First flown on Oct. 20, 1952, the needle-nosed Douglas X-3 Stiletto was designed to explore aerodynamic Douglas X-3 Stilettoairframe heating at Mach 2 plus. Jet propulsion technology of the 1950s, however, could not provide ad-equate super-sonic performance. After 51 flights the program ended. Its unique configuration did contribute to several follow-on aircraft, including the thin-winged F-104.