Apollo–Soyuz Test Project made the Soviet Union's policy of détente official in his 1956 doctrine of peaceful coexistence at the 20th Congress of the Communist Party of the Soviet Union, the two nations seemed to be in perpetual conflict. Due to tense relations, space cooperation between the United States and the Soviet Union was unlikely in the early 1970s. On June 7, 1971, the USSR had launched the first piloted orbital space station, Salyut 1. Meanwhile, the United States had launched the Apollo 14 mission several months prior, the third spacecraft to land humans on the moon. Each side gave the other little
Lander (spacecraft) Surveyor. The U.S. manned Apollo Lunar Modules (since 1969) with rovers (since 1971) and Soviet unmanned late big landers (since 1969), Lunokhods (since 1970) and sample return missions (since 1970) used a rocket descent engine for a soft landing of astronauts and lunar rovers on the Moon. The Altair spacecraft, previously known as the "Lunar Surface Access Module" or "LSAM", was the planned lander for the Constellation program, prior to the cancellation of Project Constellation. Russia has plans for Luna-Grunt mission to return samples from the Moon by 2021. The Chinese Chang'e 3 mission and its Jade Rabbit rover landed