History of Ramjet and Scramjet Propulsion Development for U.S. Navy Missiles

this article is to summarize the evolution and development of ramjet engines (and variants thereof) as propulsion systems for missiles flying at supersonic (or faster) flight speeds that have been supported by the U.S. Navy since World War II. Reference 1 provides a discussion on the details of the types of engines under discussion, along with their limitations, and a historical perspective on the evolutionary timescale of ramjets, scramjets, and mixed-cycle engines. Reference 2 presents a similar discussion for U.S. Air Force--developed systems. In this article we summarize programs to develop surface-launched and air-launched subsonic combustion ramjets and scramjets. Table 1 shows the evolutionary history of all of the ramjet and scramjet engine and vehicle concepts and systems included in these discussions. The names, engine types, dates, performance, system constraints, etc., for each are presented. (Some information is not given for reasons of security.) The U.S. Navy has supported and developed a substantial technology base, including a variety of ramjets. This technology base, however, is not nearly as substantial for scramjets and their derivatives. A number of these ramjet engines and ramjet-powered weapon concepts have been flight tested, but none at hypersonic speeds. Only one U.S. Navy ramjet system has ever become operational (the Talos), and it is still being used as a target today (Vandal). SURFACE-LAUNCHED RAMJET DEVELOPMENT