On this day in space! Aug. 22, 1963: X-15 sets world altitude record

On August 22, 1963, U.S. Air Force Captain Joe Walker achieved a remarkable feat by flying the X-15 rocket plane higher than any pilot had flown before. He reached an altitude of over 67 miles (108 kilometers), just a few miles above the edge of space. The 11-minute flight saw Walker experience about five minutes of weightlessness.

This was the second and final suborbital spaceflight of the X-15 program, which Walker piloted both times, becoming the first person to go to space twice. The X-15 #3, the space plane he flew in, also became the first reused spacecraft to return to space. The flight was part of an X-15 program that helped engineers learn how humans and vehicles function at hypersonic speeds and during transitions between the atmosphere and space.

The insights gained from the flights informed later NASA programs, including Mercury, Gemini, and Apollo, and later the Space Shuttle's development. Walker's high-altitude flight also showcased the concept of reusability, a principle that became crucial for future space exploration, most notably with NASA's Space Shuttle and SpaceX's Falcon 9 rocket.