As part of the Apollo program by NASA, 24 astronauts flew 9 missions to the Moon between December 1968 and December 1972. During six successful two-man landing missions, 12 men walked on the lunar surface, six of whom drove Lunar Roving Vehicles as part of the last three missions. Three men have been to the Moon twice, one only orbited both times, while the other two landed once apiece. Apart from these 24 men, no human being has gone beyond low Earth orbit. No woman has been to the Moon, but a number of animals have orbited it, including two tortoises and five mice.