Photographed in color by Color Corporation Of America; when sold to television in 1956, most prints and broadcasts were in black & white. The 35MM color master used for the DVD release, occasionally shown on Turner Classic Movies, shows a lot of wear and a few splices, particularly at the reel changes, but may be the best that has survived.
Cinematographer Stanley Cortez was fired and replaced (by Joseph F. Biroc) after clashing with director Herbert L. Strock, but still retained screen credit.
William Lundigan would go on to star in the similar TV series Men Into Space in which both Robert Karnes and James Best would make guest appearances.
This is the second of three films in producer Ivan Tors' "OSI" series. The scientists are taken to the "Snake Mountain Proving Grounds, operated by the Office of Scientific Investigation," according to Dr. Dryden. Dr. Stanton's desk nameplate indicates he is "Chief of Investigations."
Actually, when the scientists arrive, they are told that the base is operated by OSI. Also, the jeeps seen at the beginning have OSI stenciled on the hoods.