X-15 Rocket Plane Sets World Altitude Record on This Day in 1963

On August 22, 1963, above the Mojave Desert, a rocket-powered aircraft called the X-15 climbed higher than any piloted plane had ever gone, crossing into the threshold where sky becomes space. Built by North American Aviation and flown in partnership with NASA, the craft was not merely chasing a record — it was gathering the hard-won knowledge that would teach humanity how to leave the atmosphere and return safely. In an era when the space age was still being invented flight by flight, the X-15 served as the bridge between what aviation had mastered and what spaceflight still required.