Describes how the X-15 Aircraft was designed and built by North American Aviation. Engineered to be the worlds fastest aircraft, the North American X-15 was a hypersonic rocket-powered aircraft operated by the USAF and the National Aeronautics and Space Administration (NASA) as part of the X-plane experimental aerospace projects. The X-15 set speed and altitude records in the 1960s, reaching the edge of outer space and returning with valuable data later used in aircraft design. As of September 2015, the X-15 holds the official world record for the highest speed ever recorded by a manned, powered aircraft. It would ultimately reach a top speed of 4,520 miles per hour (7,274 km/h), or Mach 6.72.