The North American X-15 was a rocket-powered aircraft that flew at hypersonic speeds and almost achieved spaceflight. | Sunday Roast

The X-15 was a joint hypersonic research program with NASA, the Air Force, the Navy, and North American Aviation, Inc. It was developed to provide in-flight data on aerodynamics, structures, flight controls, and the physiological aspects of high-speed, high-altitude flight. The X-15 proved that piloted high-performance aircraft can be flown in space, and identified 25 specific accomplishments which contributed to the development of the Mercury, Gemini, and Apollo manned spaceflight programs, and