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 21 21" lunar landing mission appears in three twenty-first-century works of fiction. The Apollo program used a Saturn V to launch the first manned test of the complete Apollo spacecraft, consisting of the Apollo Command/Service Module and a separate Apollo Lunar Module landing craft in a low Earth orbit, on the Apollo 9 mission. However, the original plan for this test would have used two launches of the smaller Saturn IB Earth-orbital launch vehicle: the first would launch the crew in the Command/Service Module, followed shortly by a second, unmanned launch of the Lunar Module, with which the crew would rendezvous