Moon landing the only country to have successfully conducted manned missions to the Moon, with the last departing the lunar surface in December 1972. After the unsuccessful attempt by the Luna 1 to land on the Moon in 1959, the Soviet Union performed the first hard (unpowered) Moon landing later that same year with the Luna 2 spacecraft, a feat the U.S. duplicated in 1962 with Ranger 4. Since then, twelve Soviet and U.S. spacecraft have used braking rockets to make soft landings and perform scientific operations on the lunar surface, between 1966 and 1976. In 1966 the USSR accomplished the first
Surveyor program time that NASA tested such systems in the challenging thermal and radiation environment near the Moon. Each Surveyor mission consisted of a single unmanned spacecraft designed and built by Hughes Aircraft Company. The launch vehicle was the Atlas-Centaur, which injected the craft directly into trans-lunar flightpath. The craft did not orbit the Moon on reaching it, but directly decelerated from impact trajectory, from 2.6 km/s relative to the Moon before firing retrorockets to a soft landing about 3 minutes 10 seconds later. Each craft was planned to slow to about 110 m/s (4% of speed before retrofire) by a main