Apollo 9 to land on the Moon; when the crews for Apollo 8 and 9 were swapped, their backup crews were also swapped. Since the rule of thumb was for backup crews to fly as prime crew three missions later, this put Neil Armstrong's crew (Borman's backup) in position for the first landing mission Apollo 11 instead of Pete Conrad's crew, who made the second landing on Apollo 12. Apollo 9 was the first space test of the complete Apollo spacecraft, including the third critical piece of Apollo hardware besides the command and service module and the Saturn V launch vehicle—the lunar
Apollo 1 the prime crew for a second Block I CSM flight, AS-205. NASA planned to follow this with an unmanned test flight of the LM (AS-206), then the third manned mission would be a dual flight designated AS-278 (or AS-207/208), in which AS-207 would launch the first manned Block II CSM, which would then rendezvous and dock with the LM launched unmanned on AS-208. In March, NASA was studying the possibility of flying the first Apollo mission as a joint space rendezvous with the final Project Gemini mission, Gemini 12 in November 1966. But by May, delays in making Apollo ready