X-15 Flight 91 was a 1963 American crewed mission, and the second and final flight in the program to achieve sub-orbital spaceflight—a flight over 100 km in altitude. It was the highest flight of the X-15 program.
X-15 Flight 91 was a 1963 American crewed mission, and the second and final flight in the program to achieve sub-orbital spaceflight—a flight over 100 km in altitude. It was the highest flight of the X-15 program.