X-15 was released 1961. Inspired by the experimental X-15, the first piloted aircraft to achieve hypersonic flight, as well as the first to achieve flight above the stratosphere. The X-15 was only one in a long series of X-planes.

The film was a dramatization of the rocket plane's development program, which was among the very earliest NASA programs; inherited from NACA (the predecessor of NASA). Featuring a cast of characters, with pilots, flight engineers, crew and their families, the plot line was an imaginary story depicted around real events.

X-15 starred David McLean, Charles Bronson, James Gregory and Mary Tyler Moore (her first film role). The debut of Richard Donner, as director, with narration by James Stewart.