Alliant Techsystems (ATK) is developing a Mach 5 scramjet-powered cruise missile, according to an article in Jane’s Defense Weekly. ATK officials told Jane’s that the missile will have a range of 600 nm and carry a 250 lb warhead. The missile is being developed with internal ATK funds, but the company is hoping to eventually get a contract from either the Pentagon or NASA. The scramjet will be designed for fixed-point operation at Mach 5, which will greatly simplify the design compared to other proposed scramjets, which must operate over a range of Mach numbers. The missile will use JP8 military jet fuel. The missile will be boosted to Mach 5 by a solid-fueled rocket. ATK developed NASA’s X-43 hypersonic research aircraft, which flew successfully on March 27, 2004, the first time an airbreathing scramjet powered aircraft has flown freely. The unpiloted vehicle's scramjet used hydrogen fuel for its 10 second flight, reaching a test speed of Mach 7. ATK built both the vehicle and the scramjet engine. In a subsequent flight on 16 Nov 04, the X-43 achieved a speed of Mach 9.8. ATK’s proposed scramjet-powered missile comes at a time when two other scramjet missiles are under development by the Pentagon. Aerojet has been conducting ground tests of its HyFly (Hypersonic Flight) engine at simulated speeds between Mach 3.5 and 6.5. Aerojet is designing and building the hypersonic engine for Boeing Phantom Works, who will integrate the engines into the HyFly flight test vehicles. The DARPA-sponsored HyFly program will demonstrate a Mach 6 vehicle with a range of 600 nautical miles. Like ATK’s proposed scramjet missile, the Aerojet scramjet uses liquid hydrocarbon fuel. Pratt & Whitney and Boeing Phantom Works are developing the Endothermically Fueled Scramjet Engine Flight Demonstrator (EFSEFD), also known as the Scramjet Engine Demonstrator - WaveRider (SED-WR), for the Air Force Research Laboratory (AFRL). Flight tests will begin in the 2008 time frame. Initially propelled by a solid rocket booster, the scramjet demonstrator will take over at approximately Mach 4.5 where it then will accelerate to flight speed between Mach 6.0 to 7.0. Previously, Pratt & Whitney, under an AFRL contract, ground tested the world's first flight-weight, actively cooled, hydrocarbon-fueled scramjet engine. It used standard JP-7 fuel to both cool engine hardware and fuel the engine's combustor. ATK expects to conduct a flight test of its proposed scramjet missile within the next 3 years. -- 28 Jul 05