List of X-15 flights

Collectively, pilots and craft performed a total of 199 free flights after being carried aloft and then air launched from one of two modified B-52 mother ships.

John McKay was injured in (and recovered from, returning to active flight status) a landing accident which damaged the X-15-2, leading to its refurbishment as the modified X-15A-2.

Over thirteen flights, eight pilots flew above 264,000 feet or 50 miles, thereby qualifying as astronauts according to the United States definition of the space border.

All five Air Force pilots flew above 50 miles and were awarded military astronaut wings contemporaneously with their achievements, including Adams, who received the distinction posthumously following the flight 191 disaster.

Following this in 2005, NASA retroactively awarded its civilian astronaut wings to Dana (then living), and to McKay and Walker (posthumously).

Other chase pilots included future astronauts Michael Collins, Fred Haise and Jim McDivitt.

[8] On one occasion Chuck Yeager, former pilot of the X-15's predecessor X-plane the X-1, the first crewed craft to break the sound barrier, assisted as NB-52 co-pilot for an aborted flight.

The flight numbering conventions made no distinction between the original craft and its modified iteration; it continued to be designated "2".

Three X-15 spaceplanes performed 199 free flights.
X-15 pilots as of December 1965, left to right: Joe Engle , Bob Rushworth , John McKay , Pete Knight , Milt Thompson , and Bill Dana .