Shot in 11 days.

The original green tint of the "lost continent" sequences was not reproduced for television prints of the film (the sequences were shown in black-and-white instead), and it was not until well over 30 years after the film's initial release that the tint was restored for home video in the late 1980s.

The opening shot of the White Sands Missile Base, and some of the rocket scenes, were lifted from Rocketship X-M (1950) which, like this film, had also been released by Lippert Pictures.

Mentioned in Stephen King's "The Dark Tower VII: The Dark Tower" as a movie that scared the character Jake Chambers as a child and is used against him in a mind-trap as his deepest fear.

Some sequences were originally tinted green on the original release prints.

The 20-minute rock climbing sequence was mercilessly skewered on Mystery Science Theatre 3000 (1988).

Lt. Wilson often has a cigarette in his mouth, but it is never lit.