Salyut 1

Salyut 1 (DOS-1) (Russian: Салют-1; English translation: Salute 1) was the first space station of any kind, launched by the Soviet Union on April 19, 1971. More stations followed in the Salyut programme, and heritage of that space station program is still in use on the ISS.

It was launched unmanned using a Proton-K rocket. The first crew launched later in the Soyuz 10 mission, but they ran into troubles while docking and were unable to enter the station; the Soyuz 10 mission was aborted and the crew returned safely to Earth. Its second crew launched in Soyuz 11 and remained on board for 23 days. This was the first time in the history of spaceflight that a space station had been manned, and a new record in time spent in space. This success was however overshadowed when the crew was killed during reentry, as a pressure-equalization valve in the Soyuz 11 reentry capsule had opened prematurely, causing the crew to suffocate. After this accident, missions were suspended while the Soyuz spacecraft was redesigned. The station was intentionally destroyed by de-orbiting it after six months in orbit, because it ran out of fuel before a redesigned Soyuz spacecraft could be launched to it.