Key X-33 Events in 2000
Click on the date to go to a related news release and any associated photos.
Many thanks to Dill Hunley, Historian, NASA Dryden Research Center, for some
of the information found here.
Construction of the X-33 vehicle continues. Communications with one of the two
vehicle health monitoring computers has been established, and the Skunk Works is
resolving an anomaly in order to establish communications with the second vehicle
health monitoring computer. Meanwhile, Swiss Air has purchased the Boeing hangar
where the X-33 is being assembled, and will take ownership on June 1, 2000. The Skunk
Works lease agreement is effective through December 2000.
As part of the liquid hydrogen tank failure investigation, internal scaffolding
has been installed in the tank in order to allow nondestructive investigation of
the tank's interior. The failure investigation board currently hopes to issue a preliminary
report during the second week of February.
2000 January 7
Aerospace Daily reported today that the X-33 tank failure investigation
team probably would not release its findings until the middle of February. Meanwhile,
engineers at Lockheed Martin's Michoud facility (New Orleans) have started preliminary
design work on aluminum-lithium replacement tanks, which would be ready in about
a year and a half. However, the article pointed out, the metallic tanks would not
demonstrate one of the critical technologies for a commercial RLV, namely the composite
fuel tanks. Aerospace Daily also reported that the metallic tanks were just
one option under consideration, but did not disclose what those other options might
be. The tanks are also critical to the assembly of the X-33 vehicle, as the two liquid
hydrogen tanks support the vehicle's metallic thermal protection system panels over
a large part of its structure, so that vehicle assembly cannot be completed until
the tanks are fixed.
2000 January 7
According to Space.com today, Lockheed Martin agreed to invest an additional
$100 million into the X-33 project over the next two years to repair or replace the
failed fuel tank, provided that NASA does not terminate the program.
2000 January 9
A Skunk Works quality assurance team completed nondestructive investigation of
the interior of liquid hydrogen tank #2 in Huntsville, Alabama.
2000 January 10
Aerospace Daily reported today that tests on the X-33 failed liquid hydrogen
tank were continuing. Members of the failure team will begin cutting samples this
week from the tank in hopes of identifying why the tank failed. Samples of the tank
composite material will be examined under a microscope, and other analyses will be
conducted, as part of their work, including subjecting the same type of composite
material to temperature, pressure and other environmental factors similar to those
encountered during the November 1999 tank failure. The team's final report probably
won't come out until the middle of next month [though a briefing is scheduled for
February 7]. In the meantime, the Skunk Works is considering a switch to aluminum
liquid hydrogen tanks for the X-33, according to Aerospace Daily.
2000 January 14
Aerospace Daily reported today that Gary Payton, NASA deputy associate
administrator for space, after five years with the space agency, would be leaving
NASA in the spring for a position in the private sector.
2000 January 19
Starting today, a Red Team began review the combined X-33 and VentureStar RLV
program. Chairing the Red Team are Dr. William (Bill) Balhaus (Lockheed) and Dan
Dumbacher (NASA Marshall). The first session consisted of a technical overview, scheduled
to be completed on Friday, January 21, followed by a second set of sessions to run
February 1 - 4. The second sessions would allow Red Team members to focus on certain
areas in more depth as required to report out to the Lockheed Martin corporation
on the health of the program.
2000 January 20
During the past week, the Skunk Works reached a key milestone when communications
were established between the vehicle control computers, the vehicle health monitoring
computers, and the power distribution systems. Also, Oceaneering Thermal Systems
(OTS) continued to install tiles at a rapid pace. Complete installation includes
tile bonding, bond verification, and gap filler fabrication. The body flaps are at
70% tile bond complete, the right elevons tiles are 90% bonded, and the left elevons
are 75% bonded. Bond verification is also proceeding well. Gap fillers are being
fabricated in parallel with tile bonding. Currently all assemblies are working to
scheduled delivery of February and March for right and left, respectively.
Lockheed Martin Missiles and Space received official approval to begin design
and fabrication of the replacement hydrogen tanks with aluminum. Both Lockheed Martin
Missiles and Space and the Skunk Works are gearing up to execute the redesign. FAMSCO
is scheduled for the middle to latter part of February after some preliminary design.
Also, the Skunk Works anticipates an additional 10,000 to 13,000 man-hours of fabrication
effort to replace thermal protection system substructure elements because of differing
coefficients of thermal expansion between the composite and aluminum tanks.
2000 January 21
NASA's Stennis Space Center today at 11:09 p.m. EST completed a 60-second test
of the Rocketdyne X-33 linear aerospike engine. The test demonstrated the vectored
thrust capability of the engine for the first time. This vectoring capability (analogous
to the gimbaling of a bell rocket engine) will help to steer the vehicle during ascent.
The test also compared different hydrogen and oxygen mixture ratios (5.5, 5.3 and
4.7) at different thrust levels (60%, 80%, and 100% power). The test lasted three
times longer than previous hot firings. During the test, technicians also varied
the thrust across the actively cooled aerospike "ramp" by 5%.
The X-33 aerospike engine completed a successful 125-second test this evening.
The test included throttling and calibration at various power levels to update the
engine performance model. The X-33 vehicle will use thrust vector control to steer
itself in flight. Thrust vector control allows vehicle designers to avoid the weight
and complexity of engine gimbaling mechanisms, and in turn this capability supports
the effort to institute aircraft-like operations. Today's test was the longest test
run to date at 100 percent power, exceeding the previous test by 30 seconds. The
successful test also marked the first demonstration of plus or minus 15 percent thrust
2000 February 9
The Red Team chaired by Dr. William (Bill) Balhaus (Lockheed) and Dan Dumbacher
(NASA Marshall) completed its review and provided a preliminary briefing. The team
was impressed with the progress made on the X-33 and RLV Programs. They indicated
that the basic X-33 approach was sound and that there were no obvious showstoppers.
They also recommended steps be taken to ensure the success of the mission in light
of recent launch vehicle failures.
2000 February 16
The latest and ninth test of Rocketdyne's X-33 linear aerospike rocket engine
took pace today at NASA's Stennis Space Center. During the 175-second-long test,
varying mix ratios and power levels tested and confirmed again the engine's thrust
The tenth test of the X-33 linear aerospike engine took place this day at Stennis
Space Center, Mississippi. It ran only 75.44 of a planned 220 seconds. Technicians
attributed the early shutdown to a change in the engine's new mixture ratio controlling
software. Initial inspections revealed no significant damage to the engine or supporting
equipment. The next test is slated in about a week. More details in the Press
2000 March 22
Today, a complete and successful 220-second test of the X-33 aerospike engine
took place at NASA's Stennis Space Center. The test validated a new mixture ratio
control algorithm and incorporated several reactive control logic updates. The next
engine test is scheduled for April 3, 2000, and will last a full 250 seconds, longer
than the engine is expected to burn on any given flight of the experimental vehicle.
For the actual flight from Edwards AFB to Michael Army Airfield, engine runs from
230 to 240 seconds will be required.
2000 March 28-29
The liquid hydrogen metallic tank Preliminary Design Review (PDR) took place
at Lockheed Martin Space's Michoud plant near New Orleans.
2000 April 6
The twelfth test in a series of fourteen tests of the XRS-2200 Linear Aerospike
engine took place today at 10:26 p.m. The planned duration of the test was 250 seconds.
Actual duration was 250.02 seconds. There were eight primary objectives. Initial
results indicated that all objectives were met. There were no anomalies and no engine
problems. The next test will take place during the week of April 17.
2000 April 11
During a hearing this day of the Subcommittee on Space and Aeronautics, Committee
on Science, U.S. House of Representatives, Sam Venneri, NASA Associate Administrator
for the Aero-Space Technology Enterprise, stated that the X-33 would have metallic
tanks. He also reported that the X-33 failure report, as well as the results of negotiations
with Lockheed Martin, would be released in about 30 days. The report has been completed
in preliminary form, he said, but NASA was currently is studying it before release
to the public.
2000 April 14
The NASA fact-finding team for the Cost Recovery Proposal reviewed all elements
of the proposal, and during meetings this week at Lockheed, the firm answered the
remaining questions from the review. Meanwhile, progress on the X-33 vehicle continued.
The latest versions of the avionics and simulation software became available for
testing this week and was utilized to test the electrical power control distribution
system integration testing procedures, and dry runs of the vehicle health management
system integration testing procedures were completed. Also, the Data Interface Units
hardware arrived from Honeywell and was installed in the ITF.
NASA today announced that Jeff Bland, an engineer and 17-year veteran of NASA's
Space Shuttle program, had joined the NASA X-33 Program Office in Palmdale, Calif.,
as deputy manager. Previously, Bland managed the NASA resident office at Pratt &
Whitney in West Palm Beach, Florida, where he led a NASA team working with Pratt
& Whitney to deliver high-pressure turbopumps for the Space Shuttle Main Engines.
He was assigned to the NASA Resident Office at Pratt & Whitney in 1988, after
serving in 1987 on the NASA team established at Thiokol, Inc., in Brigham City, Utah,
to help redesign the Space Shuttle Solid Rocket Motor following the Challenger accident.
2000 May 12
The fourteenth planned hot-fire test of the X-33's XRS-2200 linear aerospike
engine took place today. The engine ran for a record 290 seconds before NASA Stennis
Space Center engineers shut it down, when a critical flexible seal began to erode.
The seal was designed to prevent hot exhaust gas from circulating into the engine
cavity. Inspections after the test revealed no other damage to the engine or related
hardware. Previously, the seal had been hot-fired and exposed to engine exhaust for
775 seconds, the equivalent of more than three flights. The conditions under which
the seal eroded (low power operation at sea level) would not be present during flight,
so the incident was not considered a serious anomaly.
2000 June 2
The Skunk Works started fabrication of the first pieces of the new aluminum lithium
liquid hydrogen tanks.
2000 June 28
The X-33 Quarterly Program Review took place over three days at Boeing's Canoga
Park, California, facility. The review covered all elements of the program and included
reports from the NASA Program Manager and the individual NASA Centers. The NASA team
wanted an in-depth understanding of all program activities to date. Approximately
60 NASA engineers participated in the review.
2000 July 19
Work presently focuses on the righthand body flap cove area. In three weeks,
test fitting of the righthand body flap will take place in order to trouble shoot
the complex seal system in this area. Work is continuing on the lefthand pod area
and umbilical door surround structure. Wire harnesses for the vertical stabilizer
actuators has been completed. The four righthand reaction control systems thrusters
have been installed and plumbing for this system has started.
The X-33 liquid hydrogen tank failure report was released today. According to
the failure report, the cause of the debonding was microcracks in the composite inner
and outer skins. The cracks allowed pressurized hydrogen to seep into the core from
inside the tank and caused the nitrogen gas maintained outside the tank as a safety
measure to be "cryopumped" in through the outer skin as the liquid hydrogen
chilled it. That produced pressure that was higher than expected in the composite
core, which in turn caused the separation. Aiding the separation was a piece of scrap
polytetrafluoroethylene tape in the composite structure and a known weakness in the
strength of the adhesive used in laying up the structure caused by the amount of
time it took to apply the adhesive to the large tank pieces. However, the manufacturing
flaws in the tank were secondary to the flawed design itself in causing the failure.
A copy of the report is available in "pdf" (Adobe Acrobat) format at the
Marshall Space Flight Center's X-33 Website.
2000 August 11
Additional progress has been made on the X-33 vehicle. The reaction control system
(RCS) thruster mounts on the vehicle's left side have been completed, and the interface
points for the MLG support structure have been changed to enable an increased landing
weight for the vehicle. Also, development of the draft version of the Simulation
S/W Requirements Specification has been finished.
2000 August 15
Test stand activities for the aerospike dual engine firings currently scheduled
for December 2000 are proceeding as planned. A CDR is scheduled for September 13-14,
2000, and a Test Planning review scheduled for September 14-15, 2000.
A NASA Marshall press release announced today that preparations
were under way at NASA’s John C. Stennis Space Center near Bay St. Louis, Miss.,
for the final phase of testing to qualify the X-33 linear aerospike engine. The test
stand is undergoing modifications to accommodate two engines for simultaneous firings
in their flight configuration. The engine tests are scheduled to begin late this
year. Following successful completion of this series of engine tests, the engines
will be shipped to Palmdale, Calif., where they will be installed on the X-33 vehicle.
Approximately nine engine tests are planned. These tests will verify the seal between
the two engines; dual-engine start, stop, and operational parameters; and the ability
of the engines to control the X-33’s direction of flight by varying the thrust from
side to side and engine to engine. The tests also will verify the ability of one
engine’s turbo-machinery to power both engines should a set of turbo-machinery fail
A NASA press release announced today that the space agency
and Lockheed Martin had agreed on a plan to go forward with the X-33 program. The
plan included aluminum fuel tanks for the vehicle's hydrogen fuel, a revised payment
schedule, and a target launch date in 2003 on the firm's ability to win additional
funding under NASA's Space Launch Initiative.
The program restructuring provides milestone payments to Lockheed Martin's industry
team to complete testing and delivery of the hardware and software systems this year.
The plan places greater emphasis on mission safety and more ground demonstration
of critical technology prior to actual flight. The program requires no additional
funding from NASA through March 2001, but will need additional funding for completion.
Work on the X-33 vehicle has continued at the Palmdale, CA, assembly facility
during the tank investigation and subsequent negotiations between NASA and Lockheed
Martin. According to the press release, vehicle assembly
is currently 75 percent complete, and more than 95 percent of the vehicle's components
have been fabricated, tested, and delivered to Palmdale. All of the X-33's hardware
except the new hydrogen tanks is expected to be completed by the end of 2000. NASA
and Lockheed Martin are proceeding with design of aluminum liquid-hydrogen tanks
for the X-33, replacing the experimental composite tanks originally planned.
NASA announced today in a press release that two aerospike
engines designed to propel the X-33 sometime in 2003 had been mounted side by side
in a test stand at NASA's Stennis Space Center, Mississippi, for a series of at least
nine qualification firings scheduled for sometime later this year. The testing will
begin with short bursts and eventually will lead to full firings for durations needed
to send power the X-33 to landings in either Utah or Montana. The previous fourteen
engine test firings were on a single aerospike engine. The actual X-33 vehicle will
use two aerospike engines. One of the goals of the next series of tests is to determine
how the two engines will interact.
NASA today announced that X-33 program managers will meet with reporters on December
13th to discuss tandem test-firings of the linear aerospike engine. Participants
in the one-hour news conference are expected to include: Gene Austin, NASA X-33 Program
Manager; Cleon Lacefield, Lockheed Martin Vice President for X-33; Don Chenevert,
NASA X-33 Program Manager, Aerospike Engine Testing, Stennis Space Center; Mike McKeon,
X-33 Aerospike Engine Program Manager, Rocketdyne Propulsion and Power, The Boeing
Company, Canoga Park, CA. Instead of the nine tests beginning in December 2000 (see
October 24 above), they will start early in 2001.
2000 December 13
NASA and its business partners presented a positive and optimistic report on
the X-33 at a press conference broadcast over NASA TV. Cleon Lacefield, Lockheed
Martin Vice President for X-33, emphasized the importance of the aerospike tests
that began earlier this month and pointed out the program's major achievements to
date, namely, successful testing of how the lifting body will react with the aerospike
engine, successful testing of the liquid oxygen fuel tanks and the thermal protection
system, and successful testing of the avionics and vehicle software. Gene Austin,
NASA X-33 Program Manager, added that certification of the vehicle's lifting body
design through the entire flight regime in wind tunnels was another key program achievement.
Don Chenevert, NASA X-33 Program Manager for Aerospike Engine Testing, Stennis
Space Center, reviewed the successes of aerospike engine testing to date, then explained
briefly the kinds of tests that already began earlier this month. The main test
objective now is to evaluate how the dual engines operate. Mike McKeon, X-33 Aerospike
Engine Program Manager for Boeing's Rocketdyne Propulsion and Power division, Canoga
Park, CA, outlined the planned program of 11 tests and explained how the firing of
the two engines will be used to assist the X-33 in various flight modes, including
banking. The longest planned test will last 212 seconds. Toward the end of 2001,
the engines would be shipped to Palmdale, CA, for fitting into the X-33 vehicle.
In response to reporters' questions, Gene Austin explained that the 90-day extension
to the original cooperative agreement will expire on March 31. Lockheed, however,
has submitted a proposal to continue the program starting April 1, 2001, and the
firm, according to Austin, has a "good chance of success in extending the program."
He also announced that the aluminum liquid hydrogen tanks had completed their Critical
Design Review (CDR) and that their construction has begun, with some of the tank
panels already completed.
When asked about the status of the VentureStar full-scale operational vehicle,
Cleon Lacefield replied that it remained a "top effort" and that the firm's
Space Launch Initiative proposal has the VentureStar architecture. However, he added,
the VentureStar was not the only architecture proposed by Lockheed for the Space
Launch Initiative. Lacefield further explained that the aluminum tanks were "exactly
what we want for VentureStar." They would give the vehicle the same weight
per cubic-foot of volume as the composite tanks, because the liquid oxygen tanks
are "really state of the art." Moreover, the aluminum tanks would give
the VentureStar architecture an acceptable design margin to build the vehicle. Lacefield
stated that VentureStar risk reduction efforts would take place during the period
prior to 2005, and that the first VentureStar flight would take place sometime in
2010 to 2012.
Toward the end of the press conference, Gene Austin characterized the X-33 project
as the "most significant program in a long time" and the "best assignment
of my career." He then announced his retirement from the program and from NASA
effective January 3, 2001, and his return to Alabama during the summer of 2001.