Moon landing the first Soyuz flight in 1967, the co-ordination of the Soviet Moon landing program quickly unraveled. The Soviets built a landing craft and selected cosmonauts for the mission that would have placed Aleksei Leonov on the Moon's surface, but with the successive launch failures of the N1 booster in 1969, plans for a manned landing suffered first delay and then cancellation. A program of automated return vehicles was begun, in the hope of being the first to return lunar rocks. This had several failures. It eventually succeeded with Luna 16. But this had little impact, because the Apollo 11 and
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