X-15
The [B]North American X-15[/B] was a hypersonic rocket-powered [[aircraft]] operated by the United States Air Force and the National Aeronautics and Space Administration (N.A.S.A.) 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 later 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 [b]Mach 6.72[/b] at 102,100 feet (31,120 m), a speed of 4,520 miles per hour (7,274 km/h), has remained unchallenged as of May 2017.
x-15