Mutants in Orbit is an adventure and sourcebook for the After the Bomb and Rifts role-playing games, authored by James Wallis and Kevin Siembieda. It was released by Palladium Books in March 1992. The book deals with life of space colonies. The setting is on the same time scale as the After the Bomb and Rifts, only from the space colonies' point of view, but is in no way limited to that use.