Apollo 13 more immediate and visible warnings of anomalies. Because Apollo 13 followed the free-return trajectory, its altitude over the lunar far side was approximately greater than the orbital altitude on the remaining Apollo lunar missions. The Moon was almost at apogee during the mission (as it also was during the flights of Apollo 10 and Apollo 15), which also increased the distance from the Earth. The combination of the two effects ensures that Apollo 13 holds the absolute altitude record for a manned spacecraft, reaching a distance of from Earth on 7:21 pm EST, April 14, 1970. The A7L spacesuit intended
Apollo program Thirty-two astronauts were assigned to fly missions in the Apollo program. Twenty-four of these left Earth's orbit and flew around the Moon between December 1968 and December 1972 (three of them twice). Half of the 24 walked on the Moon's surface, though none of them returned to it after landing once. One of the moonwalkers was a trained geologist. Of the 32, Gus Grissom, Ed White, and Roger Chaffee were killed during a ground test in preparation for the Apollo 1 mission. The Apollo astronauts were chosen from the Project Mercury and Gemini veterans, plus from two later astronaut groups.