GUY NORRIS / LOS ANGELES
NASA's second attempt to fly an X-43A air-breathing hypersonic test aircraft is set for mid-December. The first effort ended with the destruction of the vehicle over the Pacific on 2 June 2001.
Details of the test and of a captive carry test set for 15 November on NASA's Boeing B-52 emerged as the agency awarded a $150 million contract to Tennessee-based Allied Aerospace Industries for three follow-on X-43C demonstrators. The three vehicles will demonstrate free flight of a scramjet-powered aircraft with acceleration capability from Mach 5 to 7, as well as operation of the joint Pratt & Whitney, US Department of Defense and NASA-developed hydrocarbon fuel-cooled scramjet.
The placing of the order before the X-43A test is seen as a major confidence booster for the hypersonic effort, which includes the US Air Force's HyTech scramjet development programme and NASA's related X-43 research. NASA says the renewed impetus behind the X-43C is due partly to "more of a USAF participation" than was the case with the X-43A. Concerns have been expressed over the future of X-43C, but should a second hypersonic failure occur in December, USAF's interest in pushing flight tests of scramjets is more than compensating.
The USAF is accelerating scramjet concept tests and plans to develop a single-engined hypersonic demonstrator (SED) for flight in 2006, one year before the first X-43C. The SED will use the same P&W scramjet engine as the X-43C, but with one propulsion system rather than three. The SED version will have a simpler fixed-geometry inlet demonstrator test engine version of the variable inlet GDE-2 dual-mode scramjet derivative aimed at the X-43C.
The Allied Aerospace team on X-43C includes P&W, Boeing Phantom Works and Virginia-based RJK Technologies. For the demonstrations, an Orbital Sciences Pegasus rocket booster will be air-launched from the B-52 to boost the X-43C to Mach 5 at 80,000ft (24,400m). The X-43C will separate and accelerate to Mach 7 under its own power and autonomous control.
Source: Flight International
