For release: Oct. 2, 1996
Ann C. Gaudreaux
Catherine E. Watson
RELEASE NO. 96-165
NASA Tests X-33 Cryogenic Fuel Tank Concepts
Researchers at NASA Langley Research Center, Hampton, Va., are conducting thermal-mechanical tests toward the development of a durable, lightweight cryogenic insulation system for possible use on future reusable launch vehicles (RLV).
The tests are being conducted in NASA Langley's Thermal Structures lab for Lockheed Martin, winner of NASA's Phase II contract, to develop the X-33 Flight Demonstrator Vehicle.
The objective of the X-33 is to demonstrate technologies that will be a trademark of a future reusable launch vehicle. The RLVs of the future will be single-stage-to-orbit vehicles that are intended to be cheaper and easier to operate than current space vehicles for space exploration payloads into the next century.
"These tests will give us the ability to verify, on a small scale, the operability of various cryogenic insulation systems," said NASA Langley's Kevin Rivers, who is conducting the tests for Lockheed. "We are able to verify that these systems will withstand combined thermal and mechanical loads in simulated mission of launch, orbit and reentry."
"We are also able to verify both the manufacturing techniques and health monitoring techniques," Rivers said, "and we can study the life cycle of the structure by repeating the tests simulating the projected number of missions the vehicle will fly."
Cryogenic refers to the production and effects of very low temperatures. The tests will allow researchers to demonstrate the viability of new and innovative cryogenic tank concepts at relatively low costs.
The tests consist of 25 cycles in which a one-foot by two-foot aluminum alloy panel, covered with cryogenic foam insulation, is cooled to -296 degrees Fahrenheit with liquid nitrogen. To simulate the heat of reentry, the panel and outer surface of the insulation will be heated to above temperatures expected during a reentry.
Fifteen thermal-mechanical tests will follow the 25 thermal cycles. The panel will be subjected to design loads that will simulate the launch-to-orbit and a reentry at the same time the simulated cooling/heating cycles are applied. Data from the results will be used in analyses for sizing the cryogenic insulation system on the X-33.
"We hope to give Lockheed Martin the data that will assist in determining the reusability and thermal-mechanical performance of the baseline cryogenic insulation system for the X-33," Rivers said. "One of the greatest challenges we face is finding the right material to withstand the extremes of temperature that this panel will have to endure. If results are positive, Lockheed is well on its way to having the material necessary to insulate fuel tanks for the RLV."
The testing is scheduled to continue through early October.
Photos, b-roll and interviews are available. Contact Ann Gaudreaux, Office of Public Affairs, 757-864-8150.
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