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 14 his trip aboard Apollo 14. He is the only astronaut from Project Mercury (the original Mercury Seven astronauts) to reach the Moon. Another of the original seven, Gordon Cooper, had (as Apollo 10's backup commander) tentatively been scheduled to command the mission, but according to author Andrew Chaikin, his casual attitude toward training, along with problems with NASA hierarchy (reaching all the way back to the Mercury-Atlas 9 flight), resulted in his removal. The mission was a personal triumph for Shepard, who had battled back from Ménière's disease which grounded him from 1964 to 1968. He and his crew were