Apollo 8 yet ready to make its first flight. Astronaut Jim McDivitt's crew, who were training to fly the first lunar module flight in low Earth orbit, became the crew for the Apollo 9 mission, and Borman's crew were moved to the Apollo 8 mission. This left Borman's crew with two to three months' less training and preparation time than originally planned, and replaced the planned lunar module training with translunar navigation training. Apollo 8 took 68 hours (almost three days) to travel the distance to the Moon. The crew orbited the Moon ten times over the course of 20 hours, during
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