A linear aerospike engine is removed from its test stand following successful completion of single-engine testing at the Stennis Space Center, Miss. Preparations are now underway for dual-engine testing. Photo: NASA

Preparations are under way at NASA's John C. Stennis Space Center near Bay St. Louis, Miss., for the final phase of testing to qualify the innovative Linear Aerospike engine that will power the experimental X-33 rocket plane being developed by a Lockheed Martin-led industry team and NASA.

Having recently completed a successful series of single-engine tests, the engine has been removed from the Stennis test stand by a team from NASA and the Rocketdyne Propulsion & Power unit of The Boeing Company. The stand is now being modified to accommodate two engines for simultaneous firings in their flight configuration. This phase of the program is scheduled to begin late this year. Following successful completion of dual-engine testing, these engines will be shipped to Palmdale, Calif., where they will be installed in the X-33 vehicle.

During the first phase of testing, the engine accumulated more than 1,500 seconds of operation -- the equivalent of approximately seven X-33 flights.

"We are amazed and delighted at how smoothly the test program has gone so far," said Mike McKeon, program manager for the XRS-2200 Linear Aerospike Engine at Boeing Rocketdyne. "We conducted 14 tests and accumulated a wealth of vital data without breaking any hardware. For an engine development program of this magnitude and complexity, that is simply amazing."

"Few new, much less innovative, engines even get to full power in so few tests," added NASA's Dr. Donald Chenevert, X-33 Project Manager at Stennis Space Center. "We met or exceeded a number of significant objectives during the first phase of the program, " said Chenevert. These milestones include: starting the engine under various conditions, operating at and throttling between various power levels, operating at various fuel and oxidizer mixtures, and varying the thrust across the engine.

The linear aerospike engine is lowered from its test stand. Photo: NASA

For the next phase of testing, two engines will be mated together and operated in X-33 flight configuration. Approximately nine dual-engine tests are planned. This phase of testing will verify the seal between the two engines; dual-engine start, stop and operational parameters; and the ability for the engines to control the X-33's direction of flight by varying the thrust from side to side and engine to engine. The testing will also verify the ability of one engine's turbo-machinery to power both engines should a set of turbo-machinery fail during flight.

"We are proud of the NASA/industry team that has so effectively brought this unique new engine to this significant milestone," said Gene Austin, NASA's X-33 Program manager with the Marshall Space Flight Center. "The hardware worked well in this first test series, and we are eager to see how well it performs in the dual engine testing. This engine has the potential to revolutionize our nation's space launch capabilities. It is just one of many cutting edge technologies the X-33 program is demonstrating."

The XRS-2000 engine was developed by Boeing Rocketdyne at its Canoga Park, Calif. Final engine assembly was done by the NASA/Boeing Rocketdyne team at Stennis Space Center.

Two aerospike engines will power the X-33, a half-scale, suborbital technology demonstrator of Lockheed Martin's proposed commercial reusable launch vehicle called VentureStarTM. The X-33 is being developed as a joint government/industry partnership under a cooperative agreement between NASA and Lockheed Martin Aeronautics Company in Palmdale, Calif. Marshall Space Flight Center in Huntsville, Ala., manages the X-33 program for NASA.