X-33's innovative aerospike engine undergoes its longest test to date at 100 percent power, exceeding the previous test by 30 seconds. Photo: NASA/SSC

The innovative aerospike engine that will power the X-33 Advanced Technology Demonstrator reached a significant milestone at NASA's John C. Stennis Space Center in south Mississippi on February 3 with its longest test to date and the first demonstration of the engine's full thrust vector control.

A NASA/Boeing Rocketdyne team tested the XRS-2200 Linear Aerospike Engine for 125 seconds. This 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 vector control. The test also demonstrated engine operation at varied power levels and tested different mixture ratios.

Lockheed Martin's X-33 vehicle will use thrust vector control to steer itself in flight. This capability allows vehicle designers to avoid the weight and complexity of engine gimbaling mechanisms, supporting the push for aircraft-like operations.

Initial test data indicates satisfactory engine performance throughout the test.

"The Stennis and Boeing/Rocketdyne test team continues to produce outstanding results in yet another critical milestone in full-power, single-engine testing. This one test ran the engine longer than all previous seven tests combined," said NASA's Dr. Donald Chenevert, X-33 assistant project manager at Stennis Space Center.

Steam billows from the Stennis Space Center teststand where the aerospike engine is fired. Photo: NASA/SSC

The XRS-2200 engine was developed and assembled by Boeing Rocketdyne Propulsion & Power, Canoga Park, Calif. The engine will power the X-33, a half-scale, sub-orbital technology demonstrator of Lockheed Martin's proposed, commercial reusable launch vehicle called VentureStarTM. The X-33 is being developed in partnership with NASA and Lockheed Martin Aeronautics Company -- "the Skunk Works" -- Palmdale, Calif. Marshall Space Flight Center in Huntsville, Ala., manages the X-33 program for NASA.

Once testing of the first of the program's four engines has been successfully completed, two flight engines will be tested. After successful flight acceptance test of the engines, the two flight engines will be shipped to Lockheed Martin Aeronautics Company in Palmdale to be mounted on the X-33 vehicle in preparation for future flight demonstrations.