Soyuz 7K-T

The Soyuz 7K-T was a Soviet crewed spacecraft built to ferry cosmonauts to Salyut space stations. It was a complete redesign of the earlier 7K-OKS ferry after the crew of Soyuz 11 died in 1971 when their cabin lost pressure on the way home. The new craft carried two cosmonauts instead of three, which made it possible for both to wear pressure suits during launch, docking and re-entry, and it used batteries in place of the solar panels of its predecessor so that a panel failing to deploy could no longer endanger a flight. Its first launch was the uncrewed test flight that the Soviet Union announced as Cosmos 496 on 26 June 1972, and its last flight went up in May 1981. It could stay in orbit for about 110 days, weighed roughly 6,800 kilograms at launch, and was replaced by the Soyuz T. Yuri Semenov led its design after the 1972 reorganisation of the design bureau.