Between December 1968 and December 1972, 24 astronauts traveled to the Moon as part of NASA's Apollo program on nine missions. Twelve men walked on the moon during six successful two-man landing missions, six of them operated Lunar Roving Vehicles during the final three missions. Three men have visited the Moon twice; one orbited both times but did not land, while the other two landed once each. Aside from these 24 individuals, no one has ever been beyond low Earth orbit. The Moon has never been visited by a woman, although it has been orbited by a number of animals, including two tortoises and five mice.
Harrison Schmitt and Gene Cernan walked on the Moon on each of the Apollo 17 extravehicular activities (EVAs). Schmitt stepped out of the Apollo lunar module onto the Moon's surface after Cernan for their last EVA, making him the 12th and the last person to do so; when they re-entered the lunar module, Cernan stepped in last, after Schmitt, making him the last person to walk on the Moon. At 47 years and 80 days, Alan Shepard was the oldest person to walk on the Moon. At 36 years and 201 days, Charles Duke was the youngest. During the Apollo 13 mission, Jim Lovell and Fred Haise were supposed to walk on the Moon, but the lunar landing was canceled due to an explosion in the spacecraft service module on route to the Moon. Haise was slated to walk on the Moon again as commander of Apollo 19, but on September 2, 1970, both Apollo 18 and Apollo 19 were canceled.
