The X-15 was the first USAF and NASA project for manned spaceflight. Its goal was to explore ballistic flight, winged reentry, and gliding recovery from space. It was a stepping stone to later developments that would lead to manned orbital spaceflight. In the joint X-15 hypersonic research program that NASA conducted with the Air Force, the Navy, and North American Aviation, Inc., the aircraft flew over a period of nearly 10 years and set the world's unofficial speed and altitude records of 4,520 mph (Mach 6.7) and 354,200 ft in a program to investigate all aspects of piloted hypersonic flight. …