The North American SM-64 Navaho was a supersonic intercontinental cruise missile project built by North American Aviation. The program ran from 1946 to 1958 when it was cancelled in favor of intercontinental ballistic missiles.
The Navaho program began as part of a series of guided missile research efforts started in 1946. Designated MX-770, the original intent of the program was the development of a winged V-2 missile that could deliver a nuclear (fission) warhead over a distance of 500 miles (800 km). This was more than double the range of the V-2 as well as having a larger payload. Design studies showed the promise of still greater ranges and by 1950 the vehicle had evolved from a 500-mile (800 km) ground launched winged V-2, to a 1,000-mile (1,600 km) range ramjet powered winged V-2, to a 1,500-mile (2,400 km) air-launched, ramjet-powered, winged V-2 (actually designated XSSM-A-2), to finally a 3,000-mile (4,800 km) plus rocket boosted ramjet powered cruise missile. The design evolution finally ended in July 1950 with the issuing by the Air Force of Weapon System 104-A. Under this new requirement the purpose of the program was the development of a 5,500-mile (8,900 km) range nuclear missile.
