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
Apollo 17 Apollo 17 Apollo 17 was the final mission of NASA's Apollo program. Launched at 12:33 a.m. Eastern Standard Time (EST) on December 7, 1972, with a crew made up of Commander Eugene Cernan, Command Module Pilot Ronald Evans, and Lunar Module Pilot Harrison Schmitt, it was the last use of Apollo hardware for its original purpose; after Apollo 17, extra Apollo spacecraft were used in the Skylab and Apollo–Soyuz programs. Apollo 17 was the first night launch of a U.S. human spaceflight and the final manned launch of a Saturn V rocket. It was a "J-type mission" which included three