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
Third-party evidence for Apollo Moon landings was unknown for nearly 40 years but it was rediscovered in 2010 in photographs by the Lunar Reconnaissance Orbiter (LRO) and its retroreflector is now in use. Both the United States and the USSR had the capability to soft-land objects on the surface of the Moon for several years before that. The USSR successfully landed its first unmanned probe (Luna 9) on the Moon in February 1966, and the United States followed with Surveyor 1 in June 1966, but no unmanned landers carried retroreflectors before Lunokhod 1 in November 1970. Post-Apollo lunar exploration missions have located and imaged artifacts of