NASA and the US Air Force Research Laboratory (AFRL) plan to firm up configuration of the X-43C hypersonic test vehicle in the next few weeks. The agency says the outcome of the investigation into the loss of the first X-43A could be known by the end of August.
The X-43A was destroyed on 2 June, seconds after release from NASA's B-52 carrier aircraft over the Pacific, during the first attempt to attain hypersonic flight with the combustion ramjet (scramjet) powered vehicle. NASA's mishap investigation team stresses the factors behind the accident "might involve several contributing causes rather than a single cause". However, it confirms that the "majority of the remaining faults are in the booster vehicle control arena".
Video of the failed mission points to a flight control system problem on the Orbital Sciences Pegasus booster rocket to which the X-43A was mated for the initial phase of the test. The agency is pressing ahead to fly the second X-43A vehicle in December, while a third is being prepared for a possible Mach 10 attempt in 2002.
Meanwhile, configuration studies of the larger X-43C are focused on a 4.9m (16ft) long vehicle powered by up to three scramjets mounted side-by-side beneath the belly. While the X-43A is powered by a gaseous hydrogen scramjet, the -43C will be fuelled with more than 450kg (1,000lb) of liquid hyrdocarbon. This will provide power for up to five minutes of continuous flight at speeds in excess of M5.
Source: Flight International
