Apollo Command/Service Module
Plans for outfitting an Apollo Command/Service Module (CSM) as a space rescue vehicle date back to November 1965 when North American Rockwell technicians conceived the possibility of a rescue mission for astronauts trapped in lunar orbit. After a rescue mission in Earth orbit was depicted in the 1969 film "Marooned", the company revived the concept in November 1970. Marshall Space Flight Center issued a formal Mission Requirements document on 17 May 1972, with subsequent revisions.