X-33's innovative aerospike engine undergoes a similar firing test on February 3. Photo: NASA/SSC

The 10th of 14 planned single-engine tests of the linear aerospike engine for the X-33 Advanced Technology Demonstrator was conducted at the Stennis Space Center in Bay St. Louis, MS, on March 9.

The test ran approximately 75 of a planned 220 seconds. Early shutdown was attributed to a change in the engine's controlling software. Initial inspections have revealed no significant damage to the engine or supporting equipment, and the next test is slated in about a week.

Shut-down of the engine, at 75.44 seconds, was attributed to missing a qualification limit on fuel pump discharge pressure in new mixture ratio control software during the first attempt at a 30 percent per second throttling rate from 100 percent to 72 percent power level. All previous nine tests have gone full duration.

Objectives planned for the first 75 seconds of the test were all met including throttle rate, thrust vector control, power level and mixture ratio. The next test will repeat parts of this test to pick up the remaining objectives.

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 VentureStar.

The X-33 is being developed in partnership with NASA and Lockheed Martin Aeronautics Company in Palmdale, Calif. Marshall Space Flight Center in Huntsville, Ala., manages the X-33 program for NASA.