In August 1998 the Boeing Phantom Works was awarded a $10 million 18-month contract to design and conduct developmental tests of two different hypersonic vehicle concepts, each capable of cruise speeds of more than Mach 6. One vehicle has a long, wide, flat shape, which will allow it to ride on its own shock wave for reduced drag. This "waverider" concept will be propelled by a supersonic ramjet (scramjet) engine currently being developed by Pratt & Whitney for the U.S. Air Force. The other vehicle has a more traditional cylindrical shape. It will use a dual-combustion ram/scramjet engine originally developed by Johns Hopkins University Applied Physics Laboratory for the US Navy but now being adapted for ARRMD by Aerojet.The $50 million Phase 2 may follow successful completion of Phase 1, through a contract option to assemble flight vehicle(s) and conduct flight demonstration testing. If ARRMD performance and affordability objectives can be demonstrated under the first phase of the agreement, DARPA plans to continue with a 30-month producibility and flight test demonstration program with one or both of the hypersonic concepts. A hypersonic missile flight demonstration is planned in the program in 2001.
A successful ARRMD program would allow the Department of Defense to pursue an engineering and manufacturing development program as early as 2004 and have an operational missile in the US Navy and Air Force fleets by 2010.
The Air Force Hypersonic Technology (HyTech) Program has put programs in place to develop the technologies necessary to demonstrate the operability, performance and structural durability of an expendable, liquid hydrocarbon fueled scramjet system that operates from Mach 4 to 8. This program will culminate in a flight type engine test at representative flight conditions. The hypersonic technology base that will be developed and demonstrated under HyTech will establish the foundation to enable hypersonic propulsion systems for a broad range of air vehicle applications from missiles to space access vehicles. Pratt & Whitney is developing the technology for hypersonic components and engines. A supersonic combustion ramjet (scramjet) database was developed using hydrogen fueled propulsion systems for space access vehicles and serves as a point of departure for the current development of hydrocarbon scramjets.