A duplicate of a major component of the experimental X-33 technology demonstrator -- its liquid oxygen tank -- soon will undergo a series of stress tests at NASA's Marshall Space Flight Center in Huntsville, Ala.
Tests will begin this month on the approximately 6,000-pound, dual-lobe aluminum tank designed to carry 181,000 pounds of liquid oxygen. It is a structural test article and back-up flight tank and is identical to the flight tank. The oxygen tank is part of the X-33 fuselage structure, forming the forward third of the technology demonstrator. Twin hydrogen tanks form the flanks of the triangular-shaped vehicle.
The X-33 and future reusable launch vehicles must use tanks that not only hold propellant, but also conform to the vehicle shape and support fuselage loads from landing gear, control surfaces and thermal protection systems.
During testing of the tank, Marshall engineers will apply internal pressure and external loads to the tank. Conditions will simulate pre-takeoff, takeoff, ascent, return and landing.
The Marshall team will use water instead of super-cold liquid oxygen to simulate internal pressure loads. Engineers already have a good understanding of the effects of extremely cold temperatures on aluminum. Hydraulic struts attached to the tank's exterior will simulate external forces experienced by the tank during a mission.
Once the Marshall testing is complete, the tank will be cleaned, X-rayed, insulated and shipped to NASA's John Glenn Research Center in Cleveland, Ohio. The tests there will be used to evaluate operations with colder-than-normal liquid oxygen and liquid hydrogen, with a flight weight tank.
Lockheed Martin Michoud Space Systems in New Orleans, La., designed and built the tank. It arrived at the Marshall Center in February.
The 26-foot-long flight aluminum liquid oxygen tank was placed in the X-33 assembly structure early last year.
The X-33 is a half-scale, sub-orbital technology demonstrator of a future reusable launch vehicle. It is being developed under a cooperative agreement between NASA and the Lockheed Martin Skunk Works in Palmdale, Calif. Managed for NASA by the Marshall Center, the program is to demonstrate advanced technologies that will dramatically increase reliability and lower the cost of putting a pound of payload into space from $10,000 to $1,000.
The X-33 is scheduled to conduct flight tests beginning in mid-2000. It eventually will fly faster than 13 times the speed of sound and at an altitude of 60 miles to prove its technologies and systems.
Note to Editors / News Directors: Interviews and a photo supporting this release are available to media representatives by contacting (Dom Amatore name) of the Marshall Media Relations Office at 256-544-0034. For an electronic version of this release, digital images or more information, visit Marshall's News Center on the Web at: http://www.msfc.nasa.gov/news