North American X-10 The turbojet-powered X-10 tested flight characteristics and guidance, navigation and control systems for the planned SM-64 Navaho. The Navaho was intended to be a ramjet-powered, nuclear-armed cruise missile launched by rocket boosters. North American built 13 X-10s (10 of which were test flown), and the first X-10 flight occurred in October 1953. Although accidents destroyed several X-10s, the test program proved to be successful. One X-10 flew at Mach 2.05, a remarkable achievement for the time. In 1957, however, the Navaho program was cancelled as Intercontinental Ballistic Missile (ICBM) technology matured. The remaining X-10s were used to support the XB-70 program and as targets for Surface-to-Air Missiles (SAMs) then in development. The museum’s X-10 is the only one still in existence. TECHNICAL NOTES: Engines: Two Westinghouse XJ40s of 10,000 lbs. thrust each (with afterburner) Maximum speed: 1,300 mph Range: 400 miles Service ceiling: 45,000 feet Weight: 40,000 lbs. Click here to return to the Research & Development Gallery.