By 1953, six years after the Bell X-1 first went supersonic, that airplane and others were routinely flying at more than twice the speed of sound. On December 17, 1953the 50th anniversary of the Wright brothers first powered flight at Kitty HawkMajor Yeager sat down at the Pentagon for an informal press briefing to discuss his own Mach 2.43 flight in the X-1 five days earlier. Video: Department of Defense, Courtesy National Archives and Records Administration