Moon by the Soviet Union's Luna 2, an unmanned spacecraft. The United States' NASA Apollo program achieved the only manned lunar missions to date, beginning with the first manned orbital mission by Apollo 8 in 1968, and six manned landings between 1969 and 1972, with the first being Apollo 11. These missions returned lunar rocks which have been used to develop a geological understanding of the Moon's origin, internal structure, and the Moon's later history. Since the Apollo 17 mission in 1972, the Moon has been visited only by unmanned spacecraft. Both the Moon's natural prominence in the earthly sky and
Colonization of the Moon In addition to its scientific returns, the Apollo program also provided valuable lessons about living and working in the lunar environment. The Soviet manned lunar programs failed to send a manned mission to the Moon. However, in 1966 Luna 9 was the first probe to achieve a soft landing and return close-up shots of the lunar surface. Luna 16 in 1970 returned the first Soviet lunar soil samples, while in 1970 and 1973 during the Lunokhod program two robotic rovers landed on the Moon. Lunokhod 1 explored the lunar surface for 322 days, and Lunokhod 2 operated on the Moon