The aerospike engine was developed and assembled by Boeing Rocketdyne Propulsion & Power in Canoga Park, Calif. The test firing of this new engine marks the first time a linear aerospike engine will be tested at Stennis Space Center.

The engine will power the X-33, a half-scale technology demonstrator of a full-scale, commercially-developed, reusable launch vehicle, called VentureStarTM, that is scheduled for development early in the next century.

The X-33, scheduled to begin flying in summer 2000, is being developed under a cooperative agreement between NASA and Lockheed Martin Skunk Works of Palmdale, Calif. Marshall Space Flight Center in Huntsville, Ala., manages the X-33 program for NASA.

Stennis personnel will conduct a total of 41 test firings on four engines -- two test engines and two flight engines. The first 25 firings, scheduled to begin in September, will involve two flight engines and one test engine, each tested individually.

The first six tests on the test engine will address engine ignition and start sequence development. These tests are planned to be five seconds or less in duration.

Upon successful completion of those initial tests, eight more tests are planned at a maximum of 250 seconds in duration to verify engine performance at various mixture ratios and power levels, as well as demonstrate thrust vector control. Planned total test duration on the first test engine is 1,142 seconds.

Once the first engine has been successfully tested, two flight engines will be tested for a total of 11 tests and 1,042 seconds in duration. After successful flight acceptance test of the engines, the two flight engines will be shipped to Lockheed Martin Skunk Works in Palmdale to be mounted on the X-33 near the end of 1999.

Beginning in January 2000, a dual-engine arrangement, assembled in flight configuration, will be tested in the south Mississippi facility's A-1 test stand. Sixteen dual-engine test firings are planned for a total of 2,646 seconds in duration.

Completion of the aerospike engine test program is scheduled for summer 2000.

During its flight tests in 2000 from Southern California, the X-33's two onboard linear aerospike engines will run for 175 to 195 seconds before reaching main engine cutoff.

After landing, the X-33 will be returned to its launch site, where the completely reusable vehicle and its two onboard engines will be quickly checked out and readied for the next flight.