High Quality Content by WIKIPEDIA articles! Salyut 1 (DOS-1) (Russian: Салют-1; English translation: Salute 1) was the first space station of any kind, launched by the USSR on April 19, 1971. It was launched unmanned using a Proton-K rocket. Its first crew came later in Soyuz 10, but was unable to dock completely; its second crew launched in Soyuz 11 and remained on board for 23 days. A pressure-equalization valve in the Soyuz 11 reentry capsule opened prematurely when the crew was returning, killing all three. Following the accident, missions were temporarily suspended and the station was burned in the atmosphere purposely after a total of 6 months in orbit.