Apollo 11 the CMP on the Apollo 8 crew, began experiencing trouble with his legs. Doctors diagnosed the problem as a bony growth between his fifth and sixth vertebrae, requiring surgery. Lovell took his place on the Apollo 8 crew, and, when Collins recovered, he joined Armstrong's crew as CMP. In the meantime, Fred Haise filled in as backup LMP, and Aldrin as backup CMP for Apollo 8. Apollo 11 was the second all-veteran crew on an American mission, the first being that of Apollo 10. The next was STS-26 in 1988. The backup crew consisted of Lovell as Commander, William Anders
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