These mean earned astronaut wings without launching on a rocket. Here’s how.
The X-15 was a groundbreaking aircraft that pushed the boundaries of human flight. It was designed to test the limits of hypersonic flight, reaching speeds of over Mach 6. Between 1959 and 1968, the X-15 flew 199 missions, setting numerous records for speed and altitude.
Now, here’s the catch: while it didn’t launch into space on a rocket, it did fly so high that it crossed the Air Force’s definition of space—50 miles up. This meant that eight of the X-15 pilots were officially designated as astronauts, even though they never left the planet in a traditional rocket ship.
