North American X-15

The North American X-15 was a hypersonic rocket-powered aircraft operated by the USAF and NASA as part of the X-plane series of experimental aircraft. The X-15 set speed and altitude records in the 1960s, reaching the edge of outer space and returning with valuable data used in aircraft and spacecraft design. The X-15's official world record for the highest speed ever recorded by a manned, powered aircraft, set in October 1967 when William J. "Pete" Knight flew at 4,520 miles per hour, or Mach 6.72, and has remained unchallenged as of 2016.

During the X-15 program, 13 flights by eight pilots met the Air Force spaceflight criterion by exceeding the altitude of 50 miles (80 km), thus qualifying these pilots as being astronauts. The Air Force pilots qualified for astronaut wings immediately, while the civilian pilots were eventually awarded NASA astronaut wings in 2005, 35 years after the last X-15 flight.

First flight: 8 June 1959

Smithsonian Air & Space Museum, Nov 2016
Photo 434

North American X-15

Smithsonian Air & Space Museum, Nov 2016
Photo 448