The Phantom Planet is a 1961 independently made American black-and-white science fiction film, produced by Fred Gebhardt, directed by William Marshall, that stars Dean Fredericks, Coleen Gray, Anthony Dexter, and Francis X. Bushman. The film was released in the U.S. by American International Pictures as a double feature with Assignment Outer Space.

Plot:
In 1980, the United States Air Force’s Space Exploration Wing has bases on the Moon, and it is on the eve of a mission to Mars. When another of its two-member crew Pegasus spacecraft mysteriously disappears, rumors begin circulating of space monsters and phantom planets. Captain Frank Chapman and his navigator Lt. Ray Makonnen are ordered to investigate.