Salyut 6

Salyut 6, also known as DOS-5, was a Soviet orbital space station and the eighth station of the Salyut programme. It was launched on 29 September 1977 by a Proton-K rocket and was the first of the second generation of space stations. Its main advance was a second docking port, which let two craft visit at once, so resident crews could be resupplied by uncrewed Progress ships and receive short visiting expeditions without leaving the station. Six long-term resident crews were supported by ten visiting crews, many of them international cosmonauts from Warsaw Pact countries taking part in the Intercosmos programme, including Vladimir Remek of Czechoslovakia. The longest expedition lasted 185 days. Salyut 6 was deorbited on 29 July 1982, almost five years after launch, and its operating pattern was carried forward on Mir and the International Space Station.