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
Docking and berthing of spacecraft the Soyuz spacecraft to add an internal transfer tunnel and used it to transport cosmonauts during the Salyut space station program with the first successful space station visit beginning on 7 June 1971, when Soyuz 11 docked to Salyut 1. The United States followed suit, docking its Apollo spacecraft to the Skylab space station in May 1973. In July 1975, the two nations cooperated in the Apollo-Soyuz Test Project, docking an Apollo spacecraft with a Soyuz using a specially designed docking module to accommodate the different docking systems and spacecraft atmospheres. Beginning with Salyut 6 in 1978, the Soviet Union