The passive spacecraft in the second planned test of the Kontakt lunar rendezvous/docking system. One or two of the crew would have spacewalked to the Soyuz 11 Kontakt and returned in the other spacecraft.
Intended first space station mission; soft docked with Salyut 1. Soyuz 10 approached to 180 m from Salyut 1 automatically. It was hand docked after faillure of the automatic system, but hard docking could not be achieved because of the angle of approach. Post-flight analysis indicated that the cosmonauts had no instrument to proivde the angle and range rate data necessary for a successful manual docking. Soyuz 10 was connected to the station for 5 hours and 30 minutes. Despite the lack of hard dock, it is said that the crew were unable to enter the station due to a faulty hatch on their own spacecraft. When Shatalov tried to undock from the Salyut, the jammed hatch impeded the docking mechanism, preventing undocking. After several attempts he was unable to undock and land. During the landing, the Soyuz air supply became toxic, and Rukavishnikov (much like the case of Vance Brand during the Apollo ASTP return) was overcome and became unconscious. Recovered April 25, 1971 23:40 GMT. Landed 120 km NW Karaganda. Film and photos indicated that the docking system on the Salyut was not damaged, setting the stage for the Soyuz 11 mission.
First space station flight, two years before the American Skylab. Soyuz 11 was guided automatically to 100 m, then hand-docked to the Salyut 1 scientific station. Equipment aboard Salyut 1 included a telescope, spectrometer, electrophotometer, and television. The crew checked improved on-board spacecraft systems in different conditions of flight and conducted medico-biological research. The main instrument, a large solar telescope, was inoperative because its cover failed to jettison. A small fire and difficult working conditions led to decision to return crew before planned full duration of 30 days. Capsule recovered June 29, 1971 23:17 GMT, but when the hatch was opened it was found that the crew had perished due to a loss of cabin atmosphere. A pressure equalization valve was jerked loose at the jettison of the Soyuz Orbital Module. The valve was not supposed to open until an altitude of 4 km was reached. The three-man crew did not have space suits. The Soyuz was thereafter redesigned to accomodate only two crew, but in spacesuits. The actual Soyuz 11 Prime Crew was Leonov, Kubasov, and Kolodin. Dobrovolskiy, Volkov, Patsayev were their backups (and support crew to Soyuz 10). Kubasov was grounded by physicians few days before launch, and the back-up crew ended up going instead.