Canceled Apollo missions planning their own circumlunar flight for December to upstage the Americans once again (see Zond program). McDivitt's crew—who had grown accustomed to working with LM-3 and preparing for its flight—was kept on the D mission which now became Apollo 9, while Borman's crew would fly the CSM lunar orbit mission on Apollo 8, and the E mission was canceled. The swap of crews was also decisive in who would be the first man to walk on the Moon. Pete Conrad was backup Commander for McDivitt's crew, and by the process of crew rotation, would have been in line for Commander
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