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 Applications Program the crew. The "Apollo Manned Survey Mission" proposed an Earth-observation science module also based on the LM ascent stage, and would also have been launched using a S-IVB vehicle into a high-inclination orbit. It was also proposed that a surplus Saturn V would launch a manned lunar survey mission to establish suitable sites for later manned landings. The wet workshop space station concept provided for a low-budget Earth orbiting station. The original plan, as proposed by Wernher von Braun, used the S-II stage as the primary structure of the station, with the area normally filled by the S-IVB stage replaced