ASCI Space Applications Policy by liaoqinmei


									          The X-33
Presented by Walter Goedecke
       April 24, 2007   1
   Background
   X-33 Specifications
   Project Complications
   Reason for Project Demise

   The X-33 project was part of the NASA
    Reusable Launch Vehicle (RLV) program
    initiated after the 1986 Challenger
   In January 1993, NASA, under
    Administrator Dan Goldin, ordered a
    series of internal studies, including the
    Space Transport System
   The second generation RLV was to
    replace the space shuttle.
   A projected order of magnitude operational
    cost reduction compared to the current space
    shuttle operations was foreseen.
    – This was to lower the $10k/lb payload launch cost.
   Some NASA projects to advance the single-
    stage-to-orbit (SSTO) program were:
    – DCX – a SSTO initiated by McDonnell Douglas
    – X-34 – the parent project of the X-33

   Unlike NASA, the Dept. of Defense took the
    path of developing a line of “evolved
    expendable launch vehicles” (EELV).      4
   This dual use RLV was to satisfy both
    the commercial launch market and
    government needs.
   RLV development, however, also
    required industry funding, since NASA
    couldn’t fund this by itself.

   The X-34 project was co-managed by Orbital
    Sciences and Rockwell International.
   The prototype of the X-34 was the one half
    scale sized X-33, a sub-orbital pilotless
    spacecraft to demonstrate proof of concept of
    a totally reusable single stage vehicle
   This vehicle was projected to cost $7 billion,
    using both public (NASA) and private
    (industry) funding.

   Phase I, the design phase, was
    awarded in Spring of 1995 to three
    industry groups to design the vehicle
   The groups and designs were:
    – Lockheed Martin – a wingless delta shaped
    – McDonnell Douglas & Boeing – a version of
      the DC-X
    – Rockwell – a space shuttle derived design

Comparison of the Lockheed Martin, McDonnell
 Douglas & Boeing, and the Rockwell Designs

                   Wikipedia            8
   NASA choosing among industry designs
    rather than designing in-house is a new
   The award went to Lockheed Martin,
    proposing their VentureStar vehicle, on July
    2, 1996.
   Phase II of the X-33 project commenced -
    NASA contributed $900 M and LM $200 M.
   Later, under Phase III, LM would build the
    VentureStar, using knowledge gained from
    the X-33 prototype.

Comparison of the X-33, the VentureStar,
        and the Space Shuttle

                  X-33 Specifications
   67 ft in length and 77 ft wide
   Only an internal fuel tank constructed of honeycomb composite
    walls and internal structures.
    – Light enough in order for the craft to demonstrate necessary technologies for
      single-stage-to-orbit (LEO) operations.
    – Therefore more reliable and safer space launch vehicle.
   Metallic thermal protection systems
   Composite cryogenic fuel tanks for liquid hydrogen and ligquid
   An aerospike engine
   Autonomous flight control
    – This was to be an unmanned proto-spacecraft
   Lifting body aerodynamics.
   The gross lift-off weight is 273,000 lbs
    – The gross lift-off weight of the shuttle is 4,500,00 lbs
The Lockheed Martin X-33

         Wikipedia         12
           Additional X-33 Pluses
   The unmanned craft would have been launched
    vertically, from a specially designed facility, and
    have landed horizontally on a runway at the end
    of its mission.
   Rapid flight turn-around times through
    streamlined operations
    – Unlike the Space Shuttle’s $500 M cost and lengthy
      turn-around time for each flight.

VentureStar on the Launchpad
       (Artists Conception)

             Wikipedia         14
VentureStar in Orbit
   (Artists Conception)

         Wikipedia        15
           Project Complications
   The parent X-34 program, however faltered,
    as joint government and industry co-
    management and co-funding was
   The X-33 program continued, with industry
    eager to initiate Phase II.
   Phase III, however, scared off private
    industry, since this required 100% industry
    funding and operation for a full-scale vehicle.
    – LM could not finish the project with their own
      financial resources.
    – LM said in 1999 that the project would not attract
      investors, and additional government backing was
      needed.                                        16
           Technical Problems
   Although 40% of the X-33 had been completed
    and the launch facility at Edwards Air force
    Base was 100% completed, problems occurred.
   Rocketdyne decided to use a heavy copper alloy
    (Narloy-Z) on the Linear Aerospike engines
    were on target, causing center of gravity to
    move aft wards.
    – This caused consequent redesigns, such as the take-
      off ramps

             Technical Problems
   Engineers and designers thought that the pressurized
    composite liquid hydrogen (LH2) tanks with hollow
    honeycomb walls would not work
   Alliant Techsystems built the LH2 tank,but lacked
    experience with composite tanks
   The first tank had de-bonded and was sent back
   Air would enter the honeycomb of the second tank
    and liquefy, and thus failed
   Although engineers thought that filling the
    honeycomb structure with closed-cell foam would
    solve this, the idea was rejected due to the additional
    mass of 500 kg
           Technical Problems
   Because of engineer’s protests of the LH2 tank
    problems, the LOX tank was made out of an
    aluminum-lithium alloy
   Eventually, engineers started designing a Al-LI
    LH2 tank, with mounting evidence of failure
    – Even though the composite tank should be lighter
      than a conventional skinned tank, the extra struts
      needed to hold the honeycombed tank made the
      system heavier

                Other Problems
   With redirection of the fuel tank design, another
    problem developed.
   Ivan Bekey, a former NASA director, addressed
    the Subcommittee on Space and Aeronautics on
    April 11, 2001, stating that the X-33 had to
    continue with composite tanks, because:
    – “The principal purpose of the X-33 program is to fly
      all the new technologies that interact with each other
      together on one vehicle, so that they can be fully
      tested in an interactive flight environment. If that is
      not done, the principal reason for the flight program
   This stunning testimony helped cancel the
    project                                              20
           Project Complications
   Since this project had numerous setbacks,
    and the X-33 was years behind schedule, and
    grossly over budgeted, NASA terminated the
    project in March 2001.
    – The X-33 project was ended before ever being
      flown, even though by 2001 there should have
      been 15 test flights.
    – Although the project was to be 3 years duration
      and costing under $ 1 billion, it was 5 years with
      $1.5 billion spent
    – $1.3 billion spent on the project was public
          Project Complications
   Although the RLV program attempted to
    foster industry competition for an efficient
    means to orbit, it ended up as another costly
    venture that mirrored the days of continued
    pouring of money in a project until

          Project Complications
   Another difficulty was the required dual
    vehicle use for both NASA and industry
    launch capabilities.
   Also, NASA wants a vehicle to also
    service the space station, therefore it
    must transport humans
    – Space vehicles to launch satellites do not
      require the overhead for human flight,
      therefore this spacecraft will be cost
      prohibitive for industry
                    Side Note
         Human Transportation
 Rather than create an all inclusive RLV that will
  both launch satellites and transport persons to the
  space station, a dedicated crew transfer vehicle
  (CTV) could be built.
 This CTV would be less expensive than
  incorporating manned requirements into a second-
  generation RLV.
 A CTV could be launched by an EELV.

 Vehicle reliability is greater if cargo
  requirements are not too
  diversified.                                    24
X-33 at the Space Station

           Allstar          25
             Additional Concerns
   The Phase III concept of total privatization was
    – If industry backs out, will taxpayers have to foot
      the bill!
   Since this privatized vehicle was to also launch
    NASA and DoD satellites, the government may
    have wanted a second non-privatized means to
    launch payloads for national security.
    – This extra competition would also scare industry
      backers off.

X-33 Launching a Satellite)

            Allstar           27
              Design Problems
   A SSTO craft must reach what is called
    a "mass fraction" where the unfueled
    vehicle weight is 10% of the weight of
    the fully fueled craft.
    – This is difficult to achieve without staging.
   NASA came to the conclusion that the
    current materials and technology was
    simply not advanced enough for such a

             X-33 Afterthoughts
   The specific architecture of the X-33 limited
    timely completion and cost-effective
   LM’s admission of flaws to congress about
    this project did not help the entire RLV effort.
    – Contraversies abound: was this their way out
      of the deal?! (C.F.,
   NASA’s one-best-way model is inferior to
    multi-industry competition and trial and
    – Consider the X-Prize competition.

         Additional Afterthoughts
   Unexpected low demand for LEO and MEO
    mobile communication satellites.
   GEO satellites lasting longer.
   NASA and DoD still deploys the majority of
    – Result is launch service prices are not competitive.
   The Air Force’s Evolved Expendable Launch
    Vehicle (EELV) will subsidize technology
    development, and this may drive some
    launch costs down.

   Allstar Network, X-33 Shuttle Replacement;
   Berinstein, Paula, Making Space Happen.
   Bromberg, Lisa, NASA and the Space Industry
   Federation of American Scientists, Space Policy
    Project, X-33 VentureStar , lifted May 3, 2006,
   Space: The Free-Market Frontier, edited by
    Edward L. Hudgins.

          References – Cont.
, X-33: How the Central
    Planners at NASA Wasted Another Billion Tax
    Dollars, lifted May 3, 2006, from:
   Wikipedia, lifted May 3, 2006, from:
   X-33 VentureStar;
   X-33/VentureStar - What really happened;

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