The North American X-15 is a hypersonic rocket-powered aircraft which was operated by the United States Air Force and the National Aeronautics and Space Administration (NASA) as part of the X-plane series of experimental aircraft. The X-15 set speed and altitude records in the 1960s, crossing the edge of outer space and returning with valuable data used in aircraft and spacecraft design. The X-15's highest speed, 4,520 miles per hour, was achieved on 3October 1967, when William J. Knight flew at Mach6.7 at an altitude of 102,100 feet (31,120 m), or 19.34miles. This set the official world record for the highest speed ever recorded by a crewed, powered aircraft, which remains unbroken.
The X-15 pilots clown around in front of the #2 aircraft. From left to right: Joseph Engle, Robert Rushworth, John McKay, William Knight, Milton Thompson, and William Dana.
North American X-15A-2 with external fuel tanks (150806-F-IO108-005)
X-15 contrail after launch
The X-15 pilots clown around in front of the #2 aircraft. From left to right: Joseph Engle, Robert Rushworth, John McKay, William Knight, Milton Thompson, and William Dana.
North American X-15 at the Smithsonian Institution National Air and Space Museum
Robert Michael White in North American X-15
North American X-15 at the Smithsonian Institution National Air and Space Museum
North American X-15 at the Smithsonian Institution National Air and Space Museum