The Soyuz-T (, Union-T) spacecraft was the third generation Soyuz spacecraft, in service for seven years from 1979 to 1986. The T stood for transport (транспортный, Transportny). The revised spacecraft incorporated lessons learned from the Apollo Soyuz Test Project, Soyuz 7K-TM and Military Soyuz. The Soyuz-T was a major upgrade over previous Soyuz spacecraft, sporting solid-state electronics for the first time and a much more advanced onboard computer to help overcome the chronic docking problems that affected cosmonauts during space station missions. In addition, solar panels returned, allowing the Soyuz-T to fly up to 11 days independently as well as a redesigned propulsion system, the KTDU-426. Finally, it could carry three cosmonauts with pressure suits.

Missions

Between 1979 and 1986, a total of 18 Soyuz T spacecraft were launched into LEO, 13 of which carried cosmonauts to and from the space stations Salyut 6, Salyut 7, and Mir.