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starship-design: FW: SSRT: X-33 Program in the Midst of Final Testing [...] (fwd)
From: firstname.lastname@example.org [mailto:email@example.com]On
Behalf Of Chris W. Johnson
Sent: Wednesday, September 29, 1999 8:41 PM
To: Single Stage Rocket Technology News
Subject: SSRT: X-33 Program in the Midst of Final Testing [...] (fwd)
Media Relations Department Sept. 28, 1999
Marshall Space Flight Center
Lockheed Martin Skunk Works
X-33 Program in the Midst of Final Testing and Validation of Key Components
The X-33 program is in the midst of final testing and validation of key
components as it aims for vehicle rollout in the first quarter of 2000.
Currently, the first of two composite liquid hydrogen tanks and the first
of four aerospike engines have entered validation testing. Once testing is
complete, these components will be shipped to the Lockheed Martin Skunk
Works, Palmdale, Calif., for installation on the X-33.
The X-33 is scheduled to begin flight tests in the summer of 2000.
X-33 Linear Aerospike Engine Scheduled to Be Fired this Week at Stennis
The engine test team is scheduled to test fire the first of four linear
aerospike engines being built for the X-33 at NASA's Stennis Space Center,
Miss., this week.
The first engine firing, which will last less than five seconds, is part of
a series of 41 test firings on four engines. Two of the engines have been
designated as test engines, while two will be used as flight engines on
the X-33. The engine undergoing tests is the first test engine.
The first six tests on engine No. 1 address engine ignition and start
sequence development. Each test is planned to last five seconds or
less. Once these tests are complete, Stennis crews will conduct eight
additional tests, each running no more than 250 seconds. These longer
tests will be used to verify engine performance at various mixture
ratios and power levels, as well as demonstrate thrust vector control
or steering. Planned total test duration on the first test engine is
Once the first engine has been successfully tested, two flight engines
will be tested in 11 runs for a total of 1,042 seconds. After successfully
completing the single-engine tests on the two flight engines in late
1999, the engines will be shipped to the Skunk Works to be mounted on
Beginning in January 2000, the two test engines will be placed on the
test stand together in a dual-engine arrangement to mimic the flight
configuration, and the two will undergo 16 test firings for a total of
The linear aerospike engines are being built by X-33 industry partner
Boeing Rocketdyne, Canoga Park, Calif.
Liquid Hydrogen Fuel Tank Enters Testing at NASA's Marshall Space
A series of pressure and stress tests has begun on X-33's right-hand
composite liquid hydrogen fuel tank at NASA's Marshall Space Flight
Center in Huntsville, Ala.
The 29-foot, 4,600-pound graphite epoxy tank is designed to carry
approximately 29,000 gallons of liquid hydrogen rocket fuel. The
right-hand hydrogen tank, along with its twin left-hand tank, form
the flanks of the X-33 and comprise roughly half its airframe.
Engineers at NASA Marshall conducted the second pressure test on
the composite tank by filling it completely with liquid hydrogen at
-423 degrees Fahrenheit Sept. 21. One of the objectives of the test
was to pinpoint seepage areas on the composite tank. When the tank
was pressurized to 20 psi, as expected, some hydrogen seepage was
noted. Technicians are applying sealant or patchwork to affected
areas before resuming pressure tests. The tank passed an earlier
pressure test with liquid nitrogen and a 5 psi helium leak test after
it was shipped to Marshall.
Similar patchwork was completed on the X-33's earlier 5-foot
composite test tank or the "Double D" tank. The 5-foot tank has since
successfully completed approximately 30 cryogenic cycles involving
the filling, draining and filling again of liquid hydrogen at pressure.
To fully validate the flight tank, six pressure and combined pressure
and structural loads tests will be conducted over the next few weeks.
Once validated, the tank will be shipped to the Skunk Works for
installation into the X-33.
The left-hand liquid hydrogen tank has completed assembly at Lockheed
Martin Missiles and Space, Sunnyvale, Calif., and awaits transfer to
Marshall in early October for its test series.
Alliant Techsystems, Clearfield, Utah, fabricated components for the
tanks, while a joint Lockheed Martin-Alliant team working in Sunnyvale
completed the assembly.
Umbilicals Tested, Installed on X-33 and Flight Operations Center
The launch umbilicals -- which will connect the X-33 to the cryogenic
gas, power and computer lines while the vehicle sits on its launch
mount -- have completed testing at NASA Kennedy Space Center, Fla.,
and have been installed on the vehicle assembly.
The vehicle's two 3-foot by 4-foot aluminum interface panels were
installed on the aft section of the vehicle assembly in August, while
two 15-foot-tall carbon steel tunnels that will house the launch
mount's version of the interface panels were installed shortly
Just like a car needs a pump, hose and nozzle to fill its gas tank, the
X-33 requires a complex system of panels, valves and hoses -- known
as umbilicals -- to transfer its super-cold propellants from on-site
tank farms, through the launch mount, and into the vehicle's internal
tanks. Carefully positioned latches and actuators are used to ensure
all connections are properly aligned and sealed during vehicle fueling,
and then quickly retracted and covered as the vehicle lifts off.
Software Build Nears Completion
About 90 percent of the software that will autonomously control the
X-33 from take-off to landing has begun integration, while months
of testing and independent verification remains. The software will
eventually be loaded on the X-33's three redundant mission computers,
allowing the vehicle to fly itself from takeoff at Edwards Air Force
Base, Calif., to landing at Dugway Proving Ground, Utah, and later
Malmstrom Air Force Base, Mont. The software also will give the
Lockheed Martin-led operations team the ability to monitor the
vehicle's flight from the program's eight-person control room at
the Flight Operations Center at Edwards.
Delivery is complete on five of the six segments of flight software.
The final software segment -- which adds vehicle approach and landing
to the current software -- is undergoing testing before delivery. Testing
of this segment -- referred to as "Build No. 6" -- will be complete later
this year. The entire software package will be put through its paces
constantly until the start of flight testing to monitor accuracy and
Industry partner AlliedSignal, Teterboro, N.J., created the software and
is working with Lockheed Martin and NASA to test and integrate the
software for the X-33.
Avionics Bay In Place
Installation of the X-33's avionics bay was completed Sept. 2 at the
Skunk Works. The titanium avionics bay is 6 feet by 11 feet with an
empty weight of approximately 300 pounds. The bay houses vehicle
control systems such as the three redundant mission computers,
communications gear, navigation equipment, and 28-volt and 270-volt
The bay sits in the center of the X-33 between the forward liquid
oxygen tank and the vehicle's two liquid hydrogen tanks. It is
positioned near the upper surface of the vehicle, directly below
one of the vehicle's upper thermal blankets, to allow for easy
access. This positioning allows for quick replacement of components,
supporting one of the X-33 program's overall goals of demonstrating
aircraft-like operations in a launch vehicle.
Duplicate Liquid Oxygen Tank Testing at Glenn Research Center
Testing will begin in November at Glenn Research Center, Cleveland,
on a 6,000-pound aluminum liquid oxygen tank that is a duplicate of
the tank previously installed in the X-33's assembly structure. The
testing is designed to obtain data on a system designed to densify --
or further cool to make more dense -- cryogenic rocket fuels.
The duplicate tank was built by Lockheed Martin Michoud Space Systems,
New Orleans, and shipped to Glenn Research Center for loading into
a test stand. Testing of the liquid oxygen tank is scheduled to be
complete in December.
By densifying cryogenic propellants, engineers hope to show that by
further cooling the liquids, tanks will be able to hold a greater volume
of cryogenic liquids, within the range of an additional 5 to 10 percent
of volume. This process could greatly aid the design and eventual
operations of a single-stage-to-orbit Reusable Launch Vehicle where
weight and fuel carrying capacity is crucial.
X-33 Flight Operations Center On Schedule to Support Vehicle Rollout
The X-33 Flight Operations Center at Edwards is online and on schedule
to support the X-33 vehicle arrival and flight test series, both scheduled
to occur in 2000.
Currently, all major ground system equipment has been installed at the
launch pad area, and checkouts are being performed as software arrives.