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
Canceled Apollo missions Apollo–Soyuz Test Project. Skylab 5 would have been a short 20-day mission to conduct scientific experiments and boost Skylab into a higher orbit. Brand, Lind, and William B. Lenoir (science pilot) would have been the crew. Two complete Saturn Vs went unused after the Apollo program, SA-514 and SA-515, as well as the third stage of the SA-513. SA-513 was the launch vehicle originally planned for the Apollo 18 mission, which was used to launch Skylab. The last complete, unflown Saturn IB, SA-209, kept on standby for a possible Skylab Rescue mission, is on display in the Rocket Garden of