Flight 90 – The Plane that Accidentally Flew into Space

The North American X-15 rocket-powered aircraft project is known for bridging the gap between human-crewed flight within and beyond the bounds of Earth.

After successfully completing its initial test flights in the late 1950s, the X-15 became the first winged aircraft to reach the velocities of Mach 4, 5, and 6.

The X-15 was also the aircraft used for the first official NASA mission after it absorbed NACA in 1958.

But its most recognized mission was flight number 90.

A test flight conducted in 1963 by NASA and the Air Force was the first of two missions expected to pass the 100-kilometer height of the Karman line, set by the International Aeronautical Federation.

Flown by pilot Joseph Walker, this flight suffered from a few interesting deviations from the original plan.

But instead of ruining it, these unexpected divergences in the plan helped Walker ascend over the Karman line and become the first US civilian in space.

It also turned the X-15 mission into the first spaceflight of a spaceplane in aviation history.