The mission liftoff is depicted by stock NASA footage of three different rocket takeoffs; SA-201, SA-202, and a third, unidentified Atlas rocket. Several rocket scenes of the landing and second takeoff make use of the Atlas rocket footage.
This was the first feature made at the Studio City Complex in Miami, Florida.
Co-Star Nick Adams died in February, 1968, almost six months before the completed film was released that July.
Darren McGavin would return to Mars as an astronaut in The Martian Chronicles eleven years later.
The first film listed under Sagittarius Productions. Sagittarius Productions, Inc. was an American independent film production and international sales company founded in 1967 by Canadian businessman Edgar Bronfman Sr., who was also then-investor in Metro-Goldwyn-Mayer (MGM),