In October 1945, the Army Technical Services Command asked aeronautical corporations in the United States to design a guided missile. Consolidated Vultee proposed the MX-774, which would become the Atlas Intercontinental Ballistic Missile. North American Aviation proposed the MX-770, the Navaho -- a 500-mile-range missile with greater accuracy than the German-built V-2.
Although the Air Force canceled the Navaho program in 1957, in its 10 years of existence, the Navaho made many key technological breakthroughs. The X-10 Navaho test drone was the first turbojet-powered vehicle to reach Mach 2 and the first aircraft to fly a complete mission under inertial (computerized) guidance. Its booster engine set a record by producing 405,000 pounds of thrust. The X-10 was the only missile to be classified as an "X" plane and completed more than 20 flights. Data from these flights led to the development of the SM-64 Navaho ground-to-ground missile system.
Phase two of the nuclear Navaho development program was the G-26 drone missile, which would prove the vertical launch system. The G-26 required the development of the largest ramjet engines built, an auxiliary power unit to power the missile's electronics and hydraulics, and a more effective autonavigator unit, the N-6 or NAVAN (North American Vehicle Auto Navigation), built by North American's Autonetics Division.
The Navaho program was canceled in July 1957 when, after extensive testing at Cape Canaveral, Fla., the Atlas ICBM was chosen over winged missile designs. On July 13, 1998, exactly 41 years from the day when the Navaho was canceled, and after two years restoring the X-10, the Air Force Space and Missile Museum rolled out the only Navaho missile in existence and placed it on display.