Image taken from chase plane shows the rocket's out-of-control track. Photo: NASA-DFRC

The board investigating the X-43A mission loss on June 2 is continuing to meet at the Orbital Sciences Corp. facility in Chandler, Ariz., where they relocated on June 24. Orbital is where the Pegasus-derived booster rocket was built. The Pegasus was attached to the X-43A to provide the boost to a predetermined altitude.

The X-43A mission, first in a series of three, was lost moments after the X-43A and its booster rocket were released from the wing of the B-52 carrier aircraft. Following booster ignition, the combined booster and X-43A experienced structural failure, deviated from its flight path and was deliberately terminated.

Robert W. Hughes, the board chairman from Marshall Space Flight Center, has said that the likelihood of finding a single root cause of the mishap is still possible but becoming less probable. Hughes restated that the investigation team was working to fully understand the causal relationship and emphasized that the solution might involve several contributing causes rather than a single cause.

To date, the team has closed approximately 85 percent of the fault tree of several hundred possible or contributing causes. The remaining potential causes, most dealing with launch vehicle control, are being systematically investigated and evaluated.

The X-43A is designed to be the first scramjet-powered aircraft, capable of attaining speeds as high as Mach 10.

NASA's Langley Research Center at Hampton, Va., leads the X-43A program, with flight operations conducted by NASA Dryden Flight Research Center, Edwards, Calif. Micro Craft, Inc., of Tullahoma, Tenn., built the 12-foot-long X-43A vehicle. The mishap investigation team includes representatives from NASA centers including Dryden, Langley, Marshall (Alabama), Goddard (Maryland), Kennedy (Florida), plus all of the contractor elements.