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
Apollo 6 spacecraft only entered the atmosphere at a speed of instead of the planned of a lunar return. However, this had been demonstrated on Apollo 4. Ten hours after launch, it landed from the planned touchdown point in the North Pacific Ocean north of Hawaii, and was lifted on board the USS "Okinawa". The S-IVB's orbit decayed three weeks later, and it reentered the atmosphere on April 25, 1968. Although Apollo 6 did not reach full translunar velocities in either direction, it was considered successful enough to fly astronauts on the next Saturn V, which in addition was tasked to send