPH I o O ,¢ o_ O I I BYNARY DISPLAYS (5) I I DSIF TAPE RECORDER DISCRIMINATORS (10) PCM DE COMMUTATOR ANALOG METER DISPLAYS (16) I I I [TO DSIF TCM-TO-TTY I ENCODER F.M. CALl BRATOR DEMODULATOR !EPUT METER ___ DISPLAYS DECIMAL (16) I I I I PCM CDC TELEMETRY SYSTEM SIMULATOR I J I "r _ : TO CONVERTER FRAME I.D. I I I I I CDC TELEVISION SYSTEM RECORDE TV TEST SIGNAL GENERATOR R_ I./"s I I I o\ _[ VIDEO MONITOR _--_..--..._-TIME -- _ _. -.._]_ J 1 35 I I MM _ COMMAND REGISTER SYSTEM I I I I I CAMERA CAMERA LAND J i L__ FROM TIME DSIF CODE CODE BUFFER I GENERATOR DISPLAYS TIME I I I I I J FIGURE 10-3. SURVEY TV CAMERA/GROUND !INTERFACE, FUNCTIONAL BLOCK EQUIPMENT DIAGRAM q /'(_ of&. televised been scene. The frame identification TV signal and consists routed the of analog to the data that has signal serially commutated The central in the signal auxiliary central data processor. form. This as processor to the converts TV analog and to digital with compofrom of signal pulse is then coded returned data in the auxiliary amplifiers. summed The site video the summing composite thereafter The that vide can be summing total signal consisting amplifiers video (figure survey is sent to the frame transmitters in a sequence data information 10-4). television with identification following immediately camera is equipped its maximum nominal) with a variable focal length focal length lens commanded to set at either (6.4 x 6.4 degrees to provide focus position or to pro- a narrow-angle focal length viewing (25.4 lens capability x 25.4 at its nomito minimum nal) viewing cover lar position The 4 feet by wide-angle of the camera degrees capability. from distance The is also commandable views the range to be axis to infinity. means inside assembly indirectly the particuThe elevamotors in scene televised is mounted of a gimbaled of the azimuth to position with be mirror gimbal the mirror earth stepped assembly. axis. tion gimbal are provided Stepping in the mirror or elevation camera surface angularly The optical of approxi- either azimuth in accordance may commands. in increments The centerline mately of the field of view and 3 degrees in azimuth 5 degrees in elevation. mechanical 2-1/2 elevation motion motion degrees optical of the in of the mirror per path. mirror azimuth. around an step, A or itself in elevation exactly half the is in increments increment between rotation motion of approximately of the the camera angular one-to-one in azimuth This axis relationship and the exists mechanical corresponding azimuth of the camera field of view occurs very because corresponds centerline is provided small to angular of the through heaters rotation lens. nearly control parallel of the to the optical survey camera and camera Temperature thermal the trol radiator a passive located on for the vidicon within for the faceplate camera. electrical electronic is also The chassis provided In addition, to achieve closed-loop proper thermal camera TV on con- the vidicon is capable emergency be faceplate operation. normal survey camera TV may of operating mode. to the The in either camera a 600-1ine is turned mode mode normal intent in a or in a 200-1ine mode and then mode in the The pictures switched emergency if required. quality for of the latter signal is to permit not as the transmission wide as that normally of degraded required limited bandwidth television 93 ! -_J H'I .67 ms I I l I J (NORMAL VER11CAL BLANKING PULSE j MODE) (EMERO MODE) I 1-Ii--._ H [ I *1.5 V (BLACK) +0..5 V START 0 OF PICTURE SEQUENCE / I _i -O.S V. 4 -I .5 V .200 (I_IORMAL ms MODE) I I hi J 600 ml -2.5 V (WHITE) -(EMERGENCY MODE) FIGURE 10-4. SURVEY TELEVISION COMPOSITE VIDEO OUTPUT 94 transmission. increase high-gain receipt priate and ground the The probability or basic of the of objective successful powered in providing television transmitter television the this mode of transmission to earth when is to the transmission is not usable. antenna display high (Successful use of of approthe emergency compatible mode with pictures requires transmission equipment mode. survey ) camera of 150 narrow-band emergency The nominal opened This taking is equipped milliseconds. period of time with a focal plane shutter that provides of being command. for a exposure for an The on shutter is also capable earth exposure is about reflex indefinite mode The receipt of proper operating purposes. is not directly maximum exposure shutter sampled shutter light equivalent to a "bulb" time A picture- equivalent beyond exposure this interval. 1 second, splitter regardless is provided passed a f:22, by the until of continued in front the lens. beam of the If the driving in the camera light is intensity of light in the camera viewed by is to sample intense prevents At the total light input and the f:22 in the shutter the iris is from manual mode may camera, direct or in not sufficiently and removed. circuitry the will a result inhibited is opening the occur (2) in shutter as the excessive open of regardless changes: intensity. area of field the Light-intensity coverage of view, viewed or (3) by in of changes the the (1) of the angular illumination The control on receipt camera orientation of same the reflected sun matic function The are remain fixed fore, approach In the angle. iris scene camera is also override because employed the a change in the autoinhibit light-sensing Provision ,commands. arrangement is made circuitry. of ground to shutter horizontal generated synchronizing when off. between The the camera pulses is and turned the on vertical (power does blanking applied) not require pulses and a There- independently until timing they are permits normal of mode the it is turned television the and horizontal independent in circuit pulse a system and of design vertical each relationship both a oscillators. other. and the This power principal is TV design free-running significant the vertical sequence. and the that central saving blanking complexity represents required. timing received auxiliary (via waveform the command picture When command video after an sequence. logic start frame command from is enabled. start frame pulse the receivers decoder, pulse decoder) circuitry subsystem cal turn, blanking initiates camera appears picture The first vertiin the earth-initiated This blanking command, triggers a complete 95 camera to be shutter generated The first to provide to turn signal the vidicon exposure on. and, simultaneously, causes a signal transmitter during with transmitted pulse a typical superimposed ground picture-taking horizontal monitors picture 10-5a). in the sequence con- sists pulses. before place of the vertical This receipt blanking synchronizing to be synchronized takes waveform is intended picture to permit video. of the actual Single-frame (figure seconds readout in the interval following signal vertical requires blanking about (second) 1.2 Transmission normal pulse. signal pulse mode The to the to close the and sec- of the composite is terminated ond blanking video at the start of the next the video vertical provides acts as blanking a video an enable TV pulse resets closes gate which and transmitter, frame complete enable the camera input gate shutter, to the video identification identification sequences pulse. The summer in the are auxiliary. Several during command the of frame trailing information initiates transmitted edge of this pulse a transmitter-off sequence. erasure. at the sequence. erasure nominally (figure during normally. TV that terminates Three the subsequent the three third transmission frame periods frame for that particular are necessary must for picture-taking proper vidicon Therefore, until will per- start command pulse not be start received frame spacecraft This after mit vertical blanking of the complete erasure The 61.8 frames three seconds to receive to occur erasure in the (picture frames emergency readout require mode command respond the occurs 3. 6 seconds 10-5b). the second In this image will It is during the first frame). mode the and and in the normal possible erase case, not be for scan since spacecraft the TV a start frame a picture and camera erasure from to take has not the third yet occurred, Through previous completely the erased capability the vidicon. this specialized (imperfectly operating erased} sequence, picture is provided every 2.4 camera earth to transmit a degraded approximately The survey receipt seconds. is equipped commands optical with to occupy filter. a filter wheel one of four that may different be posi- television of proper use rotated tions, before on each time providing of camera filters, with as of a different It is therefore of clear, of lunar scenes possible, colored, through or assembly, desired, to select to enable combinations polarizing optical observation filters known characteristics. 96 _w -f 2 -_?w o_ z 1 j -- --I_ __ _ ]_; ,_ o g-. i ___E _- z _- 0 - o _-Zgr u_ 0 E oE o T _ < I wo._"_ _ i_ ) _ii _oooo°°._ ._- 0_ _w E_ o H O_ © u_ _> o __ _ E_ _> ! 0 0 -- z 0. O_ o. 0 9? SOIL MECHANICS-SURFACE The purpose of the SAMPLING EXPERIMENT sampling SUBSYSTEM experiment subsystem sur- soil mechanics-surface the mechanical is: face; (i) to qualitatively (2) to provide within determine characteristics and of the lunar surface means its area for lunar soil manipulation; The surface modulus (3) to map to be and elevations are: nature of operation. shear properties investigated surface of the material, strength, of elasticity contour. The lunar with soil mechanics-surface by digging, viewing) scraping, in a limited will measure above. sampling picking, area those near experiment and the contour Surveyor subsystem mapping will test the surface television (in conjunction The spacecraft. experiment the lunar subsystem soil properties parameters necessary to determine listed Experiment The an vide and Figure instrument, Subsystem soil Characteristics sampling auxiliary the unit, experiment electrical and the of the the subsystem cables instrument on the is necessary auxiliary spaceframe. composed to prounit, of mechanics-surface an instrument between bracketrynecessary is a functional block interconnections mounting 10-6 instrument to mount instrument experiment diagram subsystem. Instrument The device scoop attached electric fourth extension, provided tion is the forces forces to Description basic soil attached are mechanics-surface to mounted the on end of an sampler extension and arm elevation Potentiometers of positions the consists arm vertically assembly and is extension are instrument. of output the (0 scoop to 50 used (see of a figure hinged clamshell-shaped 10-7). base The which by is three A (scoop) and to arm the a horizontally The extension azimuth, door. positions closed spaceframe. that operates control the and the manipulated motions. to Limit door. g of and the measure motors motor the scoop azimuth elevation, indicate system, on the switches An 0 to scoop accelera2000 are open and measuring mounted pieking over over providing to force 0. 0.1 to a dual-range measure transducers 1 to 20.0 3.0 pounds pounds. vertical are g), instrument Two range range deceleration provided; and the other one during action. the the measures measures vertical retraction from of 98 T 2.2¥ EXTEND I EXTEN_ONDRIVE MOTOR RETURN EXTEND MECHANICS SURFACE SAMPLER AUXILIARY RETRACT r I SHUNT -i I ] l-II II MOTOR I RETURN SOIL MECHANICS 22vd¢ UNREGULATED SURFACE SAMPLER PRECISION POTENTIOMETERS EXTENSION MOTOR RETRACT T SMS_ EXTENSION POSITION Z r -- --I R7 I---- .1 __ -1 ROTATE RIGHT I _A_ L___J I I EXTENSION DRIVE I I TRANSMITTER I A I I I TRANSMITTER I El I I I AZIMUTH DRIVE MOTOR RETURN I RIGHT J L_ ROTATE LEFT AZIMUTH DRIVE MOTOR RETURN LEFT OPEN I I I I I MOTOR RETURN OPEN AZIMUTH MOTOR . _ _ SMS$ AZIMUTH CENTRAL POSITION SMSS RETRACTION CURRENT SIGNAL PROCESSOR J AMPLIFIER SUMMING SCOOP r_T_ -i CLOSE DRIVE I r _ I I RECEIVER A SCOOP DRIVE MOTOR RETURN CLOSE I L J ELEVATE ELEVATION ELEVATE SWITCH DRIVE MOTOR RETURN ELEVATE I I I I SCOOP MOTOR SMSS RETRACTION FORCE "1 't SMSS ELEVATION FORCE "1 I MODE 4 COMMUTATOR i_ I DIGITAL CONVERTER ANALOG-TO_ I 4400 bps SUBCARRIER 0SC IL LATOR I J CENTRAL COMMAND I DECODER (CCD) LOWER -'1 I CODED COMMANDS I I _J I20 COMMAND DISENGAGE CLUTCH SUBSYTEM COMMAND DECODER ELEVATION LOWER SWITCH DRIVE MOTOR RETURN LOWER I i I i 1 29v REGULATED SWITCHED ELEVATION I SUBCARRIER OSCILLATOR IlO0 bps SMSS ELEVATION MOTOR /_)_ POSITION ELEVATION _LUTO_ C) ' # • • Y SMSS ELEVATION CLUTCH RETURN 2 sec/O.I sec TIMER 550 bps 129v REGULATED I RETURN FINE MODE INHIBIT I RECEIVER B I l I / FINECOARSE ION tOFF ] O'SEN_#D._LOTC"_ ''1, I 1 4.85vecRETURN I II Ib 4.85 :t:O. 15V dc I v'- I L II L ;[SUBCARRER OSCI LLATOR _ t!l 29v REGULATED MOTOR OFF _ T T' SMSS SMSS SCOOP FULLY CLOSED OPEN LIMIT LIMIT SWITCH SWITCH SCOOP FULLY / ALL MOTORS OFF 1 I I FORCE SIGNAL PROCESSING ELEVATION FORCE SENSOR ENGINEERING SIGNAL PR._._9 CE____S S_._OO R__ LIMIT 'S TRAIN STRAIN MEASURING ON _ POWER SMSS STRAIN MEASURING SWITCH AMPLIFIER POWER SWITCHES POWER ON TO RADAR AND SQUIB RETURN POWER OFF ACCELERATION MEASURING ON POWER SWITCH ON/OFF 29v REGULATED SWITCHED LIMITING RESISTOR I t I ELEVATION FORCE SIGNAL RETRACTION PROCESSING _ AMPLIFIER ACCELEROMETER METER 1 SQUIB l I ENGINEERING MECHANISMS AUXILIARY "_ACC ACCELERATION MEASURING OFF • ACCELEROMETER ERATION MEASURING SWITCH _' Ir / t AMPLIFIER POWER T / Y I SMSS ELEVATION POSITION i SMSS SMSS ACCELEROMETER ACCELEROMETER AMPLIFIER AMPLIFIER LOW RANGE HIGH RANGE CURRENT CONSTANT SUPPLY _ AND LOGIC SWITCHING CIRCUITS COMMAND INTERLOCK L___ TO CCD SUBCARRIER ACCELEROMETER[_ OSCILLATOR RANGE SWITCH " SMSS SMSS ACCELERATION DATA OUTPUT SUBCARRIEROSCILLATOR RELEASE SMSS I SQUIB HIGH-GAIN RANGE POWER SWITCHED LOW-GAIN RANGE SQUIB FOWER A _/1 -Z_ FIGURE 10-6. SOIL MECHANICS SURFACE SAMPLEP_ BLOCK DIAGRAM EXPERIMENT SUBSYSTEM, FUNCTIONAL fro FIGURE 10-7. SOIL MECHANICS SURFACE SAMPLER INSTRUMENT PARTIALLY EXTENDED A l t e r n a t e light and d a r k s t r i p e d m a r k i n g s on the inside and outside of the scoop m a y be viewed by the s u r v e y television to d e t e r m i n e penetration depth of the scoop, g r a i n s i z e , and the l e v e l of lunar m a t e r i a l contained within the scoop. Operation of the i n s t r u m e n t c o n s i s t s of manipulation in extension, elevation and a z i m u t h ; disengagement of the elevation d r i v e by a clutch device f o r picking action; r e t r a c t i o n of the extension mechanism along the s u r f a c e for digging; and l o w e r i n g the scoop to the s u r f a c e with the elevation d r i v e disengaged f o r point-topoint mapping of the l u n a r s u r f a c e . The i n s t r u m e n t c a n p e r f o r m l u n a r - s u r f a c e testing within a s e c t o r defined by i t s o p e r a t i n g l i m i t s in azimuth, extension, and r e t r a c t i o n . E i t h e r c o a r s e o r fine 101 incremental movements position the scoop within its sector of operation. fine movements occur in maximum increments of 0.6 inch in extension, degrees in elevation, and 3.0 by degrees in azimuth. Motor control by and The 2.5 or logic coarse fine increment and timing Three ment closes drive selection in the earth command auxiliary is accomplished unit. motors appropriate action instrument series-wound, elevation, door. An scoop the and split-field, and direct-current move motor the instruand in azimuth, the train The scoop extension-retraction. clutch for picking directly solid-state clutch Another disengages action. from the opens electromechanical can fall freely receive controlled one motor the elevation so that the motors and supply clutch are Only power by or spacecraft located 22 in the one vdc unregulated switches instrument time. at the The scoop: a. b. c. d. e. The instrument transducer to indicate excitation sor (ESP). auxiliary instrument unit. will be operated at any mechanism is capable of developing the following forces ExtensionRetractionAzimuthElevation Scoop jaw l-lb radial radial push. pull. at maximum at maximum at edge. precision potentiometers It also system, The has and to indicate two two forcelimit switches receive procesESP. a static extension. extension. 20-1b l-lb either up way or -- 30-1b -- 6-1bs down measured with instrument position systems, fully from open is equipped within an or the envelope of operation. transducer scoop positions. supply through position auxiliary to measure accelerometer fully closed vdc are potentiometers signal the 4.85 outputs potentiometer processed in the engineering mode Their the commutator potentiometer unit for the radial 4 in the In addition, selector picking output and SCO from the elevation instrument is routed processing velocity via during switch action in the only. This is necessary of the scoop at impact. Each signal vertical lated of the two force-transducer and an systems consist of a strain provided gage bridge, a conditioning and amplifier, forces. and interconnecting signal conditioning cable to measure contain regulated a regupower retraction power The a d-c amplifiers 29 vdc bridge supply amplifier. Spacecraft 102 is supplied to the signal conditioning amplifiers which generate a precise bridge excitation voltage. The bridge outputs are routed to a d-c amplifier the output of which is processed via the Mode 4 commutator. One strain gage bridge is located so that elevation forces (from 0 to 3 pounds) can be measured. Another strain gage bridge is mounted so that radial forces from 0 to 20 pounds applied to the scoop along the tape can be measured. An acceleration transducer system, consisting of a sensor, an amplifier, and an interconnecting cable, measures scoop deceleration at impact during picking action. The sensor is mounted on the scoop near the blade. The output signal from the sensor is routed to the amplifier where it is simultaneously amplified through dual channels. The ratio of the two channel gains is approximately 40 to 1 with the amplitude of both channel outputs ranging from 0 to 5 volts dc. When the sensor output is low, the high-gain channel can be monitored. Conversely, when the sensor output is high, the low-gain channel can be monitored. Both channel outputs are routed to the soil mechanics surface sampler auxiliary where, upon earth command, a switch will select the desired gain. The selected output is sent from the instrument auxiliary unit to the telecommunications subsystem, where it is modulated directly upon the main carrier. Two limit switches, mounted on the scoop mechanism, indicate whether the scoop door is fully open or fully closed. The switches are excited by Z9 vdc regulated voltage. The switch outputs are routed to two destinations, (i) to digital channels on the Mode 4 commutator to be transmitted back to earth, and (g) to the instrument auxiliary unit to turn off the scoop motor when the scoop is either fully open or fully closed. The soil mechanics the rmal conditions : surface sampler instrument range is designed for the following Operating temperature Survival temperature -65 to Z57°F -300 to Z57°F Prior to touchdown, the instrument mechanism is secured to the spacecraft by a clamp which may be released by a pyrotechnic device. The pyrotechnic device is energized from a 9. 5 ampere squib power supply in the engineering 103 mechanism A command the auxiliary received and from controlled earth unit by by the a switch in the instrument auxiliary unit. telecommunications decoder in the to the subsystem engineering auxiliary in the is routed mechanism unit. The via instrument and auxiliary subsystem auxiliary command mechanism power simultaneously to a switch turns on the instrument supply simultaneously auxiliary turns and squib power engineering unit. The squib The the switch in the instrument after to prevent approximately inadvertent auxiliary 20 supply off automatically is interlocked milliseconds. of the squib. actuating command firing Instrument The ing, and Auxiliary instrument power Unit auxiliary for are unit provides the command decoding, signal process- management These power an unit. command pulse functions soil mechanics-surface by a 20-command shunt, sampling experiment coma range the instru- subsystem. mand decoder, performed a current subsystem a timer, within switches, SCO, and measuring logic selector ment switch, appropriate circuitry located auxiliary The subsystem provides decoder commands processes required from the the inputs received from the CCD and output in the subsystem instrument decoder auxiliary perform the unit and functions in the listed instrument. in table sec 2 10-i. Commands The or clutch 2 sec/0.1 to either timer limits the operating or time of the instrument (fine). motors Normally, selectprevents fine and and ± 0.4 on seconds in the During (coarse) coarse fine 0. 1 _- 0.02 mode with second the the instrument able upon earth of the time is turned command. elevation timing mode fine mode logic The operating, to the switching instrument. release coarse coarse auxiliary current measuring clutch for motor to prevent and clutch damage intervals operating of the directly instrument. govern The the fine incremental unit during contains scoop movements, a current respectively, shunt only. 4 that The instrument motor measures shunt output extension-retraction is sent to a current retraction in the Mode channel commutator. ALPHA The of craft lunar is SCATTERING alpha surface bombarded scattering materials. with EXPERIMENT experiment A 6 mev portion alpha SUBSYSTEM subsystem of the lunar performs surface Backward compositional adjacent scattered to the analysis space- particles. alpha 104 Z o u ,..-1 I_ o-, m u I u I,-.,I u 0 0 0 o o -t--I E_ 0 0 U 0 _ _ r_ _ _ 0 _ ,._ o ,-_ 0 °,-I o_-I 0 m < E_ o 0 0 0 0 0 _r_ _r_ o 0 0 "_ L0 m m _ m o _ _ o oO U_ u u U3 U_ m 0 _ ,--_ 0 1_ 0 ,-_ ,--_ _ r4 ,-.1 0 u cl _ o_ o_ _ _ _4 4 105 d 0 0 • ,--I "'_ _._ "_ r_ ""_ 0 _1 c_ ,._ C_ v •_ _ _ 0 0 _ ,--t "_ 0 4-_ 0 Z °r4 _ H ,= t.) ,_ o I1) 0 C_ 0 _ o 0 t.) 4_ .el I m 0 N _ _ L) 0 N N _ 0 _ 0 I 0 Z _ m m '..I-I H 0 © ,_g ! Ul © o m S u _ _ m 106 particles, particles, as well are as protons by generated within surface the sample by the incident alpha detected solid-state barrier detectors. Alpha Scattering The alpha Experiment scattering electronics electrical scattering except boron, and Characteristics experiment unit, cables. experiment hydrogen nitrogen, sulfur. and subsystem helium. detects The sodium, proton scattered system alpha detects aluminum, measurement to be surface particles proan subsystem instrument is composed auxiliary of a sensor, unit, a deployment an ir_strument mechanism, The from tons digital and alpha all elements from lithium, phosphorus, from one fluorine, Although the magnesium, of the silicon, varies about sensitivity threshold will be element by weight. than to another, Operation 0.1 micron. the detection of the sensor is expected impaired by 1 percent contaminants The and thicker important alpha scientific particles, measurements and are (I) the energies and of the protons scattered alpha scattered as (2) the intensity The The energy pulse of protons detected particles mined energy by a function height detected of energy. analysis. particles, 9-bit channels of each particle is deterto the coded pulse height, which is proportional signal the which of the is converted words, or which energies parts the to a time comprise is then output, into a 9-bit identify word. These height instrument particles. electronics the pulse of the detected -- the command digital The sensor. converter, sensor uses in the instrument The digital is packaged electronics logic in two contains and the memory width pulses The the circuits, from the power and digital to convert form the variable into synchronous commands This with binary for transmission. controlling ifa command outputs becomes memory of the noisy detectors or spacecraft sensor. to set flip-flops proper operation enables detector is contaminated radioactive material. Sensor Description The sensor, which source The are pulse will be deployed directly with surface to a pulse to the two lunar surface, conand four tains proton a radioactive detectors. outputs data of alpha particles of the alpha detectors type. The detectors are and barrier alpha detector The alpha amplified output applied height-to-time is applied converter. to a gated of the height-to-time converter 107 clock detectors a thin in the are metal alpha scattering to the instrument alpha to detectors stop digital electronics except that the unit. proton To are prevent The proton have similar foil in front detectors registering The that from each the proton of them a proton are pulse the alpha guard and particles. detectors applied background puts inhibits command detector of the the radiation guard proton memory with the as detectors channel control associated event, amplified provided. out- to a discriminator Signals and height-to-time operation of each converter. alpha detector guard detector. the sensor must operate in a vacuum However, source close pressure. Tests large since temperature control the prevent thermal the is provided design temperature of the of the must be of and in required to the For suf- When requires testing for lunar the an measuring alpha instrument, operation source composition, of 25 to 100 millicuries to use alpha are sources obtained may be of Curium-242. the same can at be alpha mounted it is not in vacuum. necessary Weak detector vacuum ficient so that tests, length reproducible a different set spectra of sources atmospheric employed. to avoid to allow The accumulation instrument of low -40°C of enough requires to +50°C special and counts statistical it has an range by operaof a uncertainties. ting temperature to +75°C. treatment a survival range At -166°C 5-watt case temperatures, At high temperature temperatures, finish electricalheater. together from High with rising appropriate above sensor in- surface the survival sensors, at strument temperature. in the sensor and upon in the command The operating instrument from weight sequence earth of the for accuracy unit, the will temperature be monitored electronics to maintain instrument this instrument a. b. regular intervals of this temperature unit follows: requirements is 3.2 +_ 0.2 instrument. A typical electronics is as pounds. Standard Background position). sample-count-- 3 hours 3 hours (sensor (sensor located deployed in stowed position). count to background c. Initial surface). count on the lunar surface-- 6 hours (sensor deployed to lunar d. Data lunar accumulation-surface). minimum of 24 hours of data (sensor deployed to I08 In must between same not order exceed the to obtain 30 reliable and step a data, the of the total interrupted time not in step time c in steps a and The for b minutes, of interrupted step c must 1 hour. hours time the initiation and exceed 7-1/2 reason. Instrument The figure 3-6), The are cps, gated into a identical while 900-kc 7-bit Digital instrument weighs control except the proton clock binary the parity effective check by Electronics digital 5.0 circuits for the & 0.2 for Unit electronics pounds. the two instrument rates. is to word and then This and bit the a parity followed digital 29 vdc The 550 convert is shifted into results bit. by 8 an outputs, alpha cps. the readout The pulse into output in a 9-bit data is unit a logic from storage register word have alpha bit and rate proton is uses sensor to a sync of a pulses, 2200 a unit, located within compartment B (see readout frequency counter 7-.bit readout and word. dead are a 7-bit The circuit the register where consisting been received minimize bit sync since and bit the The operating time, generated. bits a sync within the spacecraft followed previous power voltages 7 data word, If no zeroes generated. generates instrument converter from electronics supply. Instrument The instrument contains oscillators, The ment instrument auxiliary The instrument auxiliary with nificant "one" Source is a Auxiliary instrument and the Unit auxiliary spacecraft'. decoder power switches, unit in is figure and unit are a sync bit unit The capable and similar 10-15. the "Proton Data individual simultaneously by the a ohms. least 7 data Output" SCO's and bits, signals in are with bit. by 5 & 0.25 the from the provides instrument of providing the electrical auxiliary 20 interface unit commands, (see between figure two rectifiers to the seismometer 10-8) the command two subcarrier (SCP_s). instru- three in silicon-controlled appearance auxiliary unit "Alpha digital shown Data Output" electronics These outputs of a parity by is modulates present bit followed instrument NRZ, most A digital volts. sig- unit. a format bit first, digital, the consisting and following volts 5000 and significant "zero" represented impedance 0 ± 0.25 digital approximately 109 The two outputs of the SCOs are in is applied the phase central to a presumming signal processor. onto the amplifier The main carrier and output then of of the to the phase-summing amplifiers amplifiers twophase-summing space craft The in the tran two smitte analog modulated r. outputs both in provided the range by of the high accuracy and temperature are processed sensors by the experiment are 0 to 5 volts ESP. Electrical delivered subsystem controlled power to at by the Z9 power instrument vdc regulated switches from the for the via instrument the and within Z9 payload ZZ vdc operation harness unregulated. instrument Z2 v busses and from active the Power auxiliary are 1.4 aml thermal electrical for unit. the The control power experiment instrument is is power the requirements v and 5 watts, re spe ctively. Deployment The instrument sible position. Support by for and a mounting the sensor, sequence, Me chanism sensor sensor from deployment prior the to mechanism spacecraft to the provides touchdown, background the and means deploying to the for it, stowing in an the irrever- stowed; count; lunar surface for the sensor The the in the stowed position platform in the to standard steel band also (figure serves 10-ga) as a is dust for to provided cover calibration, provide In the mounting the stowed platform. holds the sensor radiation is held mounting sample standard in proper view in proper the position spacecraft sample connected count. to positions relationship factor for by a required position, platform. thermal the sensor place the Release (figure puller the sensor As the lunar as 10-gb) which of is the sensor from by the steel by a the stowed to an the background squib of which count actuated the position pinto the position. band point to ro.tate position. the accomplished activating band. small the explosive orientation band to the release, vertical causing the disconnects is being provided Proper orientation stowed out, past after the drum, toward sensor surface it is rotates count orientation At this deployed mechanism from swings 15 on degrees the background the axis. the background deployment until begins to the the unreels band as it sensor is exert a force arm sensor out sensor count and deployment continue II0 u? Z O© I-.-I I O P_ 0 o > Y LQ ZU._ O--° ZC_ I q. i O @t a O BAND STOWED POSITION ORIENTATION BAND 32 deg ULLER I STANDARD SAMPLE s,oP SA K/;O?NO COMPLETE / DEPLOYED_D ON SURFACE SURFACE ///////" I i.'_'_'_. _ , ' .'o ,A R CL-..'A'." a) Deployment device b) Deployed from stowed position FIGUKE 10-9. ALPHA DEP LO YMENT SCATTER.ING ME CHANISM SENSOR. When arm the and sensor instrument reaches sensor the correct position, and from a detent retains out the deployment slot. in position, sensor the band slips of its disconnect to the lunar Final surface pullers. position second the The from deployment {figure of the 10-9a) puller arm the background by two explosive arm count position The is controlled releases and the the squib background actuated count The pin- first pin allowing deployment to settle detent, sensor spring to the lunar which surface. a pin-puller allowing connection sensor. releases the sensor loaded port and yolk face connects the arm to surface. cable sensor, only the Each viewing sensor to conform to the lunar is the electrical between the the spacecraft of the three switch power pin pullers controlled by utilized command in.the from deployment earth. sequence The weight are ener- gized by of the 113 deployment pounds. The so that the interference surface and mechanism and support, less wiring harness, is approximately 5.5 deployment maximum as mechanism practicable with and view sensor for the are positioned on the spacecraft as little sensor is achieved of the with possible The the operating between the envelope the soil mechanicssampler Z-2. The sampler. relationship sensor on soil mechanics-surface can the be seen in figure the soil the alpha areas scattering spacecraft between common of potential sampler interference are sensor I0-I0. and mechanics-surface illustrated in figure MICROMETEOKITE The momentum, meteoroids DETECTOR detector energy the lunar EXPERIMENT experiment SUBSYSTEM provides lunar ejecta data on the number, microspacecraft. micrometeorite and kinetic of individual surface resulting from impacting in the vicinity of the Surveyor Micrometeorite The and an Detector Characteristics detector experiment both contained cables. how the subsystem in one consists package, The experiment and the an of the sensor micrometeorite electronics and (figure unit are tied associated 10-11) instrument unit, diagram unit instrument subsystem instrument auxiliary block electronics interconnecting shows functionally sensor together. Sensor Description The sensor contains three detectors and bonded two thin signal to an film from impact capacitors the plate with to a the plate, of the unit and detectors each 100 while side KC consisting of a microphone impact related plate. bonded of the common will be The microphone, striking energy sensor crystal, the to the momentum gross of a particle and capacitor Signals applied signals from indicate trajectory are kinetic in the particle. then are A ture. the three instrument detectors amplified unit for to the electronics in the from the heater, digital processing. unit temperaand its output temperature sensor, excitation located voltage through sensor unit, within monitors the ESP It receives a source Mode of 0 to 5 volts A heating is processed 4 commutator. in the the sensor day-night unit, provides terminator. the The proportionally required if the controlled experiment located is operated near 114 Z / _r,3 / / / m_ _m s< / / I sensor receives turned includes circuit. buffer picked acoustical operation is designed power to directly survive from switch the the located and lunar night without 22 vdc heating. unregulated auxiliary as unit are the part The heater and The is sensor spacecraft in the supply unit. on or off by a instrument transducer a buffer Pulses amplifier up by the amplifier from on the the calibration of a calibration routed through The impact and any of the during the is instrument electronics to physically transducer for The sensor shock of the can plate. sensors at microphone calibration assembly capacitor be calibrated transducer. upon Figure command. 10-1Z shows the one from side the from time the sensor and of the its basic is the by field of view. by As mounted on 10 field the spacecraft, on field by other TV of view compartment side camera is sensor A and reduced support approximately structure. 6 percent The because percent of view mast reduced 2 and approximately antenna of the Instrument shadowing omnidirectional B. Electronics instrument analysis detector 10-11. unit counted Unit electronics (PHi) logic unit contains microphone microphone and signals commutation from Every registers. does not cycle and the impact and and capacitor film film as are by clearshown sent a when are to The pulse ing height circuits, circuitry, circuitry, capacitor circuitry sensor unit calibration Energy for and occur, and pulse stored the in figure the momentum height analysis. electronics is registered During a series intervals detector no fed ejecta in accumulation commutator impacts of ones continuously The output hit pulse to the signal telecommunications in this the case will subsystem. resemble will circuits a 001 pulse bits from occurred. bits will the are cycle cycle and to identify height are the used a 100-cps one time the the analyzed for and square read wave. out the As When data the a particle from the occurs, height cycles, commutator (PHi) generate of the Four signal impact and commutator from four analyses it will for from registers. of a data momentum commutator Three from height identify the bits the start word. signal pulse are acoustical used readout transducer. kinetic energy the readout Two bits are out an of the bits used the are analyzed the side capacitors. Three used once The used to out on which accumulation to read energy occurs, is momentum to read when accuit may routed mulation. also be Although cycled by the impact output a command earth. commutator 116 9t'-O_6-OZ E_ -? _E m .J< <{E u)I-H __g. O_z _o_ ) wo O_z _u w OD E o _z O_ _0 3 E -,[ E E .... _-_ 1.3 _Z 0 _ u_ ,--_ U? ®___ I I < -> w iz: I I I I BO.LVIFI_II_OO _3V'Id 03 i [ii I f I zlE_ mow L I .................. ] ........ r- I",. _30003Q ONVI_IflO3 M3J.S.kSBns I o I r,- MICROPHONE 60 DEG 60 DEG THIN AND PLATE FILM MICROPHONE 0 ELECTRONICS PACKAGE Lines limits factor; are and denote angular of sensor view angles indicated both ends of sensor 30 DEG typical of both sides 60 DEG a s s embly FIGURE 10-12. VIEW FACTOR INSTRUMENT OF MICROMETEORITE ASSEMBLY DETECTOR 119 to the instrument monitored Upon tronics through earth auxiliary the Mode command for processing. 4 commutator. the capacitor power The output of the conversion unit is clear circuits in the instrument burn out any elecshorts in unit will generate capacitors. sufficient to electrically the thin film An generates ment craft electronic B+ power conversion for circuit This supply unit (ECU) in the instrument in both unit the sensor electronics and in the from unit instruthe space- elements electronics 29 vdc unit. conversion through receives its power regulated a switch in the instrument auxiliary. Instrument The located ment Auxiliary instrument Unit auxiliary B, unit for the The the micrometeorite interface auxiliary auxiliary decoding, The command detection between unit has unit experiment, the the instrusame in processing, components two in compartment and the Surveyor as provides electrical instrument instrument command experiment. a subsystem spacecraft. physical figure and appearance 10-15. This the seismometer unit performs for the include shown auxiliary signal power management these and functions functions an SCO. electronic decoder, that accomplish power switches, The mand subsystem decodes command decoder receives addressed signals to the from the central comdetector decoder, all commands and furnishes micrometeorite to the experiment electronics subsystem unit and the pulse output commands instrument sensor. Signal lating processing is accomplished with the The in the instrument micrometeorite subcarrier processor auxiliary unit by output modu- a subcarrier oscillator commutator output from to the instrument summing electronics in the unit. central oscillator for is applied via the amplifiers signal transmission telecommunications Two power, regulated other used solid-state subsystem. switches One control the 29 vdc regulated from and and the 22 vdc spacecraft instrument. supply unregulated 29 vdc The respectively. supply used switch controls the power unit in the the instrument from auxiliary the spacecraft in the switch in the controls sensor power 22 vdc unregulated heating element. IZ0 ! w a single, amplifier advantages low frequency amplified coupling by between the two. low-noise The d-c drift from To the preutilize the main is not the high-gain, amplifier. the output by of a balanced arrangement in the preamplifier, output. which and stages The seismometer coil is center-tapped fier is filtered push-pull through an and to provide applied a push-pull of the preamplianother stage of to the modulator The modulated is followed signal amplification. attenuator and amplified of a-c is then applied to the following amplification. It is then demodulated The ments. filtered. structure magnet of the sensor is composed an of four gap, with basic ele- mechanical (1) a cylindrical cylindrical on the same assembly forming within the annular gap, main (2) a fixed several turns center-tapped of wire wound coil centered form magnet but independent consisting 4.5 inches of the of two coil, for instrument and high. calibration, (3) the elastic housing suspension preformed and by springs, 4.0 inches (4) a cylindrical Thermal A control approximately using super in diameter augmented is achieved sensor the insulation a special heater. temperature To is included. instrument, instrument sensor. pulse a start calibrate command produce pulse is routed via calibrate circuitry calibrate in the stop in the electronics The step unit to a current off by output step the is auxiliary calibration Since coil of the command is subsequently transient turned at the after a satisfactory the obtained. stant it is desirable of full-scale to vary to maintain reading calibration output pulse at a cona step with the percentage is used setting independent of the of the gain setting, attenuator the gain the amplitude calibration caging pulse inversely by of the amplifier. the Mechanical support frame. cable. to the is performed clamping by actua- seismometer ting a squib The maximum mass device sensor against to cut Uncaging is performed the holding attached is rigidly spacecraft and The where location at a location where factor Z-g. on due mechanical structure may coupling is afforded the amplification is shown off vertical to spacecraft The seismometer is at a minimum. operate as much as in figure depending 15 degrees the landing The I. 2 _- 0.05 attitude instrument pounds. of the spacecraft. unit, which is located in compartment B, weighs electronics 125 I Instrument The face between Auxiliary instrument the decoding, for capable the Unit auxiliar instrument signal subsystem. of providing rectifier y unit and the (figur Surveyor and auxiliary commands, and instrument one e 10-15) provide s the This electrical unit functions subsystem power oscillator seismic ranging This auxiliary where output current is an signal unit. further analog data, from directly The command switches, (SCO). in the form to Z0 of cps a signal conditioning of the 0 to 5 an one performs inter - spacecraft. power consists two management of electronic a command required decoder processing, The 20 (SCR), of the silicon-controlled The analog with a principal of subcarrier is the output 0 to 5 volts, of within to the signal source containing about the 5000/ohms. instrument signal sensor information l/Z0 impedance oscillator modulates modulated signal subcarrier in is volts signal power payload power age. power turn is routed central processor whose constant provided. is excited processor for the A temperature by a 5-milliampere (ESP). operation from of of watt 29 the of the volts This and signal from source within the engineering Electrical via electrical voltthe signal thermal bus regulated is conditioned of the power and ESP. is control electrical voltage instrument subsystem. 22 volts dc delivered This harness consists Operation and The 0.5 defining through basic dc unregulated of regulated instrument unregulated for requires power. the scientific approximately 3 watts documents 61. payload are listed in Appendix A, items 46 126 SEISMOMETER The and spatial EXPERIMENT seismometer distribution (e.q. seismic such and SUBSYSTEM subsystem moonquakes, noise measures (I)number, noise magnitude, level and experiment of natural background as, effect (2) background spectrum or other correlated, on if possible, lunar surface and with thermal (3) (4) interversus of sources properties of temperature both near materials) at depth; elastic nal structure damping of lunar and and the lunar surface depth, constitution and type - internal and state (number impacts (Q), density versus temperature depth, materials versus depth, and upon (5) distribution the ability meteorite ferentiate impacts between energy moon released quakes). depends to dif- Seismometer The ment auxiliary Experiment seismometer unit, instrument, experiment short suspended coil is period and Subsystem experiment instrument and figure Characteristics subsystem electronics 10-14 is co.asists unit. a functional of Figure block the sensor, 10-13 instrushows of the the seismometer seismometer The gap of a diagram subsystem. seismometer magnet, top relative of the to velocity. quakes) acceleration transducer velocity over the itself, amplifier, output In much However, noise. one-tenth by if To and above specified in the for main the consists which coil, stationary The of a coil as mounted the inertial purposes. induces flat its a voltage response to frequency its natural motion, With experiment range. electronics required it earth, a high has and gain two been by the unit, an instruwithin the mass. flux An Motion permanent wound magnet on serves for auxiliary of the calibration main coil has above suspended to displacement the proportional ground and flat differential (during to the to ground velocity ground is the low small flat sensor noise subsystem frequencies (rate output the of natural response Since is flat that that gain, very of movement) differentiates below ground frequency. this ment response A increases output amplifier is high the natural range, frequency. the overall above in up the than is not this frequency the to the instrument levels located power sensor telecommunications that possible could are the moon gain saturate available is is on on subsystem. seismologically required. background command, is preceded designing quieter this avoid amplifier the true, assumed maximum amplifier gain gain. changes A with possibility, maximum low noise one-hundredth chopper-amplifier a direct-coupled, preamplifier 121 i CABLE ACCESS DOOR OUTER SHELL SUPER NSULATION MOUNTING (IOF3) DIA 7 in, 7.8 in. FASTENER HEIGHT FIGURE 10-13. SEISMOMETER INSTRUMENT 122 FIGURE 10-15. SEISMOMETER INSTRUMENT AUXILIARY UNIT 127 , / Xl. SPACECRAFT MASS PROPERTIES WEIGHT Total launch spacecraft weight is limited 2150 pounds. II-I by the A and months meets capability weight The of the Atlas/Centaur breakdown payload (as for vehicle to a nominal is given detailed 11-2. of 19 June each an mission 1964) in tables specific of the cg will be payload selected combination since shown, several which in advance weight of the and flight to provide This all five optimum constraints. including selection scientific Centaur. Fluctuations given is necessary experiments Those the total weight exceed required spacecraft, capabilities may not the boost for of the Atlas/ will be of the may be deleted. instruments details a particular in periodic weight Status mission revision status Report. in exact of design the current result figures in this table; by referring however, to the spacecraft Weight obtained current Surveyor CENTER OF GRAVITY AND INEKTIAS radius-of-gyration, major and configurations: retromaneuvers The limits and moment-of-inertia for launch at Spacecraft conditions are center-of-gravity, specified deployed for for three stowed liftoff weight; and deployed midcourse at landed defined along at separated of the weight; for touchdown plane are weight. center-of-gravity and the limits last of travel the in the X-Y by the first two the Z-axis are conditions, by center-of-gravity s. travel defined the first and condition Spacecraft-center-of-gravity weight are shown in figure Ii-I as limits in the stowed configuration at launch and established by Atlas/Centaur control stability capabilities. ravity are vernier limits after by Surveyor/Centaur the attitude separation for midcour of the The with se Center-of-g and retro maneuvers and limited engine correction capabilities flight control subsystems during retro-rocket burning. coincides spacecraft center of gravity, before retro-rocket installation, 129 TABLE Ii-I. SURVEYORA-ZIA WEIGHT SUMMARY Weight* (pounds) 698.81 1432.08 90.01 2221.90 624,72 Element Basic U sable Scientific Separated Landed bus propellant payload weight weight *Based on Payload Combination 1 TABLE II-2. SURVEYOR A-ZlA DETAILED WEIGHT STATUS Design (pounds) Item Basic Flight Sensor Inertial Canopus Wiring Electronics Support Sensor Attitude Attitude N Z tank Actuator, Nitrogen Bus control group Description Current Weight 698.81 system flight control unit 49.0Z 35.39 8.13 4.9Z 0.95 17.89 3.50 secondary control jets and roll control solar system 0.35 13.28 1.62 9.08 1.08 1.50 reference sensor harness 130 TABLE 11-2. SURVEYOR A-Z1A DETAILED WEIGHT STATUS Current Weight 103.86 (Cont) De sign (pounds) Item Electronics Data link Description 32.29 planar array A B 8.90 0.32 0.32 0.83 0.48 A B receiver A receiver B command signal decoder processor system 5.44 4.85 34.18 9.64 10.62 sensor 6.60 6.02 1.30 6.78 6.8O 5.73 3.35 and 3.88 and 6.84 6.84 3.88 Antenna, Antenna, Antenna, Rf Rf transfer spdt omnidirectional omnidirectional switch switch Transmitter Transmitter Command transponder Command transponder Central Central Doppler Signal Klystron Antenna, Antenna, Waveguide Boost Approach Engineering Engineering regulator TV altitude/velocity data converter power altitude velocity assembly supply / velocity sensor camera signal mechanism 4 processor auxiliary 131 TABLE 11-2. SURVEYOR A-21A DETAILED WEIGHT STATUS Current Weight (Cont) Design (pounds) Item Thermal Altitude Description assembly radar marking radar control marking 0.24 8.43 0.92 0.34 3.30 O.6O 54.90 8.50 46.40 28.55 Insulation, Signal Battery Low data proce altitude s sing auxiliary charge rate regulator auxiliary Electrical Solar Battery Mechanisms Positioner, Boom Boom Power panel antenna/solar panel antenna antenna arming A B 24.38 2.20 1.16 0.81 218.46 etc, omnidirectional etc, omnidirectional sensing vehicle basic hardware structure and Separation Spacecraft Spaceframe, Installation The rmal 59.87 22.54 1.00 38.28 11.63 11.63 11.63 paint gear gear gear gear gr installation I 2 3 rel (3) blocks A Landing Landing Landing Landing Pin puller, 0.33 3.06 25.16 Auxiliary Thermal crushable compartment 132 TABLE ll-Z. Item Thermal Wire Pneumatic Release Engineering Latch, Heat SURVEYORA-ZlA Description B bus DETAILED WEIGHT STATUS (Cont) Current Weight De sign (pounds) 18.06 44.20 0.74 compartment harness, line mechanism, measurement spacecraft collectors propulsion system, to basic s main retro sensors 1.50 4.45 0.33 0.78 223.16 Centaur Spacecraft Propulsion Valve Tank, Tank, Tank, Thrust The rmal Lines Helium Propellant, Rocket Rocket vernier helium 73.42 3.04 20.31 assembly, helium fuel (3) 9.96 (3) assembly (3) 9.96 18.44 5.62 fittings 6.09 2.50 oxidizer chamber control and miscellaneous unusable main main retro retro retro 4.20 143.04 139.39 3.65 8.00 engine, engine, Insulation, Contingency Propellant, Ve rnier main usable propellant propellant 1433.08 156.50 1236. Z0 Retro-Rocket 133 2.2 1.0 ÷Y "I -FX SEE INTERFACE CONTROL DRAWING o° 'L CG LIMITS FROM STATION 89 TO 118 --y VIEW (o) CG ENVELOPE , /-:,,,,,,,,,,. /::7 +Y I _i'.':".".". C i05 53D + X 36 77D SECTION PAYLOAD A-A ENVELOP'E ONLY I I o 1' viEW I STA _B O0 CONICAL FLATTENED TO CLEAR .NOSE )E_ FAIRING (SEE SURFACE 2 75 NOSE B-B) ,n 2500 A I STA 6DO(REF) , (e) STA 157 22 SECTION LONGERON I/llk C SEE iNTERFACE DRAWING GDA FOR LOCAL RESTRICTIONS CONTROL 55-00050 ENVELOPE SECTION C-C DIMENSIONS IN INCHES SECTION6--8 FIGUKE II-I. ATLAS/CENTAUR PAYLOAD ENVELOPE the Z-axis within 1.0 inch. must The spacecraft with the center retro-rocket of gravity thrust to coincide the for the axis with separated 0.18 center inch of weight radial. gravity to meet conditions The coincide of the thrust within the position time axis is adjusted with at the this The of installation to coinciae spacecraft center of gravity requirement. of travel are of the vertical center-of-gravity location in the touchin limits down Section configuration XIII, so the designed to the landing will not topple site assumptions, when landing. described spacecraft 134 EFFECTS OF PAYLOAD COMBINATIONS The concept of designing the spacecraft for autonomous operation and removal of one or more of the approved scientific instruments has been outlined in the previous sections. The approved list of scientific experiment for the A-21A series of spacecraft consists of the following: Survey television experiment subsystem (which can include either one or both of two television cameras) Soil mechanics-surface Alpha scattering Micrometeorite Seismometer sampler experiment subsystem subsystem subsystem subsystems experiment detector experiment experiment subsystem The television experiment can be installed in any of three different combinations (i.e., TV camera 3 only, TV camera 2 only, or both TV cameras). When it is added to the other four experiments the total could be considered potentially as seven different possible experiment combinations. However, because of the relative locations of the television cameras on the spaceframe, the use of TV camera 2 by itself is not considered practical. Its capability to view the other scientific instruments is inferior to that of TV camera 3. Furthermore, its location is not as advantageous for center-of-gravity adjustment purposes as that of TV camera 3. Accordingly, the possible television combinations are restricted to I) TV camera 3 only, or (2)both TV cameras 3 and 2. The scheme employed in analyzing weight and balance effects consists of starting with a full complement of scientific experiments and then removing them in various combinations, to achieve particular configurations. In some cases removal of one or more experiment subsystems requires that ballast be added to either leg No. 2 or No. 3, or both, to keep the spacecraft lateral center of gravity within acceptable limits. Ballast is added at the footpad in increments of one pound up to a maximum weight of five pounds per leg. Use of ballast in excess of this figure potentially requires redesign of the leg and extension me chani sin. In some instances proper cg control cannot be achieved by adding 5 pounds at one or more footpads. In these cases it would be necessary to add supplemental ballast on or near the main spaceframe structure to achieve proper cg position. 135 An itemized weight summary for each scientific payload experiment is given in Table 11-3. Table ii-4 illustrates 13 different payload combinations considered. (Those combinations previously studied but which could not be brought into proper balance by adding footpad ballast have not been shown.) When the total dry landed weight of the spacecraft drops it will be necessary to add supplemental ballast (which can be around the geometric center of the spaceframe) to enable final made consistent with the minimum vernier engine thrust level chain ber. below 586 pounds, evenly distributed descent to be of 30 pounds per As various payload combinations are selected for flight it will be necessary to provide the vernier fuel and oxidizer necessary to accommodate the total spacecraft/payload weight including ballast (if any). The total amount of main retro propellant loaded must also be adjusted for total spacecraft weight. SPACECRAFT Spacecraft system is Z Z No. so as the axis axis, 1. to The formed ment by Ievel Since tooling plane is hoIes 23.75 whose height is the The make origin three between the on or axes COORDINATE components are denoted length top of the SYSTEM are X, of located Y, the and by Z. a right The Z A X-Y the hand Cartesian axis movement is line the perpendicular of spacecraft direction coordinate (figure along to 2-2) the the leg taken coordinate negative plane vertical the spacecraft. the is to the right at The along toward positive X axis the spacecraft, axis Y coordinate is perpendicular system the bali Surveyor system are the axes being but Tolerances in the X-Y may on plane, used X-Y holes. center with Y axis, handed. the X-Y and is geometric plane the no the positive coordinate lies tooling the in plane center is approximateiy of a triangle the adapter. attach- vehicle origin to locate Surveyor-Centaur physical origin. point The on origin the coordinate the legs from roll spacecraft, in the X-Y inches yaw the and origin tooling are as holes. defined as above. with center of = -16 changes gravity to -19.5 the spacecraft The location in are component withina inches (above X, of Y and the Z axes center location one inch theX-Y of and radius Pitch, respectively, gravity weight from plane). is defined change the and determined, changes. the origin Z 136 C - "D b-, Z 1'-4 _ -_ _, _ .o o_-_ _ _ __ "0 ,,o -P _'_ o o o X _E A 0 "o -Z ._.__ 0_0> I.,J 0 .o, • c_c_ ' j 41 J -I- I 41 4¢ r_ + i d e_ £ 6 O" 0 0 Cl J 4t J 4t e_ t_ Z 0 '-o o oo c; -2 o c_ ._ I_ o f_ 44 o 0 6 J 44 6 41 J 41 41 o c_ O > 0 oo. .2 .2 .2 6 N O _ 0 66 4u t) N I = 6 6 4, o. J 4-1 J 4_ J tt_ iJ _ "_ © ,2 _4 o" q_ o D _ I. c_ 41 J 4t 6 o o_ -_ _._ ,g ?: _ _ _0 g 6 41 '_E'_ ° g c_ .tt Cr- 6 41 6 4t e_ o9 6 4t O t_ _O N _,_o o o _J 6 o. J _o ¢x! o 1"--4 41 o 6 4t o 6 4t 6 4t 6 4t _ o ! ,g i E_ Oe_l 0_'_ o 137 TABLE II-4. PAYLOAD COMBINATIONS SUMMARY Spacec Experiment Payload Combination Number TV Camera 3 Both TV Cameras Combinations PayZo&d Weightp pounds Resulting Center of Gravity, inches X Y Z raft Design Total Usable Propellant Weilht, pounds Results Surface Sampler Micrometeorite Detector BILllast Weight (ff amy), pounds Leg 2 Leg 3 Alpha Scattering Seismometer Spacecraft Gross Wolght, pounds Dry Landed Weight, rounds Propellant Weight - lb Ve ruierl Retro I Z 3 4 5 6 7 8 9 10* 11 IZ X X X X X X X X X X X X X X X X X X X 90.01 8Z. II 0.10 0. Z0 0.26 0.2,! 0.37 0.39 0.73 0.72 0.47 0.54 0.69 0.78 0.54 0. Z3 0.19 0.35 0.49 0.30 0.62 0.36 0.34 0.67 0, 55 0.4Z 0.23 0.64 0. Z5 0. Z8 0.44 0.54 0.48 0.73 0.81 0.80 0.81 0.77 0.81 0.81 0,84 4. Z0 Z. 50 0.70 Z. 60 1433.08 1416,84 1414.94 1399.50 1398.40 1381.26 1379.48 1394. 1368.9Z 136Z. 1367.80 1368.15 1353.71 Z6 17 ZZ21.90 Z197.76 2194.81 Z171.9Z ZlTO. 2144.73 Z142. Z163.96 Z 126. 2116.46 2124.69 2125.19 Zl0_, 67 38 lZ 37 624.72 616.82 615.77 606.32 607.87 599.37 598.54 605.69 593.36 590. 592.79 592.94 585.86 l0 151.38 149.74 149. 54 148.00 147.90 146.26 147.47 145.96 144.92 144, 144.80 144.85 143.41 26 1281, 1267. 1265.4 7 I X X X X X 81.06 73.61 73.16 64.66 IZSI. 5 I:_50.5 1Z35, 1246.7 1233.5 1224.0 1218.0 IZZ3.0 1223.3 1210.3 0 X X X X X X X .X X 61.33 70.28 56.05 5q. _9 X X X X X X X X q_.88 q_.4_ 48.15 4.80 {. O0 *includes *:',_nciudes I. 64 pounds pounds ballast, ballast, evenly evenly distributed distributed about about the the geometric geometric center, center, to obtain to obtain minimum minimum dry-laJrKled dryli&nded weight weight o1 of 586 586 pounds. pounds, h, 00 Note: Weight and balance assumptions tank located at are: x y = • 0.00 -3_._0 Nitrogen Signal data converter located at x y = = I. 00 -Z;.O0 Weights aqe as of 19 June 1964 weight report Locations and weights of scientific payload primary instrument or sensor are: Weight Y Survey Survey Surface TV TV camera camera 2 3 -31. Z0 6.50 96 ZO ._. 8£.90 79.85 31. O0 {pound 15.96 13.96 g. 80 8) 15.00 23. O0 -Zq. -3_. Sampler detector Micrometeorite Seismometer Alpha scattering 7.50 .10,56 IO. 50 - 16. O0 -Zl.00 - 34.00 g6.34 5Z,16 70.87 2. O0 S,80 3. 20 138 XII. SPACECRAFT THERMAL CONTROL To passive design adequate while low and obtain thermal maximum control by reliability techniques the requirement over the with have minimum ben used complexity, wherever with passive and semi- practicable. a minimum long wide weight periods range This penalty, was dictated to achieve, for thermal on control a lunar spacecraft having an relatively of time of high and operating temperatures. lightweight surface passive exceptionally control Although solution and thermal operational provides a relatively simple to real-time thermal problems, and it required surface control which of thermal is the development treatments achieved control these control having through temperature control power veriffication thermal of special properties. insulation techniques unique the use by Semipassive thermal thermal of self-actuating varying the thermal active held mechanical conductivity. heating switches Through utilization and techniques, consumption electrical requirements are to a minimum. METHODS The or unit OF THERMAL thermal CONTROL control system consists to provide of spacecraft of the individual subsystem environpassive surfaces and (2) Surveyor thermal for control systems, during integrated all phases acceptable operation. thermal The ments methods all components include thermal employed optimum (I) special absorption to house heaters, preparation and of spacecraft external to achieve emissive characteristics, The paths compartment active superJ_nsulated employed are compartments (i) electrical operated acceptable critical (2) thermal equipment. conduction the methods by controlled bimetallically tures within The a. thermal limits. thermal will except switches to maintain tempera- spacecraft The control remain during design with the is based on the following (Z) axis assumptions: pointed spacecraft the sun the positive-thrust following periods: toward 139 (I) (2) (3) (4) h. Before An initial sun period acquisition. of 1 hour maximum (full shadow). eclipse Midcourse Terminal the will normal be correction descent transit pointed is 442 at maneuver. maneuver. attitude, the Btu/hr-ft of the from sun. z nominal illuminated zenith. of solar The angle (same lunar surface in as during is temperature accordance with transit). +Z60°F is figure at a the positive thrust axis of the space- For craft C° Solar Maximum solar assumed iZ-l. intensity d. temperature angle to of vary 0 degrees as surface a function el Radiative properties of lunar surface: c = G = 0.875 0.93 Infrared Solar emissivity absorptivity 300 ASSUUPT_ONS u/2 ,. DUST :0 g3 B?_ w/fl I LUNAR OEPTl'l TEMPERATURE : $ ft : 40°F OvER HOMOGENEOUS l ROCK OSO,.ao t,mm : 0 S:I$0 ADIABATIC ADIABATIC MATF ROCK RIAL PROPERTIES OuST -ISO i _i) C I 21 IBT 02 Btu/hr Ill/|l' Btu/IO "OF'ftl • 2SI10 ii2 Ih/fl -4 | Btu/hr-OF-ft , "OF 02 etu/IO "°F 1 120 SOLAR 240 ANGLE, DEGREES 3GO LUNAqNO(_ FIGURE 12-1. LUNAR SURFACE TEMPERATURE 140 f, Minimum and temperature at 65 degrees of lunar surface at night is -Z45°F at the equator -260 °F latitude. 141 PRECEDING; PAGE _LANK NOT FILCHED. XIII. OPERATIONAL SEQUENCE AND FUNCTIONAL PERFORMANCE The mission craft expected is described performance of the spacecraft during a standard operational on space- in the following based The on design paragraphs. capabilities phases and Emphasis their is placed to the are performance phases. and lunar. relation mission mission operational transit, three major of a typical prelaunch, PRELAU NCH PHASE Air Force The Eastern AFETR Test imposes Range (AFETR) constraints are on the spacecraft, primarily The such conto various measures AFMTCP ensure "General straints that adequate Range as are Safety safety Plan," provided to protect personnel. for 80-?, provides the authority constraints reflected are must in the spacecraft as design. Typical affecting spacecraft a. design Squibs for summarized be capable follows: an energy of 1 watt at 1 ampere of withstanding firing. system, destruction nitrogen capable 5 minutes explosive be without destruct for b. An must of actuation propellant tanks) by radio command, by GD/A). provided vessels of solid and (provided must meet c. Pressure proof (i.e., helium minimum test requirements. and arming must mechanism be provided. such as as those launch listed azimuth above. conditions do not influence to ensure against inadvertent retro- d. A safe rocket Other the spacecraft AFETR firing restrictions as directly design Prelaunch The than a few Operations final at AFETR countdown and safety check circuits on the Surveyor that are spacecraft wired itself to meet (other prelaunch power critical hard-line 143 AFETR requirements) is accomplished by means of an r-f link. Inherent in this checkout is the operational verification of the spacecraft transmitter, receiver, command decoding, and signal processing. During this countdown, the spacecraft pulse code modulation (PCM) data channels and Centaur telemetry can be monitored to provide the initial-condition values for these channels. Checks of the television and spacecraft transponder operation, as well as the ability of the spacecraft power system to properly supply the electrical load (i.e., with external power removed) can also be made. The success of the mission is dependent on the establishment of definite initial conditions for some of the spacecraft subsystems. At the time of launch, the spacecraft battery must be fully charged, the marking range of the altitude marking radar selected, the Canopus sensor field of view adjusted properly for the particular launch data, the gyro temperatures within their operational range, and the temperatures of some spacecraft items such as the retro-rocket, vernier propellant, shock absorbers, compartments A and B, flight control electronics, and Canopus sensor at their prescribed launch values. Once the spacecraft is launched, external control of the spacecraft is not available until the initial DSIF acquisition is accomplished. Therefore, spacecraft operational conditions required during this interval must be established during the final countdown. These conditions are as follows: a. Flight control coast system imparted can must be be phase must electronics be in the must be on, and mode of the the spacecraft so that the flight control angular from b. The rates Centaur nitrogen rate-stabilized as a result to the nulled. inhibited spacecraft separation from flowing to the jets so that it will be conserved c. The to be d. One tion during countdown amplifiers via and the and boost, be until Centaur on to permit provided separation. accelerometer by the Centaur. data accelerometer transmitted transmitter must be on must telemetry channels its associated time of launch receiver/transponder to permit and interconnecto facilitate the at the initial DSIF e. The acquisition. traveling-wave will be ready tube for (TWT) high filaments power must be when on so the transmitter that the transmitter operation 144 preseparation is received f. command from for spacecraft transmitter high power turnon the Centaur. signal processor of PCM must data be operating in the proper and and the mode space- The spacecraft to provide craft the one channel during via the Centaur boost telemetry links the period between the completion of the initial DSIF acquisition. TRANSIT PHASE The a. b. c. d. e. f. g. h. i. transit Launch DSIF Sun phase through of the Surveyor separation. mission includes the following events: acquisition. acquisition. acquis_ion phase I. correction Z. descent de scent. retro descent. maneuver. maneuver. and verification. Can.pus Coast Midcourse Coast phase Pre-terminal Terminal I. 2. 3. Main Vernier Touchdown. descent. Launch thru Separation are included via on the spacecraft telemetry simultaneously be available to permit system the telemetering during this phase via the the of PCM of the spaceof Provisions and accelerometer This data same system from the by PCM the Centaur data will be mission. craft the telemetered following data telemetry spacecraft so that it will The also separation the boost Centaur. the accelerometer will indicate vibration For certain experienced the spacecraft must spacecraft. properly after it separates from Signals the Centaur, that will to perform be operations accomplished before separation. 145 cause these operations to occur are to be provided by the Centaur. operations are described in the following paragraphs. Required The landing gear and omnidirectional antennas are launched in their stowed (i.e., nonextended) positions so that the spacecraft can fit within the envelope of the shroud. The landing gear must be extended if the cold gas attitude control system is to operate properly since the attitude jets are installed near the ends of the legs and their moment control capability depends on the legs being extended. Consequently, gas jet actuation is inhibited until the legs are extended. The omnidirectional antennas must also be extended to provide the desired radiation pattern coverage for accomplishing the initial DSIF acquisition; the spacecraft high-power transmitter must be turned on to ensure that a signal of sufficient amplitude will be available for accomplishing the initial DSIF acquisition; and the solar panel must be aligned so that it can convert solar energy into electrical power. Although it is possible to command these functions from the ground in the event that the Centaur fails to deliver the signals required by the spacecraft, the ground-to-spacecraft communication link must be established before this can be done. The reduction of possible separation-induced angular rotation is accomplished by the coast phase attitude control system operating in a rate-stabilized mode. The coast phase attitude control system controls the spacecraft attitude by operating the three pairs of nitrogen gas jets located on the ends of the landing legs, and as indicated in table 13-I, it is the system used for attitude control throughout transit except during the midcourse and terminal descent thrusting phases. In the rate-stabilized mode, the system closes an electrical feedback loop around each of the gyros so that the spacecraft rotational rates about each of the spacecraft axes are sensed and reduced to approximately zero. To keep the gyro gimbals from hitting their stops and to limit the amount of nitrogen used to stabilize the vehicle (approximately l percent of the total amount carried), the rotational rates induced by separation are required to be less than 3 deg/sec. The spacecraft is mechanized so that two signals automatically generated during the preseparation and separation sequences enable the gas jet system. These signals are (1) a signal produced by all three landing legs extending in response to the Centaur command described previously, and (Z) a signal generated by the separation of the spacecraft from the Centaur. As a backup, 146 TABLE 13-1. SUMMARY BY COAST PHASE OF OPERATIONAL ATTITUDE CONTROL MODES PROVIDED SYSTEM Phase When Immediately separation re(within spacecraft C entau r of from of Mission Utilized after Operational Mode Closed around Mechanization electrical gyros rates so are Description loop that provided spacecraft and zero R ate - s tabiliz ed mode angular duced the Inertial mode sensed to approximately dead-band). so system System angular space the operates position are sensed. that changes in in During midcourse pre- of spacecraft The correction, of retro retro phase, phase, burning attitude spacecraft is controlled in space. so that it remains fixed during endesand tire vernier cent during stant portion and Maneuvers Mechanization mode, applie_l time This except is same as inertial current for the is yaw for roll, con- the velocity for pitch Before and midcour se that a fixed torquer terminal to the gyro descent commanded current from results the ground. in a nominal for in a spacecraft the commanded given Automatic acquisition sun rate of 0. 5 deg/sec time, movement. resulting angular Spacecraft sec in yaw maneuvered and sun pitch sensor at 0. 5 deg/ in response logic sensor to Sun acquisition secondary appears view. until sun field of in primary 147 TABLE BY 13-I. COAST SUMMARY PHASE OF ATTITUDE OPERATIONAL CONTROL MODES SYSTEM PROVIDED (Cont) Phase When of Mission Utilized acquisi- Ope rational Mode star Mechanization Spacecraft sec maneuvered De sc ription at 0.5 deg/ Automatic acquisition Canopus tion in roll until Canopus appears within sensor. Optical c ele s tial) (or field of view of Canopus Spacecraft controlled by primary pitch by and yaw attitude provided spaceby Coast phases error signals and refe renc e sun sensor, craft error Canopus roll attitude signal controlled by the provided sensor. commands system nonstandard to which be shut either off at permit any time the gas during jet system are to be enabled to or permit the transit provided accommodate situations. solar generated solar panel panel when launch-lock of the solar which motor. is relock by a third to deployment the spacecraft pin panel in When transferred limit limit the switch. switch automatic turn the to pullers axis is is initiated senses and the by two separation roll by axis a limit train position motor relock is is squib-firing from the pulses. Centaur, pin that pulses reached, through position disabled. is to Automatic These initiate puller. initiates the the the solar pulse use of it DSIF pulses, the The launch-lock switch of is unlocking generator, stepping sensed a pulse panel generator a solar is supplies solar the a continuous panel roll axis the the pulse roll relock output panel stepping axis generator logic When and reached, After off. sensed acquisition, power deployment commanded DSIF Acquisition The communication and and must on tracked locate to this the signal. maintained during link by the between the DSIF the spacecraft to the first and permit step and tune the the in ground spacecraft this the have sequence, ground been must to be be the receiver standard, con- established trolled DSIF to 148 lock stations As mission. transmitter spacecraft If the signal separation boost and phases the spacecraft will come within view mitters band data operating voltage-controlled over one to of the in pull-in the two in the high-power oscillator, spacecraft transmitter the of ground the of mode, the tracking frequency station controlled one The the with one by of of its its narrow trans- and omni transmitting antennas. during is receiver. since frequency with the will be channel spacecraft second until will part its engineering receiver of the can acquisi- phase-lock tion within the procedure the spacecraft ground which range signal transmitter tuned This signal result of by ground in appears a shift in spacecraft transmitter the spacecraft frequency, frequency, transmitter which in turn achievement be controlled by the transponder the space- operation, craft receiver will controlled transmitter. With power The time mitter quency the spacecraft at the transmitter antenna feed operating will typically to change of the in the high-power be from a minimum the time change mode, the r-f appearing transmitter of Z. 7 watts. of launch which to the the transfreof the frequency is expected because of acquisition, experiences will be primarily during temperature spacecraft The million this period, at the time so that the transmitter uncertain of acquisition. ±Z0 parts per frequency (ppm) stability with transmitter ture is expected of less circularly to be than within a tempera- coefficient The two used 0.5 ppm/°F. omnidirectional reception the same but only antennas mounted on for the the space- polarized for craft sion. are simultaneously antennas do one-at-a-time throughout They tend are transmisentire on 471" the of These not have level of gain steradians, spacecraft the other. over until tinent only primarily so At one because of spacecraft shadowing. antenna installed that the nulls the time in the pattern of one the to cover will be over the peaks of acquisition, and cannot the be since commanded transmitter to transmit by one transmitting antenna is per- antenna the other alone acquisition is achieved, coverage Also, provided since both antenna to spacecraft transmission. the mission, reception. coverage -i0 a gain receivers by will be both operating is of continuously concern The provide possible upper for throughout spacecraft the coverage provided antennas composite of the two db for antennas used for over receiving 99 percent will typically of the the polarizaan a gain aspect hemisphere the of at least angles, of the single polarization -6 db for dual of at least and polarization -7 db for must over dual spacecraft, a gain of at least however, tion over lower hemisphere. Transmission, consider 149 appreciably Thus, for lower antenna gain gain whenever the spacecraft attitude is unknown. at least than -30 -30 db db over the typical of the possible antenna aspect at this time angles, with is expected no nulls to be deeper 99 percent of the 10 degrees There can be wide. is a constraint continuously on on the amount high power of time in the that the transit spacecraft environment high-power transmitter expected operation temperin operated the launch-to-acquisition will result in the period. power Continuous amplifier operation within transmitter tube transmitter exceeding its operating ature. Thus, since must Under Z0 the high-power be accomplished standard is initiated 1 hour the after just before launch or separation, the transmitter to be to high tem- the acquisition will overheat. acquired power, perature Each within and conditions, after commanded spacecraft is expected is switched minutes maximum can be the transmitter to low power the transmitter indicates if telemetered data that the transmitter receivers receiver. (I) a noise 13.5 kc for A is overheated. crystal mixer to have the of the spacecraft FM is a conventional typical no receiver greater superheterodyne-type following width is expected than 14 db, into the the characteristics: more than figure (2) a bandreceiver, signal is of no getting a ground command (3) a threshold centered least 40 signal-to-noise ratio in this bandwidth than 12 db, and (assuming (4) a dynamic is the same in the passband) db. The stability of greater of the so that (to which range as of at spacecraft receivers in the that of the spaceduring of transat the time spacecraft craft transmitters, frequency is the As be the uncertainty the ground knowledge must be of the tuned receiver transmitter in the previous the the acquisition) mitter stability. same as that indicated discussion in the case reduced by of the transmitters, measuring the uncertainty frequency of acquisition launch. The the mission static This one can receiver just before channel of PGM signals error, data which which can is being transmitted acquisition transponder during (such as this phase of includes phase data aid in the agc, the the transsignal, ponder etc.). the the receiver phase-lock modulates carrier a subcarrier The signal which, in turn, phase-modulates to modulate percentage enhancing the the of transmitter signal signal. a low subcarrier index center oscillator so utilized high carrier provides power modulation that a very the transmitted probability is in the carrier receiver frequency the carrier thereby signal. of the ground acquiring 150 Sun Acquisition The spacecraft relative next to during can in begin establishing descent in produced control sun sun be response by subsystem sensors. sensor stepped before deployment if the solar is mounted on the solar from panel the (figure stowed Under by spaceit can solar about by the to must the acquire sun transit convert on and which depends, solar lock the on passive (2) energy and accurate The a single jet align into to the sun to (1) establish of so most that it the vehicle spacecraft faces power, the the attitude thermal the solar control panel electrical reference and components sun and (3) and aid and required vehicle acquisition command The with gas signals a known maneuvers. to before lockon by a are sequence is by midcourse terminal accomplished of spacecraft by automatically maneuvers the and the solar flight primary secondary panel must ground system. gas in jet system provided controlled the secondary Because 13-i), position normal craft be the accordance to its transit sun acquisition of the panel solar position can panel be in which conditions, it is launched automatic achieved. is initiated Centaur separation, by array means is not deployed To automatically, this, the accomplished of ground must the commands. be rotated then accomplish panel/planar the 85 spacecraft degrees. combination and approximately rotated by up 60 degrees from the roll axis, These solar panel roll axis will rotations, when accomplished increments the active ground per command, When result solar in a stepping panel ular craft. At attitude of the panel in i/8-degree position, and be command. of the panel of the the the is stepped to the The the to its transit roll axis can face is perpendicspace- spacecraft spacecraft time the points commanded in the direction to acquire command top of the then sun. the sun, its spacecraft random. receives The the to acquire of the sun from is expected involves to be acquisition this random by the flight is orientation control first mined axis a sequence at a nominal the spacecraft yaw axes, of rotations rate yaw and (controlled deg/sec. sun automatically In general, programmer) about of 0.5 axis the vehicle deterpitch rotated by until The the the until the rotated sun lies in the plane the spacecraft roll and roll axis is then about is within of the the primary sun sensor field of view. hemisphere. Each hemisphere that quadrant. for the of of field of view cells of this and secondary has a view sensor is one the four the sensor of one signal quadrant the of the upper sun is within rate spacecraft output provides are an output processed when 0.5 These signals to produce deg/sec commands 151 @ PLANAR ARRAY ANTENNA FLIGHT CONTROL GROUP SOLAR PANI PRIMARY SUN SENSOR PARALLEL TO S/C ROLL AXIS) SECONDARY SUN SENSOR SOLAR PANEL) (PERPENDICULAR TO FIGURE 13-I. SUN SENSORS, LOCATIONS AND ORIENTATIONS 152 yaw no and secondary pitch attitude sun sensor control ceil will in moves signal the loops is still sun's within is as indicated (i.e., in figure sun is 13-Z. not in a yaw field primary to is is of In the the upper event hemi- that illuminated be commanded sphere), will the eventuaily When spacecraft result the sun to in the execute sensor of is sun the maneuver view. sun the sensor, optical on parallel pitch and to which appearing the field and The and 13-1). has of view control a mode top to yaw the of sun Jn the the error signals lockonindicate both flight spacecraft angles provided Sun lockon that is the pitch control roll and generated switched sensor that nulling system yaw channels. group (figure by primary primary a field of mounted sensor axis view aligned of in the Simultaneous attitude sensor. control accomplished by must certain the the sun response be parts achieved of the within spacecraft an estimated do not time suffer of 1 hour after damage launch due to to ensure extremely permanent high or low temperature. Canopus With trolled. desired established. The which the to star the is Acquisition the Before to thrust spacecraft the in and Verification locked on of direction the to the sun, only and space, the pitch-yaw descent, roll attitude attitude where must is conit be is execution a given midcourse in inertial terminal the spacecraft adjusted canopus before will attitude. in while to roll a is mechanized launch so within ground roll to that its accomplish with field the of to gas jet this spacecraft view when by means locked the of on a star to the is star rate spacecraft sensor sun, rolled acquiof appear The spacecraft automatic the nominal The expected occurs, by proper results command via remains the initiate system on to the at the (i. e., When is sition 0.5 spacecraft the spacecraft a star in the star deg/sec locked brightness field the roll of sun. the this controlled continues nes_ signal signai until appears by by the the of the the proper brighta lockon the error of Canopus) is generated sensor and view. attitude sensor, sensor. sensor field that of the can developed Although Canopus sensor to verify is view, designed it also on to discriminate an the by sensor commanding output against signal is actuaily the star sensor stars which that may makes indeed to appear it in possible the provides which object be roll locked spacecraft output is Canopus. a Verification complete 360-degree accomplished while the perform telemetered 153 MANEUVER / ', i \ ...... _.._, ...... ..... +,,,_, SECONDARY SUN SENSOR AS VIEWED ALONG ROLL AXIS (CENTER OF CIRCLE SHOWN IS ROLL AXIS WITH TOP OF SPACECRAFT POINTING OUT OF PAPER) LOGIC USED TO COMMAND SPACECRAFT MANEUVERS TO ACQUIRE SUN FROM SECONDARY SUN SENSOR CELL SIGNALS CELLS ILLUMINATED A D NONE A AND D B C B AND C A AND B C AND D COMMANDED MANEUVER "_ YAW * YAW ._ YAW ._ YAW - YAW - YAW - YAW ._ PITCH - PITCH FIGURE 13-2. SECONDARY SUN SENSOR ORIENTATION LOGIC 154 (star sensitivity swept parison before intensity) range out by between launch The for the is monitored. of sensor the the the Ganopus field positions particular is in in level before in the is not the of Thus sensor view stars launch a map and as on date the of all stars within having the is intensities 360-degree generated. on to a map be in the failing vehicle map permits to perform band A prepared com- rotates and those of this Ganopus in The a verified. environment Ganopus might be while sensor expected it is required Van Allen radiation is become such as belt. sensor and to expected operational correction to reference to be as is and inoperative soon not verify required as planned lockon for the radiation reduced. after to environment, Since launch, the the first it radiation to occur to the midcourse will be possible roll 8 hours time before acquire Ganopus maneuvers establish this spacecraft correction. Coast Phase 1 The ing with coast phases of the mission to the sun mode are and characterized to the star by Ganopus the spacecraft with the coast- its attitude on The servoed low-power transmitter tracking. with signal in the transponder transmitted power to permit radiated PGM continuous via two-way doppler antenna, at a rate as a coast will be on an omnidirectional engineering data processing with the equipment to provide consistent result phase signal-to-noise conditions. midcourse is operating gas ratio available Goast phase at the ground i occurs receiver and of these Z occurs Since the amount this of operating after, spacecraft of nitrogen the before, correction. under for greatest coast conditions the {typically to be used for for attitude 51 most of percent standard The For capability for a amount standard indiof the the misspacefor sion, craft the the during required the of coast maintaining portion expected attitude phase the total represents amount by on of the the gas is 3 ¢ case) nitrogen phase is to plus operations of nitrogen accomplished gas this in table carried quantity 13-Z with control 4.5 the system. pounds. spacecraft expected nominally provide a reserve mission, cated situations. nominal quantity a 3 0- probability nonstandard With sun and the spacecraft the locked solar mission on to the sun, the on solar panel will be facing the will For convert energy impinging for it into necessary phase, electrical space- power. craft the typical load sequence the transit which the total electrical is in excess of the power will be provided to the loads 155 TABLE 13-Z. COAST PHASE ATTITUDE CONTROL CAPABILITY Time/Number of Maneuver s 30 minutes Mode/Maneuver Rate-stabilized mode, including dissipation of separation rates Inertial hold hold) 1 hour, 50 minutes 65 hours 1 1 4 6 5 ;:" Optical mode (celestial Sun acquisition Star acquisition Star verification Roll maneuvers Yaw maneuvers _Maneuvers corrections. required under standard conditions for two midcourse by the solar being panel via the optimum continuously demand Thus, change by the regulator. spacecraft and the This battery power be situation to make being results up in power ence solar supplied the differby the time between panel the power (figure of the loads the battery supplied 13-3). will not fully charged at the of landing. Of the total electrical of spacecraft load indicated in figure 13-3, the power A and required compartment The indicated dissipation A At has a typical in figure of 17 steady comshaded sun. Thus, for B the operation must be within components capability in the within compartment compartments. the dissipation phase results phases, of these standard 13-4. watts transit During compartment B has dissipations a steady the coast compartment to 37 watts, peaks than with transient peaks with of up while of up compartment to 75 watts. B and dissipation partmentA during the of Z5 watts has coast more phase, transient area present, radiating while more compartment B is partially by the compartment energy in the than is fully illuminated B results 13-5. During during in the the it is able The the to dissipate power compartment this period. temperatures coast phase, of these dissipation trays as compartments in figure compartment indicated 156 Iooo LAUNCH EVENTS LAUNCH SHROUD EJECT}ON TO SUN T ACQUISITION MIDCOURSE OPERATIONS BY CENTAUR -/ / EVENTS : CORRECTION PRESEPARATION COMMANDED MANEUVERS VELOCITY CORRECT_ONOF SUN I TERMINAL EVENTS: PRERETRO START TV MANEUVERS DESCENT I INTERMITTENT 940---_ TRIGGERS IGNITION _ _ R I I I FRAMES RADAR ENGINE MARKING VERNIER RETRO VERNIER TOUCHDOWN goo -- SPACECRAFT DSIF ,SUN SEPARAT}ON ACQUISITION ACQUISITION I '_--_ COA ST PI'-IASE I _"_ f_'_- REACQUIStTION AND STAR ENGINE IGNITION DESCENT | -_ -_ --COAST SE If I I 3O0 S/NADR tECRQIU:SITION _ ;I_GGHNE E RDATANR_T NETERROGATIO N! A 2O0 O 0. IO0 CONTINUOUS LOW RATE TRANSMISSION DATA NOMINAL ELECTRICAL LOAD NOMINAL OCR OUTPUT UrNA_IRATTERYLOAD 0 LAUNCH Io 2o 30 TIME FROM LAUNCH, 40 HOURS 50 60 _ TOUCHDOWN 70 FIGURE 13-3. TYPICAL AND STANDARD TRANSIT POWER PROFILE OPERATIONS temperatures expected pha'ses are well within the estimated allowable upper limit during of IZ5°F. the coast The typical are shown the performance in table coast in any signal of other 13-3. the spacecraft equipment During data phases, spacecraft data can be-commanded (i,e., types to transmit commutator found on PCM continuously engineering are of the four processor. arrangements the modes) these of the modes Briefly, of data described below. 157 80 f-1 II I _-: ....... : 0 I:00 5:00 600 7:00 __._L __Jl__ ._ _ _ __ _ _ ___ ._.i JJ__ _ m -_ TYPICAL 01SSIF_ATION --COMF_RTM(NT A _IN_LU_tES O_R AND STEPPING MOTOR SWITCHES) -CO_PARTMI[NT B • 12:00 1300 1400 1500 TIME 1600' AFTER . 2T30 LAUNCH, 3930 HOuRs . 5230 5330 82:00 I 6300 I 6400 6500 66:00 FIGURE 13-4. TYPICAL DURING COMPARTMENT STANDARD TRANSIT THERMAL PHASE DISSIPATION Mode 1 This mode contains most primarily coast and thrust phase attitude data used and for control a few data. propul- It also sion contains of the telemetered This mode electrical is expected and current to be system temperatures. sun and monitoring correction. just the attitude maneuvers, be star acquisition, during midcourse velocity It will also before proper the of primary and attitude interest terminal control the high-data-rate since this data interrogation can verify midcourse of the maneuvers system. state Mode Z This mode appear used contains on mode the same coast phase and thrust phase attitude control since data which I; however, terminal the number when of signal the data samples is less via it is normally high-gain mode also during descent transmission to be used. the This planar array permits higher transmission the retro burning bit rates phase, includes and signals covering power. vernier system temperatures, electrical 158 140 T _COMPARTMENT _COMPARTMENT D COAST PHASE A B 120 TEMPERATURE -+5 ° AT _ w IE w 80 IOO "1"1_0 AT DStF TIME TOLERANCE ACQUISITION _ 20 HOURS 6O TO BE DETERMINED TEMPERATURE TOLERANCI [ J l TRANSIT PHASE "_--LUNAR PHASE--..--.----Ie_ I AND SUN ;TAR ACQUISITION VERIFICATION AND MIDCOURSE CORRECTION ACQUISITION 120 i:i:i:i:i:i:i:i:i:ii:i:i:i:i:i:ii:!: nW_ ::::::::::::::::::::::::::::::::::::: 80 4O CD o -4 0 4 TIME 12 AFTER LAUNCH., HOURS 20 !iiiii_iiiilililiiiiiiiiiiiiiiiiiiiii_iiiiiiiiililiiii!iiiii! 60 65 0 66 I TIME 2 AFTER 3 4 TOUCHDOWN, 5 6 HOURS FIGURE Mode 3 This for 13-5. COMPARTMENTS AAND B TEMPERATURE PROFILES mode contains the vernier data and the signals descent altitude used for lunar This reflectivity data measurements by and monitoring (RADVS) 4 This mode sequence. control signals. is provided the doppler radar Mode contains and the data primarily link panel spacecraft electrical power, thermal in the DSIF and mechaacquisi- nism tions status positioning, to position during the signals. and It is intended the for use solar monitor spacecraft power thermal mission. 159 TABLE 13-3. TYPICAL EXPECTED THERMAL DURING TRANSIT Transit Temperatures PERFORMANCE (°F) Touchdown Coast Phase (Maximum Eclipse I/Z hour) Survival Temperature Limits Subsystem Vernier tem* Painted pellant Blanketed propellant tanks Thrust chambers Plane valving Barrel/ extension cone Propellant transport line s Heated length Aluminized length Helium tank at Operating Temperature Limits Prelaunch Temperature Acquisition (Maximum Eclipse 1 hour) sys60 i00 80 to 90 ZO to 60 to 34 to I00 protanks 0 to I00 80 to 90 50 to 85 0 to I00 0 to I00 80 to 90 55 to 90 60 I00 to 35 to I00 0 to I00 80 to 90 45 to 90 ZO to 60 0 to 60 0 to I00 80 to 90 I0 to 50 I0 to 50 I0 to 50 0 to I00 80 to 90 30 to 90 50 I00 to 0 to IOG 0 to I00 80 to 90 Z0 to 90 55 to I00 Z5 to 10C *Temperatures system listed under touchdown refer to a time to those temperatures at time 6 minutes of before activation which correspond of approximately touchdown. 160 TABLE 13-3. TYPICAL EXPECTED THERMAL DURING TRANSIT (Cont) Transit Temperatures Acquisition (Maximum Eclipse i hour) PERFORMANCE (°F) Touchdown Coast Phase (Maximum Eclipse i / Z hour) Survival Temper-' ature Limits Subsystem RADVS system ;',_ Signal data Ope rating Temperatur e Limits P r e iaunc h Temperature -40 257 -40 to 41 to 77 100 imum) (max- 38 80 to 33 to 85 converter Klystron power ply Velocity sensing tenna Altimeter velocity sensing tenna Shock sorber Main retro abanansup- to -22 14 to i00 imum) (max- - 24 16 to -26 to 18 257 - 90 220 to - 90 220 to 100 imum) (max- -123 253 to -131 to 261 - 90 ZZO to -90 220 to i00 imum) (max- -123 253 to -135 to 265 -50 300 20 105 to Z0 to 1Z5 85 (mini- 0to 15 80 120 to 15 to 125 mum) to to Z0 75 80 to 90 70 to 90 32 to 85 17 toTO propellant (30 hours after launc h) Solar panel -3Z0 235 *Temperatures system listed under to - ZOO 145 touchdown refer to a time to those to 80 to 90 -ZOO to 140 117 140 to - 140 to 140 temperatures at time 6 minutes of before activation which correspond of approximately to uc hdo wn. 161 TABLE 13-3. TYPICAL EXPECTED THERMAL DURING TRANSIT (Cont) Transit Temperature PERFORMANCE s ('F) Touchdown Coast Phase -166 -I00 to (Maximum Eclipse 1/Z hour) -234 to Z58 Survival Temperatu r e Limits -3Z0 300 systo Subsystem Planar antenna Nitrogen tem Jets array Operating Temperature Limits -255 Z75 to Prelaunch Temperature 80 to 90 Acquisition (Maximum Eclipse 1 hour) -Z53 to 150 -30 160 to -30 160 to 80 to 90 I00 160 30 ii0 to T ank -70 IZ5 to -70 125 to 80 to 90 to Spac line s Leg eframe -160 to -160 to 80 to 90 90 lines -50 Z50 to 90 -50 Z50 under touchdown refer to a time to those to 80 to 90 150 Z50 to ,:,Temperatures system listed temperatures at time 6 minutes of before activation which correspond of approximately touchdown. Any rates: must be of these 1100, modes 550, on can be transmitted or 17.Z bits at any per of the available The choice spacecraft of the at the bit rate DSIF 4400, 137.5, the basis second. of the determined of the strength received signal station. Because the transmitter (low power) the of losses power and in cabling available I0 watts minimum are and tolerances on the transmitter the nominal output. As the power I00 Table shown, coast output, milli13-4 at phases. at the antenna (high power expected power) varies at the from watts transmitter antenna. during indicates least 24 expected available to be at the available milliwatts of power 162 TABLE 13-4. POWER INTO ANTENNAS Range of Values Nominal 45 milliwatt s Typical Operational Low-power omnidirectional Low-power planar array transmitter, antenna transmitter, 4.06 watts 2.69 watts Mode transmitter, antenna transmitter, 36.2 milliwatts Minimum 24 milliwatts 58.8 milliwatts High-power omnidirectional High-power planar array 4. 5 watts 5.88 watts Based DSIF System upon the DSIF system parameters dated in table documented 29 July 13-5. 1963, in Surveyor the expected Spacecraft/ quality of Interface data obtained Requirements is indicated telemetry Midcourse The sufficient primary As eters, Correction soft landing time goal a to obtain Maneuver of the Surveyor lunar data spacecraft via the Goldstone at a desired DSIF lunar location station with is the tracking of a Surveyor of expected mission. dispersions in the launch be required vehicle injection the paramspacecraft miss from result a midcourse The correction purpose spot will normally to correct the trajectory. the desired and to adjust of the correction on the moon, time is to minimize expected of landing the to optimize the probability soft landing, from the spacecraft station of flight so during that the desired and subsequent to the visibility to landing. Goldstone tracking is achieved increment In general, correction so-called the velocity of two and applied The primarily spacecraft to effect will be The the will consist critical plane components. first component for the miss. in the will correct second 163 TABLE 13-5. Data PCM (at lunar distance) Accelerometer channels (Transmitted during retro burning) EXPECTED QUALITY OF TELEMETRY Signal-to-Noise 8 +l db (rms signal at input Ratio to to r Re sulting Bit error Quality rate of rms noise) approx. 3 x 10 -3 subcarrier >46 rms db (Peak disc riminato signal at output discriminaproducing of the to of <0. 5 percent due to noise) distortion noise subcarrier tor for peak subcar signal deviation rie r (rms noise Touchdown Strain Gage Channels Z0 db rms signal at output to of i0 percent tortion noise due disto subcarrier tor for peak disc riminaproducing of the signal deviation subcarrier) TV Z4 (Peak-to-peak noise level of signal to rms ance at lumin100 foot Lamberts) component following a. will be normal soft The landing main and retro to the critical plane and will be sized to optimize the time-of-arrival burnout velocity constraints: must be between and limits imposed radars by and the the operational mechanized b. A sufficient ranges of the doppler velocity altimeter range/range-rate amount of vernier control thrust The for as the can can descent fuel must be be exerted curve. be reserved to ensure retro that the phase during of the termito ensure required and moment during the main until fuel and be that the desired descent. used (defined maintained of reserved correction must touchdown in excess the nominal enough the vernier amount nal quantity midcourse to be descent the fuel margin) large 164 that a s o f t landing c a n b e accomplished f o r the 30- v a r i a t i o n s in specific i m p u l s e , burnout velocity, and a l t i t u d e , e t c . c. The incidence angle of the unbraked velocity m u s t be l e s s than s o m e maximum value (nominally 4 5 d e g r e e s ) to e n s u r e that the m a r k i n g r a d a r will operate properly. This c o n s t r a i n t will a u t o m a t i c a l l y be s a t i s f i e d b y s e l e c t i n g the landing s i t e p r o p e r l y (figure 13-6). FIGURE 13-6. POSSIBLE LANDING SITES 165 d. The time at which the spacecraft arrives at the moon must be earlier than a minimum allowable time (nominally 3 hours) before the last lunar visibility at Goldstone to ensure that there is sufficient visibility at Goldstone can be time to so that conduct TV surveys after touchdown. than nominally Z hours after the first the command from The because The actual Goldstone. midcourse velocity in the desired correction and execution of the This time must also be later descent accomplished terminal may differ and been from that desired control systems. Specifi- of uncertainties in the spacecraft landing attitude has velocity uncertainty 30240D, the limits location Design specified " and in JPL this, cation sets "Surveyor on 13-7 the Spacecraft Specification, errors. at the moon in turn, midcourse mechanization miss A Figure of the cuted shows the estimated magnitude. results 15 minutes these assumed (99 percent) as a function exeif the midcourse 15 hours correction after injection within for 30-meter-per-second in a miss the start of 47 maneuver kilometers typically after correction maneuver. miss is applied Therefore, of the initial pre-midcourse (which are typical), the conditions illustrates is within 60 kilometers. This figure that for a given correction, 160 (n nr w Fw O .J GYRO DRIFT TIME I : 15 rain RADIUS ON OF OF CIRCULAR MISS DISPERSION 990/0 EXECUTION OF LUNAR SURFACE ALL POSSIBLE CONTAINING MIDCOURSE AS FUNCTION MAGNITUDE 120 -- i ERRORS IS MIDCOURSE PLOTTED MANEUVER 8 b80 TIME {n o3 OF CORRECTION '20 hr$ AFTER INJECTION (20 hr MANEUVER NOT PLANNED-SEE TEXT) 15 hrs 40 AFTER INJECT__ i bZ tu (.) _r W 0. 30 MIDCOURSE VELOCITY INCREMENT, 60 METERS PER SECOND 90 FIGURE 13-7. MANEUVER TYPICAL MISS MAGNITUDE AS FUNCTION FOR NORMAL OF MIDCOURSE IMPACT 166 the (e.g., expected Z0 hours error will versus decrease 15 with hours) time. if the correction the sensitivity for be larger for be since the is applied of same for the at a later time to a given of at in Goldstone no longer 20 since However, miss will trajectory the correction correction hours 1965 tracking be visible than and decreases required one 1966, station from applied reason, a correction ascent from amount applied for at a given 15 hours. Further, cannot direct commanded the trajectories the will a midcourse at 20 hours maneuver after injection, spacecraft Goldstone. The amount ing the maximum midcourse be correction for that can be executed depends without on the of fuel ability that can of the allotted the midcourse correction jeopardizthe space- spacecraft with to achieve vernier and terminal a soft landing. fuel to permit Typically, up to a 30 craft second will be loaded sufficient accomplished during meter-perthat impact correction to be to ensure descent a 99-percent for a nominal up to 45 probability unbraked degrees The 30 (See sufficient velocity Appendix mum second time For of fuel is available Z690 item meters 5) and correction B, per second, incidence time angles B, a nominal of flight of 66 exceed hours. actual maxi- midcourse (See capability item 3) value could on the nominal depending meter-peron the actual Appendix any mission, and of flight, example, the unbraked figure available 13-8 for incidence illustrates midcourse burnout angle, the unbraked relationship and for a impact between velocity. the amount velocity and the typical correction velocities on of propellant for various the unbraked specific time impact fuel margins incidence of impact correction descent of Z686 until B). the fuel and the Clearly, actual of for Z670 fuel angle. and of flight which unbraked as for a function midcourse Also .indicated the amount satisfy of per burnout of all this figure of propellant constraint For midcourse is is a curve the of depicts, can use velocity, and 99 still percent meters margin the unbraked the for time all of spacecraft the cases. reserving for sufficient impact can straight is a be used terminal velocities in lines function is also each A example, propellant reached second, velocity allowable velocity. and but incidence case and of (follow correction midcourse there is no amount impact flight midcourse Since the angle, capability specific will a function capability for To each maximum exist missions, on a particular parameters. maneuver, maximum capability mission, depending mission perform to point a midcourse in the proper correction inertial the spacecraft must be com- manded direction arid to operate its vernier engine 167 8o I 6O 8O o z I SPACECRAFT VERNIER VERNIER WEIGHT ENGINE ENGINE 2100 149 Ib Ib FUEL Isp 300 sec MAIN RETRO BURNOUT FUEL VELOCITY MARGIN 8 6O - /7"- zo V '>'. " /\ / './ 'y \/ ' ,5o z w z >- ,Cd 2O ,///.,/.Z (z 8 r_ /'/7 POST ./,, z / / \>,\ ,%dT,o '_£TMot;:E:E,=_ 7 X/';' I 2660 MANEUVER IMPACT 2600 2630 MIDCOURSE 2690 VELOCITY, METERS PER 2720 SECOND 2 rSO FIGURE 13-8. TYPICAL MIDCOURSE MANEUVER CAPABILITY system maneuver engine for to achieve the required the vehicle the velocity correction. so The first step axis in this of the vernier direction provides All of multiple used to the is to orient system (i.e., angularly Z-axis) coast phase that the thrust with control pitch, spacecraft The is aligned attitude in yaw, rate one the desired the velocity for correction. maneuvering are system and roll. and method capability these angular command any one in either direction maneuvers maneuvers the of the performed performed to make is as about at a nominal serially, an angular the for of 0.5 deg/sec, The are at a time. spacecraft three axes change of a desired magnitude about follows: that axis spacecraft the specific is commanded time rate interval to maneuver required for in the desired it to maneuver A taining direction through the desired angle by at the fixed sending of 0. 5 deg/sec. command This con- maneuver the 10-bit sequence binary is initiated a quantitative maneuver equivalent of the desired duration. 168 magnitude and with is also the is stored transmitted in a register back by the spacecraft receiver flight control where When it may programmer, be compared that the to to the ground from magnitude has the commanded the ground. magnitude, or two it is verified then be commanded spacecraft execute received the proper it can yaw) desired maneuver programmer (roll, pitch, contains in the proper rates which direction. permit it to The count spacecraft clock the number rate of seconds provided Thus, stored in the programmer. storage angular For attitude maneuvers, register com- the clock is 409.6 manded 204.8 is such the that the nominal maximum by single capability change of the be seconds. and that can controlled Larger the two automatically single angular time the spacecraft maneuvers the earth. or roll-yaw) There can programmer be executed is nominally only by manu- degrees, ally controlling Normally, spacecraft storage magnitude serially. The plished commanded the thrust before maneuver maneuvers from (roll-pitch are required to orient command the applyin_ aboard midcourse the thrust. and is no multiple can be capability spacecraft, these the programmer must only store one at a time. Consequently, maneuvers accomplished velocity correction similar for by applied during for the midcourse the maneuvers. As sequence The is accomis in a manner to thrust is provided a constant magnitude to that used period vernier spacecraft in table a desired the three of time. engines indicated the g for 13-6, to to cause spacecraft experience time. verified The acceleration of the desired similar of nominally thrust time 0. II earth is sent the the commanded and to the maneuver spacecraft time flight in a manner case to that used correction, to verify the rate magnitudes. control storage to In the programmer capacity provide At control The the of the velocity rate second is such available clock of the is employed. nominally of up This that the maximum time is sufficient register is 51. Z seconds. to 55 meters for per the This second. a nominal the end velocity of the commanded provides can also be time the cutoff midcourse for shutting thrusting, the flight engines. situtation, programmer signal signal from off the vernier abnormal cutoff commanded earth if, in an programmer should fail to provide this signal. 169 TABLE 13-6. Operational Midcour se velocity correction Mode VERNIER ENGINE THRUST CONTROL MODES Desc ription of Mechanization Vernier engine thrust servoed to provide a fixed vehicle acceleration for the commanded time interval. The vernier engines are throttled differentially to correct for main retro thrust misalignment. Two commandable thrust values (ZOOand 150 ibs) are available. However, the flight control electronics will override these values when the main retro misalignment requires compensation thrust from the vernier engines different from these values. Phase of Mission When Utilized Midcourse maneuver Main retro Retro burn period Main retro separation Constant total vernier thrust Retro separation of near maximum value (typically >Z80 pounds) is provided for an interval controlled automatically by the flight control programmer. Thrust to mass ratio maintained constant at nominally 0.9 lunar g. Vernier descent Vernier descent Acc ele ration control Velocity control by range reference Thrust is controlled by the doppler radar signals to approximate an optimum (minimum fuel consumption) descent trajectory. 170 TABLE 13-6. Operational Constant control Mode velocity VERNIER ENGINE THRUST CONTROL MODES (Cont) Description Thrust constant nominally of Mechanization so that a of Phase When Final descent of Mission Utilized vernier is controlled spacecraft velocity 5 fps is obtained. Coast Phase Following 2 execution of the midcourse the sun and star, velocity thereby for the correction, returning reacquisition of the the the spacecraft is commanded optical to be those in the star as to reacquire control mode. spacecraft sun and to the star as and and It will be either by possible of the same accomplished performed reverse it did (i) performing maneuvers but magnitude direction the sun before order, or the midcourse (2) by sun thrusting, the in the opposite to acquire commanding and star spacecraft in the original acquisition. Pre-Terminal Descent Planar Array The Positioning planar result The array antenna is stepped by after earth commands to the maneuvers commands, high-gain that will position are with in its pointing to the earth the pre-retro by ground performed. each command stepping resulting of the antenna in a i/8-degree the planar maneuvers is accomplished step. array so positioning amount It is desirable execution which reducing completed. ily as the of the system the number The to accomplish descent prior to the during terminal is placed of TV that the is kept taken must and of time in the inertial pictures mode be to a minimum after be without are primarbetween that can the maneuvers changes to vary angle of the to which unbraked 68 degrees the array the planar incidence for would array angle, stepped a function 38 is expected of ±45 approximately (For vertical and incidence have ) angles degrees off vertical. 5Z degrees, impact, to be stepped approximately involving At (nominally angle approximately 48.5 degrees, 416 commands. array cone) array the planar half-angle the planar will begin of the Canopus to obscure sensor a cone the field of view sun channel. At an a 5-degree degrees, of 68 will permit only of approximately 171 0. 75 degree half-angle clear field of view. With a restricted field of view, the Canopus sensor may loose the sun reference, resulting in the roll attitude of the spacecraft reverting to the inertial mode. The approximate time required to step from 48 to 68 degrees is 80 seconds, and the amount of time required to send and verify the commands required to initiate the first roll maneuver is estimated to be approximately 155 seconds. Thus the system could be on inertial for almost 4 minutes in addition to the presently planned time if the complete stepping sequence were accomplished for a mission where 68 degrees of stepping were required. It may be necessary to step the array out in two sequences. The array could first be stepped out to an angle which would ensure no shadowing of the Canopus sun channel (e.g., 45 degrees) before the maneuvers are performed. Then, any additional stepping that is required in excess of the initial stepping could be accomplished subsequent to the maneuvers. The time required for this additional stepping (a maximum of 9Z seconds) could reduce the time available for obtaining approach TV pictures prior to retro-rocket Maneuvers Before are performed. the retro-thrusting The (nominally main (a retro-engine roll) causes descent a roll period, sequence and a pitch is or with array bandwidth missions PCM are can A to the on the thrust where and obtained. be accomplished in command and from by the proper spacecraft gas jets the same representing receipt of telemetry. at a nominal manner the this as to three shown yaw the point spacecraft in figure maneuvers 1-3. align vector. the earth for lighting the so The the The that normally first thrust last the necesof permit) the two axis ignition. maneuvers of the maneuver) velocity to approximately the planar maneuver sary approach and high-rate telecommunication TV pictures (4400 and Each of retro these bits burning three (for information those per required lunar accelerometer transmission conditions second) phases data during pre-retro maneuvers maneuvers. is is sent verified by the midcourse maneuver by the correction duration spacecraft is of 0.5 then quantitative spacecraft, the ground provided desired command The angular maneuver rate executed deg/sec. 172 Approach The approach the last the time The miles first from Since transmitting mutator TeLevision spacecraft TV camera can be commanded interval to take between the up to I00 that array TV the pictures spacecraft with the in the time executes and sequence. than I000 roll maneuver that the pictures to point marking taken the high-gain radar when the planar toward the retro the earth ignition no less altitude will be signal initiates spacecraft is at a range the lunar the present TV video the These surface. design signals picture blocks of the spacecraft does with will be will be status are picture PCM not provide data capability of simultaneously sequencing of pictures of one normally of the comconsisting in which be moni- modes, TV in blocks of l0 pictures. engineering tored, will be predicted but not data separated of the being by periods can is telemetered when necessary so that the commands last TV spacecraft sent. as The particularly commanded time so close spacecraft to the to occur, can verify taken surface. of taken to transmit at which as the at a time trigger of PCM close the altitude-marking-radar the transmission It is estimated range is expected data which to jeopardize that this trigger before retro The the at approach 1000 miles by signal is generated. that the last picture miles 13-9. from The the lunar ignition will be TV at a nominal is shown 6.4 of 80 approach TV geometry in figure by 6.4 field of view camera is nominally than 180 degrees on each so that a picture side. impact The will be greater kilometers coverage The smear control provided pictures because system the field of view in the pre-retro angular rates is a function period are of the unbraked expected while to have angle. taken of the a negligible attitude of the vehicle the cold gas is still controlling In addition the vehicle attitude. it may be possible Any because and to obtain pictures of the are also a few during of to to the pre-retro when phase the pictures, sequence additional the the have Also, retro main pictures burning landing permits. taken effects will be and TV subject to degradation exhaust because and gases gases retro-engine vernier lines engine of smear retro expected thrusting. subject to have a minimum any picture caused lines of five taken by of effects separation and of retro will be between vernier burnout exhaust to one degradation to four TV engine is expected of smear. 173 OFFSET ANGLE AT I000 mi .0 OF VIEW 5.4 deo vELOCITY VECTOR AT RETRO RETRO ALTITUDE 3UMERA AXiS AT IO00 mi SLANT RANGE LANDING SITE LUNAR SURFACE FIGURE 13-9. APPROACH TELEVISION GEOMETRY It will probably when the spacecraft be pointing those not be possible to obtain TV pictures control after since retro the separation array attitude is switched to doppler planar will not to the earth. resulting by the amount is set by can by be in night moon landings during as well or as some day terminal can landings, For the launches will be The spacecraft phase. shaded part all of the the descent be shaded maximum of time two during which spacecraft during that the is limited this phase spacecraft primarily not installed phase different on inertial amount controlled may be drift considerations: hold (i.e., (I) the amount relinquish and sun of time lockon) craft on The the placed the expected of gyro drift, (Z) spacedepend equipment spacecraft in thermally orientation compartments and become 30 which coast damaged inoperative. Coinis limitation attributable to allowable due to thermal gyro is nominally minutes. equipment cidentally, the constraint limitations of spacecraft 174 also approximately 30 minutes. Table 13-7 shows the spacecraft equipment whose performance would be affected by being shaded during the terminal descent phase. This includes the vernier system, flight control system, landing leg shock absorbers, signal data and the solar and panel. the The most critical items are the doppler radar converter shock absorbers. Lunar Approach To reduce Altitude Measurements of false alarm, the altitude slant (Z615 marking of IZ0 radar ±45 will miles. the probability until the not be enabled For spacecraft of impact is at a nominal velocities range the design range to Z69Z before latest assuming meters/second), the radar marks time) the to the number will nominally 257 of measurements v_ry from 36 and provided (for highest earliest in the interval velocity and enabling that marking (for lowest exceeds velocity the agc enabling time), that received radar is signal enabled. threshold at the time the altitude Measurements descent the four ments phase doppler by of lunar measuring radar beams. descent, reflectivity the received There assuming can also be obtained of the be during radar the vernier in signal should that strength return nominally the radars a total of 5Z0 locked on measure- during vernier are at the time of burnout. Terminal The and Descent terminal descent phase comprises main retro descent, vernier descent, touchdown. TABLE 13-7. MAXIMUM SHADE TIME FOR SPACECRAFT Maximum Time EQUIPMENT Allowable in Shade hours) Spacecraft Vernier RADVS Helium Shock Solar engines signal gas Equipment (3) data converter (approximate 0.8 0.5 0.8 0.5 0.8 supply (3) absorbers panel 175 Main Retro The Descent events The that constitute sequence radar when surface, After expected are the automatic by retro sequence signal are illustrated by the of 60 in figure 13-10. is initiated the the trigger is nominally provided altitude-marking miles from spacecraft at a slant by range the lunar and is controlled delay and main automatically and the flight conwell in trol programmer. advance of the a prescribed marking ignited. engine is turned time The (commanded verified stored retro in the flight control engine is ignited After programmer), a 1 second delay of the vernier delay 0. 55 engines after to permit second, the vernier the RADVS thrust on. to stabilize. a further i o W d t.) O 4 p- _A 1.) i TIME (NOT TO SCALE) FIGURE 13-I0. TYPICAL RETRO SEQUENCE OF EVENTS 176 The total thrust provided by the vernier engines during the retro burning phase can be commanded in advance of the retro period to one of two values, typically 150 or ZOOpounds. The lower level is provided for use on those trajectories where the impact (lunar approach) velocity is low and hence the burnout velocity will be low. By reducing the vernier thrust, the burnout velocity can be increased to a more acceptable value. The descent trajectory design is based on the assumption that the doppler velocity and altitude radars cannot be used reliably while the main retro-engine is burning. Thus, the spacecraft attitude will be controlled so that the attitude will remain fixed inertially throughout the retro phase. The main function of the vernier necessary controlled engines during this period is to provide the moment to accomplish this control. Where possible they will also be to maintain the total vernier thrust at a constant (i.e., 150 or ZOO pounds) value. The thrust phase attitude control system is mechanized so that the moment demand overrides the thrust level command when the two are not compatible. Moment vernier engine engines can The pounds As and be control about swiveled about the roll axis is provided by swiveling one of the The a radial line perpendicular ±5.5 by to the vehicle roll axis. approximately provided removal degrees. retro-engine of the incoming by an is nominally spacecraft inertia 9000 velocity. switch. 3.5 sepaThe g average results burns when thrust in the out, the the main of the bulk in thrust acceleration control the grain senses the decrease spacecraft is sensed has switch and decreased to nominally the retro provides a signal This to the flight signal programmer to initiate engine thrust spacecraft ration sequence. results in the vernier level at the so level being increased experiencing the to the maximum the maximum In addition, delay programmed deceleration that the will be thereby down. aiding After time timer the of separation, begins main to count retro causing separation. time the flight control duration a fixed of sufficient the blown to allow delivers thrust the to reduce to a negligible separation The sufficient signal from nuts value, to be programmer apart. a signal retro flight control to permit permits the programmer retro-engine spacecraft velocity continues to clear pitch and to count the yaw down and, after a delay arming spacecraft, attitude the doppler provides control to be an which inertial the switched to doppler reference when velocity reliable 177 signal signal is is generated. generated, If this signal will be is already switched present immediately at the to time doppler that the control. arming control Burnout The by the Conditions spacecraft retro level for As velocity and altitude the at burnout are velocity and the determined at main primarily retro ignition, the the main thrust ignition altitude, by the main spacecraft provided retro-engine and burnout increment the vernier weight engines, at retro sum duration ignition. which shown this thrust in figure velocity, gravity retro is provided, 13-11, the spacecraft velocity is the from vector of the retro initial spacecraft phase, and Since mately applied retro the velocity resulting the main the lunar the main term. phase velocity by increment the main is supplied retro and to an vernier at the approxiengines) time of main is a constant total impulse nearly (provided opposite value in a direction ignition, to the spacecraft retro spacecraft velocity the absolute only of the main of the phase velocity start increment of terminal function primarily of the weight at the MAIN RETRO PHASE VELOCITY GLE, 8 INCREMENT, _V VELOCITY AT IGNITION, GRAVITY TERM t b qm t b : DURATION OF MAIN RETRO BURN BURNOUT VELOCITY, _b qm: ACCELERATION TO MOON DUE FIGURE 13-Ii. DETERMINATION OF MAIN RETRO BURNOUT VELOCITY 178 descent. course determined primarily midcourse. figure This correction. by weight is Since determined the spacecraft impact the unbraked by the amount at of fuel retro the and used ignition burnout the fuel in making is the mid- velocity velocity impact vector, velocity occurs essentially is thus at shown in the unbraked of retro velocity consumed locus a function Main 13-12. The main descent spacecraft 13-12. If the main engines landing there Along values Control of This retro burnout nominally on the burnout burnout phase to follow which constraints follow. optimum to at a point are During determined this phase, by the it is requirements desired to indicated decelerathrust the too effect a curve, far soft of conin the trol figure tion. the and the vernier the the slant-range-velocity a gravity below to other supply locus, amount the vernier of return hand, of turn the the if with curve, spacecraft burnout fuel contour a constant maximum to occurs to curve retro will will corresponds burns not result. be out of vernier a hard curve, sufficient On the above will with of the and not the be an adequate burnout and during vernier landing. different nominal velocity typical midcourse phases the These operate 3 _ dispersion fuel is used ellipses are shown. by must are also accuracy altimeter must should by vertical together the for impact spacecraft altitude ranges The than doppler accomplished conditions the be shown at will funcbe doppler within in figure the velocity operational 13-12. greater at the radars. of these Therefore sensors. will 700 fps. not In burnout constraints within the the desired radar velocities not tion below ment velocity assumption burning. the ratio that a lunar in the certain the function before these that nominally above descent'curve The which not minimum the exceed cannot 850 addition, Since the burnout doppler radars velocity is with the set velocities vernier fps is (nominal). reached, these burnout velocity values. the angles must that The surface doppler the former and allowable roll 75 used requireand with the the is spacecraft 45 and be axis makes vector degrees, reliably that the a respectively, while three the doppler high from beams can be main radars retro-engine beams intercept restriction guarantees channels. The along so retro is that ensures that there latter at the burnout. with degrees the of least is sufficiently arises the roll doppler axis signal-to-noise the be aligned requirement greater with the than restriction one of velocity minimum vector component value following spacecraft velocity Since velocity must the roll also axis be aligned 45 velocity the vertical vector and at 75 burnout, degrees the of the burnout roll within 179 6O / I I 5O DOPPLER LIMIT "_" NOMINAL BURNOUT LOCus I I I I I I 99% DISPERSION ELLIPSE NO MIDCOURSE CORRECTION 4O ALTIMETER LIMIT FOR / / / _ _ / _( / / /\ f _ MAX,MO. M,DCOORSE / 99% DISPERSION ELLIPSE FOR / / --" / \' \ \ / CORRECT,O._ \ _ / ,/ z (I 3O / / Ii F- I \\1 / /x\ \_ ii / 2O i I\\ \ DOPPLER / / / / /COMMAND DESCENT TRAJECTORY 4 VELOCITY, HUNDREDS OF FEET 6 PER SECOND 8 I0 FIGURE 13-1Z. VERNIER DESCENT PHASE 180 axis at burnout. can be The minimum by nominal proper descent unbraked burnout choice 6 = 0). impact nominal and greatest velocity consistent offset with angle the above for the constraint main retro minimized of the thrust This yields and thrust (for vertical the lowest The impact a nominal smallest for burnout spacecraft the combinamust velocity be is velocity weight of 270 at retro fps for speed burnout ignition. unbraked 700-fps maximum speed velocity tion of highest chosen typically spacecraft This weight so that the 525 fps. constraint is not violated. nominal Vernier Descent Following the separation reliable of the (range main retro-engine range-rate) engine from the spacecraft and reaching and the before optimum obtaining descent radar curve and/or signals thrust (fuel-wise), ratio the vernier equivalent is servoed 0.9 lunar g. to mainIf the is tain a constant doppler switched by velocity thrust-to-mass reliable signal velocity to nominally and yaw is present, reference, the pitch and attitude attitude control to the doppler the vehicle to the vehicle is controlled (V x and Vy) servoing zero. When the components of velocity normal roll axis toward the optimum descent down i000 trajectory the desired feet, curve is reached, the thrust is concurve. to trolled At an to bring altitude the the vehicle of nominally factor is 5 fps to the preprogrammed altimeter At range-velocity will provide the radar system. a signal change the scale control of the doppler a velocity reference. and of nominally A constant 10 fps, velocis thrust switched is then inertial to the doppler commanded, hold mode. phase to be the velocity and ity of nominally switched back the pitch yaw attitude control During permitting ing the the vernier spacecraft descent spacecraft and will transmit providing data PCM for data, determin- operations monitored lunar reflectivity. the shut spacecraft reaches an by altitude a signal stirring of nominally from up the a dust radar cloud 14 feet, the vernier to mini- When engines mize the are off automatically of the altimeter at landing. possibility spacecraft T o uc hdo wn With remaining the vernier engine lunar system surface. cut off, the As the spacecraft will free-fall touches the the 13 feet to the spacecraft surface, 181 the tripod landing gear system (with the spring-damper legs) provides stability and, in conjunction with the crushable blocks on the spacecraft body, helps to absorb the kinetic energy of the landing. The spacecraft is designed so that it will not topple on landing (i. e., will settle in an upright position) on the assumed lunar terrain when (1) the vertical velocity is Z0 fps or less (See Appendix B, item 4) (2) the limits of lateral velocity are as shown in figure 13-13, and (3) the centerof-gravity location (shown in figure 13-14) is not exceeded. These limits are based on a vehicle radius of gyration of 3Z inches or less. Lunar operations will not be impaired by the structural loads imposed under the conditions indicated in figure 13-13 within the landed weight range of figure 13-14, provided (I) the vertical center of gravity is not below spacecraft station 63.48 and (Z) the vehicle radius of gyration is 28 inches or more, under the same vertical velocity, slope, and friction The terrain coefficient noted below. terrain at the landing as: (I) a slope site is unknown. not exceeding strength and Surface proper The assumed nature of the lunar at the landing site is defined or less, 15 degrees, from 50 to of fricare of the strength (2) protuberances 25,000 psi I0 cm (3) terrain and design compressive purposes), 0 to 1.0. to ensure (for landing landing dynamics (4) coefficient dust tion with uncertain, spacecraft may be the gear foot pads means of from provided conditions but and reasonable components from are functioning in the presence but is not of dust. included Surface in the compressive design different that noted requirements. LUNAR PHASE Postlanding The descent The ments high Engineering initial period subsystems power Sequence after and landing will be not utilized required the to turn during off all terminal lunar operations. compartwhen phase functions electrical dissipation will lunar within require noon thermally controlled during a normal occurs under landing near immediate conditions. turn-off, Engineering particularly data the landing sions by transmis- to verify the spacecraft response antennas to be to turn-off with turned the commands spacecraft will be accomplished in the flight and be means of the omnidirectional mode. power; line, The functions transmitter RADVS power; high-power control vernier off include: and approach fuel, and television oxidizer camera thermal 4 power control. temperature Commands control; will then tank 182 'I5 SPACECRAFT WEIGHT = 59_) TO 7i_ lb VERT1CAL VELOCITY' __ 20 fps A cg = BETWEEN SPACECRAFT STATIONS 63.48 AN{) 66,48 RADIUS OF GYR_.TION ; 28 T0 _2 ;n FRICTION COEFFICIENT __ 1.0 z O (...) LIJ u') n,.u.J Q. I-I,.i.I I.,i,J LI.,. 10 SLOPE _>I_) deg 1 >.F-,(O O _1 ill > n." I-,J I./J _J nn O .J ._J <_ :3 -5 ',-.,-,....__._... X -tO -5 TOUCHDOWN 0 INCIDENCE 5 ANGLE, DEGREES tO t5 FIGURE 13-13. MAXIMUM OF ALLOWABLE TOUCHDOWN LATERAL INCIDENCE VELOCITY ANGLE AS FUNCTION 183 69 f, SHOCK ABSORBER 6e TEMPERATURE "TOUCHDOWN, AT OF = 20 40 6O 70 8O I00 I20, 66 oLD U_ 0 n_ W Z tu o ,_1 65 ALLOWABLE LANDED MINIMUM WEIGHT I12: IJJ 64 550 600 LANDED VEHICLE 650 WEIGHT, 700 POUNDS 750 FIGURE 13-14. MAXIMUM AS ALLOWABLE FUNCTION OF VERTICAL LANDED WEIGHT CENTER OF GRAVITY 184 transmitted operations The ducted to lock are the landing to be of the gears completed spacecraft design, and dump helium. In a typical 4 minutes. landing shock data may case, these expected in approximately survival and of the assessment will be for con- to acquire reliability, The functions array subsystem of touchdown of the operating survival second postlanding operational verification nal planning. of such assessment as and include sigoutput thermal operation solar and panel transmitter, solar panel of the processing, spacecraft system The extent planar positioning, and power, control temperatures electrical the on the condition system. assessment response and power to which postlanding solar lighting of the spacecraft is possible time landing or desirable is dependent after the be touchdown, solar conditions, Goldstone requirements. visibility A survey night remaining will which noon and payload operational (as well acquisition as preclude must landing for panel assessment earth that of the the television, antenna). A delayed reduce un_til after the extent with high-gain by may of assessment because possible restricting the time available encountered Goldstone craft continuous at that time. operation of the high with of the spacecraft minimum temperatures of 3 hours of If touchdown occurs the visibility remaining, se, may as the evaluation opposed relative importance of spacedata by assessment per station, to the acquisition for the optimum of initial scientific allocation the Goldstone time. be desirable of available The be postlanding for positioning day landings for of the and solar panel and planar for night array antenna will The teleof landing, sun accomplished is also desirable landings. necessary positioning communication power for is required bandwidth lunar day the case for of day landings to assure and for the television and solar the and transmissions charging. to face the generation of a night morning operations the battery panel earth time and, In the case it is .desirable and the planar The to position array the direction wide-band for the of the to acquire utilized to provide required telemetery capadepend noon, at conductwill be bility. on on procedures environmental initial positioning occurs near lunar the lunar the conditions controlled acquisition the planar if the landing spacecraft The thermally angular with day compartment of the earth array. The by temperatures will be search accomplished pattern existing by touchdown. ing a search pattern for near required restricted terminator landings determining spacecraft roll attitude 185 from of the a most solar panel data roll and for night or near noon landings by the assumption probable attitude. After ing from solar lunar initial incidence libration twice positioning, angle must per and be earth repositioning the planar array of the to solar panel pointing intervals. is to follow errors the chang- correct resulting accomplished day the during at the at periodic lunar day Repositioning although prior to it tele- approximately may vision be desirable operation, anticipated, such ratio. as to position to obtain antenna video specific times, optimum signal-to-noise When two celestial the landing site is in known, spacecraft earth spacecraft coordinates. positions and star in attitude For spacecraft may day be determined the from from bodies will and known sun array landings, spacecraft solar frames ing, atures array the panel with provide planar and coordinates from survey case low of the positions mirror be be positions For of television a night landtemperthe planar their corresponding may may positions. because only the their survey and earth cameras position inoperable available ambient by if earth acquisition is successfully accomplished. Spacecraft Lunar Day Ope rational Capability The shown solar mode may lunar day operational The the capability nominal case of the solar the of the Surveyor output charge power of as A-ZIA configuration of in the time normal or is in Figure angle of be is 13-15. shown and to the for panel a function optimum regulator level which actually operation available by the represents spacecraft. of optimum panel by the maximum The amount at various generated to The dissipate degree to times is the power limited heat which capability by the thermally charge power the controlled regulator is utilized of the the compartment compartment. depends thermally charge in both energy by on the generated the available and is solar limited the heat mission sequence compartin A comand B. of operation ments partment In general, all capability by controlled regulator compartments is available to dissipate A and with desired the generated subsystems landing, within be a be the landing optimum located spacecraft day a lunar operations sufficient constraints near the solar to con- duct The case start is imposed day/night charge the compartments. in before which the single exception time would may not The terminator, the battery sufficient of the in available of may to fully the be lunar terms night. of watts capability heat that thermally dissipated controlled under compartments thermal tray shown of 186 I00 SOLAR I PANEL OUTPUT POWER _ 75 _ OCR IN NOiMAL MOOE (NOMINAL] 5o NOMINAL COMPARTMENT DISSIPATING CAPABILITY XIMUM 25 THERMAL TRAY THERMAL TEMPERATURE, +125°F COMPARTMENT_ 0 1.0(, d >u _o 0.75 I I \ _, _,_ J % '_ -_,CROMETEOR,TE // OETECTOR. SEISMOMETER, ALPHA SCATTERING OR NARROW BAND ENGINEERING DATA T ANSMISSION ' _/ /SURFACE z _O I,- I I _TELEVISION TEMPERATURE LOW LIMIT i , SAMPLER '7 _,_,_ SURVEY. FRAME _ _ J PER ./ I I I I j SUR_FACE SAMPLER LOW TEMPERATURE LIMIT 0.50 _. _ _ _. TEPPING _ OPERATION TELEVISION 3.6 sec ._" ._" 0 =E 2E 0.25 I LIMIT O 50 IOO TIME [ 90 I 60 ] 30 SOLAR FROM 150 DAY/NIGHT I 0 ANGLE, DEGREES 200 TERMINATOR, HOURS I 30 250 IE I i I I 350 I 90 300 I 60 _SPACECRAFT EXTERNAL THERMALLY SENSORS NOT CONTROLLED COMPARTMENT INCLUDED EXCEPT AS SPEClFED CAPABILITY'ON_; FIGURE 13-15. LUNAR DAY FOR EQUATORIAL OPERATIONAL LANDING CAPABILITY temperature under assumed ment the conditions compartment includes of +125 ° F standard and as such represents conditions. the maximum capability environmental as and well The environment on the and compart- the lunar by environment solar panel as the influence array radiator surface the planar positions temperatures. The (a) (b) (C) complement Survey Soil Alpha of scientific (2) surface instrument sampler instruments consists of the following: television mechanics scattering 187 (d) (e) The maximum by the heat Micrometeorite Seismometer operational steady-state dissipating allowable by to the detector capability cycling capability thermal the tray of which of the is the above permitted thermally instruments within controlled is 1Z5 ° maximum thermal F; is the shown constraints in terms of imposed the compartments. therefore, operation tray temperature maximum of compoof The maximum heat nents temperature as occurs well at dissipation internal compartments as a compartments 125 ° F. During the normal (a) (b) (c) (d) (e) the On mode Optimum Transmitter Transmitter Command Engineering required (f) (g) During Ig5 ° F mand thermal At Boost regulator on and auxiliary thermal period units tray of the on as required are cycle slightly the below comperiod of the instrument cycle the spacecraft is assumed in of operation charge on as follows: regulator in normal band or mode narrow band as required) {either wide connected receivers signal on to planar (Z) and array processor central signal processor on as Instrument the electronic compartment this period and rising. are temperatures instrument the During assumed the Off to be only receivers tray lunar operating less with than resulting decay in the temperatures noon, per to slightly I75 ° F. television in the mapping mode the operation typically of the results survey (3. 6 seconds mately Off or partment B. frame) and in thermal A and dissipations B, of approxiDuring in comthe 36 watts compartment A by Ii watts cooling in compartments period approximately and average no respectively. are dissipated 3 watts dissipations the command in order receivers to limit B the occur in compartment A is Therefore, and heat dissipation in compartment mapping mode to 6 watts limited in compartment cycle of about to 4 watts I0 percent the operation or 6 minutes of the per to a duty hour. 188 The operation of the micrometeorite detector, alpha scattering instrument, and seismometer is shown in figure 13-15. The above instruments may be operated either individually or simultaneously at essentially the same duty cycle. The principal operating mode of the surface sampler, the continuous stepping of one of the four drive axes, is shown in figure 13-15. The operation in the accelerometer mode although requiring ard is therefore not shown. The spacecraft capability wide-band telemetry is only of short duration shown in figure 13-15 is subject to a number of variables. The first of these is the operating mode of the optimum charge regulator. It was previously stated that the regulator was operated in the normal mode during the On period and turned off during the instrument Off period. A tradeoff may be made, however, in battery charging versus data transmission. If the charge regulator is turned off or operated in the bypass mode during transmission, the reduction in the heat generated in compartment A would, if compartment A were the limiting compartment, allow increased transmission time. If battery charging is important during the period when the indicated duty cycle is less than i00 percent, the battery may be charged during portions of the off cycle (thereby causing added thermal dissipation within the compartment) with a resulting decrease in the allowable transmission time. Other variables affecting the illustrated capability include optimum charge regulator variations due to the dispersions associated with the solar panel output power, variations in the dissipations by spacecraft electronics, the optimum charge regulator and the boost regulator due to variations in the battery terminal voltage, and variations in the actual compartment dissipating capability due to lunar environment and compartment thermal parameters. The above variables are potentially capable of significantly affecting the illustrated capability during the noon interval. Additional tion. than will until with vision At the thus the allowable provide maximum landing, may be capability maximum. a limited tray is available to optimize temperatures The transient compartment capability of IZ5 ° F engineering thermally During allow the the the lunar sequence of operatypical case will be due less capacity to its mass operation case, touchdown, compartment in the thermal for continuous spacecraft In the normal and temperature is reached. assessment restricted region a noon survey the postlanding completed the initial teleas operation, transient time. before operation indicated the in figure 13-15 is required. would for of restricted nonoperation which of equipment may be used accumulation of additional at some desired capability extended transmissions 189 A tradeoff the panel may above also be made heat could it may panel output in the sources utilization during in an increase to to the of the the planar array or the solar reduction heat panel. of Since the represent noon in interval, compartment planar lower its temperatures Although of the solar result be radiating the and dissi- capability. positioning yet pation retain undesirable alter sun the to array position, off-normal could provide temperature thermal a minimum if additional compartment capability desired. Spacecraft The expected During l0 of at ° F, Lunar transit battery lunar night Night energy state Operational deficit, of charge Capability nominally of 2800 1000 watt-hours A losses. In 6.8 B. than operation that the The order and and Table to watt-hours at B are 13-8 maintain 3.9 watts will a temperature controlled presents the of at will 2375 is of fully at a result of in an 70 ° F. and operation to lunar minimize night compartments heat losses. 50 ° F summary respectively, compartment the above in and an heat compartments heat must be of available If the before available the for temperatures, compartments average for during a load lunar the a nominal A of and less watts battery dissipated 50 ° F energy landing day/night the night The tures point, engineering is presented of may by discharge ampere a temperature the one-half to reduce remaining occurs night day such about watt-hours. charged will be battery terminator operations. heat be the dissipation provided operation data. in the figure survey may The is followed survival decay For to the 0 ° F, case energy be The nominal 3375 watt-hours energy required by of heaters the or, for the more maintenance efficiently system under of various of from to compartment an acquire operating or operational scientific temperastandor telecommunication night If the is by not taking of of limited allowable landing assessment of the it is of spacecraft capability maintenance required, advantage the battery lunar 13-16. television obtained conditions the night thermal temperaThe for maximum survival survi- communication spacecraft compartment above control heating val additional of at the the capability capacities. tures extended A to complete by the discharge slow should minimum a night decay be compartment to the battery desirable the interval temperatures. required temperature. to spacecraft touchdown allocate a time the of compartment small portion survival. of A the nearly available complete for the touchdown survival is assessment expected. 190 TABLE 13-8. AZI-A COMPARTMENT Model LUNAR NIGHT HEAT LOSS SUMMARY AZI-A A* Heat Loss Watts B** Heat Path Basic less compartment wiring harness Compartment at 50 ° F Compartment at 10°F Supports Thermal Mylar Thermal Wiring Basic Low inserts 3 coax cables low switches super tunnel harness bus conductance insulation 1.52 1.13 2.32 0.76 O. 75 0. 67 1.38 0 0.34 0.68 0.26 0 conductance Tear strip (34 payload strips) -,--,--,0.16 0 Scientific TV cameras 2 and 3 0.16 0 0 negligible 0.06 0.16 0.06 O. O9 0 Surface sampler Seismometer Alpha scattering Micrometeorite detector Total compartment on on design design low losses shown shown conductance on on drawing drawing wiring 0.16 6.8±0.5 3.9 revision revision E. E. ± 0.25 *Based **Based ***Assumes 261214 361240 harness. 191 5DO0 _t BATTERY DEPLETED, COMPARTMENT TEMPERATURE DECAYS TO OeF A POST LANDING ENERGY ALLOCATION OF 5ow-hr REQUIRED FOR ENGINEERING ASSESSMENT AND PLANAR ARRAY/SOL.AR 4000 "K-')(" 0 z i < 3375 ±i75 _'')('_ 3000 0.SAMP LOAO = 3373w-hr "_ , --'_'-I" ESTIMITED _"_'UULLY BATTERYLCHARGE DISPERSION, CHARGED BATTERY AT 50"F 4- 30" AND PANEL_ --POSITIONIN i _._ w z w 2373 ±seo 2000 .... r _ • I-_'_ E-N-E'I_G¥-'A"V'AILABLE _ AT TOUCHDOWN WITH BATTERY _TEMPERATURE REDUCED TO _ _ _ "_ I NOTV SURVIVAL_ I _ \ I000 TVSURV_VAL. _TA OPERATION SEISMOMETER 30% OPERATION 20.2 w REQUIRED 0 4OO ,00 TIME FROM f 30",. I I I l 200 _ _ _.'.-;._-X,;,_-_, .......... _ I _ _ I _-_" _ \ _ \ _. _ \ _. _ _. -_ _1 iO0 TERMINATOR HOURS 0 NIGHT/DAY A DAY/NIGHT T E R M I NATOR ' TERMI A OAY/NIGHT NATOR FIGURE 13-16. LUNAR NIGHT SURVIVAL CAPABILITY It of is the desirable wide-band after lunar to acquire transmission the earth with the high The gain survey low antenna television for the may assessment be inoperaof capability. because of tive the touchdown, night. however, the environmental temperatures Hypothetical A shown Sequence of Operation of operation touchdown and planar completed for the case of an equatorial the sun landing and the earth is hypothetical sequence The panel in figure by 13-17. the solar survival array evaluation are completed second and acquisition with the during first hour the heat steadyof the initial initial television in the thermally survey in the hour. the Although maximum capabilities dissipated state controlled compartments the exceeds thermal compartment dissipating in the nominal within capability, case are transient to permit temperature compartments 2 hours expected tray completion constraint of the of of operations the thermal IZ5 ° F. 192 STATION TRACKING TOUCHDOWN SUN/EARTH SURVIVAL ACQUISITION ASSESSMENT PLANAR ARRAY/SOLAR REPOSITIONING TELEVISION NARROW COLOR SURFACE ALPHA OPERATION ANGLE SURVEY SAMPLER SCATTERING PANEL MAPPING SURVEY OPERATION INSTRUMENT SEISMOMETER MICROMETEORITE ENGINEERING DATA DETECTOR TRANSMISSION -% SOLAR APPROXIMATE TIME OVER OPERATIONAL INDICATED DUTY CYCLE ASSUMING OR PERCENT NOMINAL ON SPACECRAFT ANGLE, DEGREES r--] INTERVAL COMPARTMENT NON-LIMITING CONTINUOUS TELEVISION CONTINUOUS ENGINEERING (_) SURFACE PICKING NOT THERMAL DISSIPATING BY EXTERNAL SENSORS INSTRUMENT INTERRUPTED ENGINEERING INTERROGATIONS, OPERATION 5 rain EACH DATA S CAPABILITY. ASSUMED OVER HALF INDICATED HOUR INTERVAL. TRANSMISSION rain EACH HALF WITH HOUR, MINIMUM FRAMES. SAMPLER OPERATION IN STEPPING ALTERNATED REQUIRING WIDE-BAND INDICATED DUTY CYCLE TELEVISION TELEMETRY INCLUDED FIGURE 13-17. HYPOTHETICAL EQUATORIAL LUNAR LANDING PHASE ASSUMED SEQUENCE-- Operations compartment during the remainder capability television exceeds of the lunar indicated camera day are shown 13-15. as constrained by the dissipating that the in figure operating Assuming thermal mally mapping may veys be capability, imposed established by the and per mapping mapping thermal by ther- its characteristics, controlled surveys conducted each the thermal during 1000 the near frames constraints noon each, tape. compartments of approximately by predetermined color interval, at 3.6 Two The and black seconds white frame, suroperacooldown command are complete television to allow with of three filters included. status tion is interrupted of the compartments. If sufficient micrometeorite to monitor the spacecraft telecommunication detector will be bandwidth operated is available the seismometer only for and continuously, interrupted 193 compartment thermal cooling as required and during the wide-band transmissions required by other scientific instruments. It is assumed that the sensors do not constrain operation during the noon interval. The operation of the soil mechanics surface sampler is conducted in two modes. Scraping, digging, and mapping of the lunar surface is conducted in a narrow-band telecommunications mode with the stepping alternated with television frames in the wide-band mode as required. The picking operation is conducted in the wide-band telecommunications mode with television viewing used for remote control. The 167° F maximum nonoperating temperature limit of the alpha scattering instrument sensor, together with its limited available view factor to space, could result under worst case conditions in potential permanent damage to the sensor if allowed to remain in the stowed position after a touchdown at lunar noon. Since the 3-hour standard sample count is conducted in the stowed position and is limited to a maximum interruption of 30 minutes the deployment of the instrument will preclude the acquisition of standard sample data. It is assumed that the above worst case situation must be alleviated by thermal design if additional thermal studies of the sensor head and its environment confirm the existence of an actual problem. Therefore this worst case condition is not considered in the illustrated typical sequence of operation. In order to conform to the instrument maximum interruption constraint, the alpha scattering experiment is not initiated until continuous spacecraft operation is permitted by the thermally controlled compartments. During the lunar day and night additional operations are required to support the requirements of the scientific payload. The assessment of touchdown survival will provide data necessary for the operational planning associated with the scientific payload. The positions of the sun, earth, and stars in spacecraft coordinates obtained during the initial acquisition period and television survey will provide data necessary to compute spacecraft attitude. Engineering interrogations are provided each half hour to monitor spacecraft status. Repositioning of the solar panel and planar array should be performed at intervals of about IZ hours, although if the rate of lunar libration is less than maximum, repositioning of the planar array may be conducted at less frequent intervals. The solar incidence angle on the solar panel is thereby maintained at less than 3.5 degrees and the planar array positioning error may be maintained at less than I degree. In an 194 optimum sequence the final positioning of the solar panel prior to the start of lunar night causes it to face in the direction of the norning sun, with a full battery charge achieved at the time of final positioning. 195 PRECEDING PAGE _'_ K,_';_-,,, NOT FILMED. ,.,. APPENDICES Appendix ration, A lists specifications and function that establish Surveyor namely, design Spacecraft, the basic requirements, ModelA-ZIA. bus and which the the configuThe scientific specifica- performance, into two are of the list is divided payload. tions are These major categories, divided further into the subsystems under listed. B lists characteristics under only, C gives and subsystems e_cept for data to which those and for Surveyor apply. in the Spacecraft, All items Model are A-21A. Appendix These tional are listed they for informa- reference Appendix that appear performance preceding sections. which exist the physical differences between the A-21 A-ZIA spacecraft. 197 pRECEDING PAGE BLAN_ NOT..,I_|I-I_.-_P' APPENDIX A. DOCUMENT AND SPECIFICATION LIST BASIC BUS: Structural and Vehicular Subsystem Item Document DS Number 230029 Document Spaceframe Configuration Name Design Vehicle DS 230003 Spaceframe Integrating and Unit Structure Gear Gear Requirements Shock Absorber 3 4 DS DS Z38900 Z38901 Landing Landing Column 5 DS 238904 Landing Blocks Gear Crushable Body DS GS Z36130 226100 Antenna/Solar Electromagnetic Specification, Spacecraft Equipment and Panel Positioner Interface Surveyor Associated CS Z39506 Spacecraft Grounding, Shielding Design Bonding, Parameters, and DS Z38704 Spacecraft Compartment Thermal A Thermal B Control, I0 DS Z38706 Spacecraft Compartment Control, 199 Engineering Instrumentation Subsystem Item ll Document CS CS Number 988653-2 988654-I0 239004 239004 Document Temperature Name Sensors 12 13 DS DS Accelerometers Engineering Sensors, Amplifier Measurement AccelerometerSystem Propulsion Subsystem 14 PS 238611 and Main Thiokol Rocket Retro Rocket Main Engine Retro- E155-62 Spec, Engine 15 DS PS 238666 238610 262526 and Surveyor System Safety Main and Vernier Propulsion 16 PS Arming Rocket Assembly, Engine Retro Actuator 17 DS 234675 Roll Electrical 18 239513 Power Subsystem Power by and Thermal Event Assembly Dissipation Functional Panel 19 DS PS 237601 237787 237790 237901 231631 231632 and Solar 20 21 22 23 PS PS DS DS Solar Battery Battery Boost Panel Solar Cell Module Charge Regulator Regulator 200 L. Telecommunications Subsystem Item 24 Document 239511 Number Spacecraft Document Command for Name Assignments Payload Z5 Z31681 Decibel Summary 26 DS 231706 Spacecraft Transmitters 27 28 DS DS Z31707 231718 Receiver Scientific Allocation and Margin Telecommunications Transponders Antennas Telecommunication and R-F Switching Decoding Decoder} Signal Signal Data Rate 29 DS 231641 Central Command Unit (Central 30 31 3Z 33 34 DS DS DS DS Z31711 Z31710 Z316!6 Z31613 Engineering Central Low Signal Spacecraft Control for Processor Processor Auxiliary Auxiliary Channel Payload Processing Data Z3951Z Scientific Flight Control Subsystem 35 36 37 38 DS DS DS DS PS 234600 234630 234622 234636 Z 34661 234621 234610 and Flight Control Sensor Group Inertial Reference Primary Sun Sensor Unit Inertia - Burnout Sensor Switch 39 40 PS DS Canopus Flight Sensor Control Electronics Unit 201 Flight Control Subsystem (Cont) Item 41 42 43 Document DS DS PS Number 234623 232601 232902 Secondary Altitude Radar Velocity Document Sun Marking Altimeter Sensor Name Sensor Radar and Doppler (RADVS) - Gas Tank 44 PS PS 234641 234640 231621 Attitude Gas Jet System Jet Attitude Controls Camera 45 DS Approach Television SCIENTIFIC PAYLOAD: 46 DS 231622 Survey Television Camera- Spacecraft Television 47 FR Z31611 Alpha Telecommunication Scattering Instrument Auxiliary 48 FR Z31612 Micrometeorite Instrument Ejecta Auxiliary Auxiliary Instrument Detector 49 5O FR FR 231715 231716 Sample Processor Soil Mechanics Auxiliary 51 52 FR FR 239319 239320 Alpha Scattering Experiment Ejecta Detection Micrometeorite Experiment 53 54 55 56 FR FR FR FR 239323 239334 239335 239389 Soil Mechanics Seismological Seismometer Soil Experiment Experiment Auxiliary Sampler Mechanics-Surface Auxiliary 2O2 Television Subsystem (Cont) Item 57 58 59 6O 61 Document FR Number 239390 Document Name Soil Mechanics-Surface Sampling Experiment Ejecta Detector IS 239302 IS 239303 IS 239330 IS 239381 Micrometeorite Alpha Single Scattering Axis Experiment Seismometer Sampler Soil Mechanics-Surface 203 _-7 pfKECEDING pAcE _LA'_"!" b_O'_£_L_ED. APPENDIX B. CHARACTERISTICS DATA System Item Number /1 Spacecraft Transit / Item Injected Time AV (Nominal) at 20 hours Weight 2221.27 Data /2 66 hr 30meters/sec 15 fps (vertical); 5 fps (lateral) Midcourse 114 Soft Landing Capability _6o tb paytoa20 HOURS ,_ / A-21 A-2IA A-21 AND A-21A _,,=, bJn =E=E I--LU 80 O. =E 0 L) TEMPERATURE TOLERANCES 60 TO BE DETERMINED t I AND SUN TRANSIT PHASE _I_LUNAR PHASE_ i ACQUISITION VERIFICATION AND ACQUISITION MIDCOURSE CORRECTION _ c w 120 rr b J03 8O Z z :::::::::::::::::::::::::::::::::::::::: ...... ::::::::::::::::::::::::::::::::::::::::::::: ,,,o_ 4O ..... 0 _:i:_:_:!:_:_iiiililililililiiiiiiii_:_:_:_:_:i:_:i _ 0 4 TIME 12 AFTER LAUNCH, HOURS 20 60 65 0 66 I rIME 2 AFTER 3 4 TOUCHDOWN, 5 HOURS FIGURE C-2. COMPARTMENTS TEMPERATURE PROFILE A AND B THERMAL DIFFERENCES TRAY 221 60 _ I 1 I COMPARTMENT COMPARTMENT A B LOAD OF 3w COMPARTMENT IN COMMAND ALL LOW A CONSTANT RECEIVERS COPPER WIRE HARNESS ON A-21 CONDUCTACE WIRING HARNESS ON A-21A LANDING SITE: LUNAR EQiATOR ¢n 40 l b. 0 /// I"125 II1 IZ rr L_ O. =E I-" _ _1 < ¢J W -r 20 Z U.I A-ZIA Ilg G. 0 0 ° I.Z / / 0 ,., ,s Q. ,s o 130 _ ' 135 -- -2O 0 SOLAR 30 iNCIDENCE ANGLE,'r/, 60 DEGREES 90 FIGURE C-3. COMPARTMENT DIFFERENCES, DISSIPATING LUNAR DAY CAPABILITY 222 60 \ 5O DOPPLER LIMJT / ELLIPSE CORRECTION 99% FOR DISPERSION NO MIDCOURSE I / / / I I ALTIMETER 40 LIMIT \ z 5O A-21A / I,- t t \ 99% FOR DISPERSION MAXIMUM ELLIPSE MIOCOURSE \ % J ,_ CORRECTION IN / I 2O A-21 ANO A-21A CINEAR DOPPLER / / / / IO COMMAND DESCENT TRAJECTORY o 2 VELOCITY, HUNDREDS OF FEET 6 PER SECOND io FIGURE C-4. VERNIER DESCENT PHASE DIFFERENCES 223

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