Supersonic combustion ramjet missile

During the period of 1962-1978, the Applied Physics Laboratory of Johns Hopkins University developed the technology for a family of missiles named SCRAM for use as fleet defense weapons. A novel class of multimodule fixed-geometry hypersonic inlets was designed and wind-tunnel models were built and tested at Mach numbers of 4-10 at angles of attack up to 15 deg. Injector and combustor development was carried out in direct connect test apparatus. Considerable effort was directed to the development and testing of a wide variety of storable, reactive liquid fuels, including boranes and aluminum alkyls. Many new testing techniques and diagnostic instruments were developed that are still key elements of scramjet test operations. The program culminated with the testing of the entire engine in free jets at Mach numbers of 57.3 and the design of a family of revised vehicle configurations that could exploit the full capability of the performance observed in the ground test program. This article presents the highlights of the technology program and references recently released documents. (Author)