Stennis Space Center, Miss., has successfully completed a critical initial test in a three-part series for a Space Launch Initiative (SLI) test program of the Electro-Mechanical Actuator (EMA) technology used on the former X-33 program's Linear Aerospike XRS-2200 flight engine set. The July 12 test was a "start-sequence" test and went the full scheduled duration of 5.32 seconds.

Linear Aerospike XRS-2200 flight engine is fired for a Space Launch Initiative test. Photo: NASA

The test was a unique opportunity for NASA to effectively gain valuable experience and data from existing commercial technology.

EMAs electronically regulate the amount of propellant (fuel and oxidizer) flow in the engine. The technology is a potential alternative and improvement to the older hydraulic-fluid systems currently used by the aerospace industry to drive and control critical rocket engine valves.

According to NASA's Garry Lyles, Space Launch Initiative Propulsion Program Office manager at Marshall Space Flight Center, Huntsville, Ala., the EMA technology is of interest to SLI because all engine concepts being considered for the program use EMAs.

"SLI's primary focus is on technology development for concepts that would be able to dramatically reduce cost and improve safety and reliability of launching payloads for NASA, commercial and military missions," Lyles said. "Since the engine was already in a test stand at Stennis, taking advantage of the dual aerospike flight engine set already in the A-1 test stand was too great of an opportunity to pass up."

According to NASA's Dr. Don Chenevert, EMA project manager at Stennis, the initial test will be followed with a 25-second test at 80 percent power-level. The third test is scheduled for 100 seconds and will demonstrate relevant engine operations and show how the EMA control system works under actual thermal, hydraulic and stress loads.