Flight 150 of the North American X-15 was a test flight conducted by NASA and the US Air Force in 1965. Piloted by John B. McKay it reached an altitude of 90.0 km. September 28, 1965 at 18:08 UTC · Launch Successful North American X-15 — United States Air Force, to Suborbital Edwards Air Force Base, Air launch to Suborbital flight Crew: John B. McKay Program: X-15 Data: Launch Library 2, The Space Devs. Image via The Space Devs.