https://en.wikipedia.org/wiki/North_American_X-15During 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. The only Navy pilot in the X-15 program never took the aircraft above the requisite 50 mile (80 km) altitude and thus never earned astronaut wings.