DOS-2 designation given to a

space station A space station is a spacecraft capable of supporting a human crew in orbit for an extended period of time, and is therefore a type of space habitat. It lacks major propulsion or landing systems. An orbital station or an orbital space station ...

, launched as part of the

Salyut program The ''Salyut'' programme (russian: Салют, , meaning "salute" or "fireworks") was the first space station programme, undertaken by the Soviet Union. It involved a series of four crewed scientific research space stations and two crewed m ...

me, which was lost in a launch failure on 29 July 1972, when the failure of the second stage of its

Proton-K The Proton-K, also designated Proton 8K82K after its GRAU index or SL-12 after its model number, 8K82K, was a Russian, previously Soviet, carrier rocket derived from the earlier Proton. It was built by Khrunichev, and launched from sites 81 an ...

launch vehicle prevented the station from achieving orbit. It instead fell into the Pacific Ocean. The station, which would have been given the designation Salyut 2 had it reached orbit, was structurally identical to

Salyut 1 Salyut 1 (DOS-1) (russian: Салют-1) was the world's first space station launched into low Earth orbit by the Soviet Union on April 19, 1971. The Salyut program followed this with five more successful launches of seven more stations. The fi ...

, as it had been assembled as a backup unit for that station. Four teams of cosmonauts were formed to crew the station, of which two would have flown: *

Alexei Leonov Alexei Arkhipovich Leonov. (30 May 1934 – 11 October 2019) was a Soviet and Russian cosmonaut, Air Force major general, writer, and artist. On 18 March 1965, he became the first person to conduct a spacewalk, exiting the capsule during th ...

and

Valeri Kubasov Valery Nikolaevich Kubasov (russian: Вале́рий Никола́евич Куба́сов; 7 January 1935 – 19 February 2014) was a Soviet/Russian cosmonaut who flew on two missions in the Soyuz programme as a flight engineer: Soyuz 6 and S ...

Vasily Lazarev Vasily Grigoryevich Lazarev (russian: Васи́лий Григо́рьевич Ла́зарев; 23 February 1928 31 December 1990) was a Soviet cosmonaut who flew on the Soyuz 12 spaceflight as well as the abortive Soyuz 18a launch on 5 April 1 ...

and Oleg Makarov *

Aleksei Gubarev Aleksei Aleksandrovich Gubarev (russian: Алексе́й Алекса́ндрович Гу́барев; 29 March 1931 – 21 February 2015) was a Soviet cosmonaut who flew on two space flights: Soyuz 17 and Soyuz 28. Biography Gubarev grad ...

and

Georgi Grechko Georgy Mikhaylovich Grechko (russian: Георгий Михайлович Гречко; 25 May 1931 – 8 April 2017) was a Soviet cosmonaut. He flew to space on three missions, each bound for rendezvous with a different Salyut space station.

Pyotr Klimuk Pyotr Ilyich Klimuk ( be, Пётр Ільіч Кліму́к; russian: Пётр Ильич Климу́к; born 10 July 1942) is a former Soviet cosmonaut and the first Belarusian to perform space travel. Klimuk made three flights into space. ...

and

Vitaly Sevastyanov Vitaly Ivanovich Sevastyanov (russian: Вита́лий Ива́нович Севастья́нов; 8 July 1935 – 5 April 2010) was a Soviet people, Soviet astronaut, cosmonaut and an engineer who flew on the Soyuz 9 and Soyuz 18 missions ...

Whilst Salyut 1 has been attempted to be visited by two three-man crews (

Soyuz 10 Soyuz 10 (russian: 'Союз 10', ''Union 10'') was launched on 22 April 1971 as the world's first mission to the world's first space station, the Soviet Salyut 1. The docking was not successful and the crew, Vladimir Shatalov, Aleksei Yel ...

and

Soyuz 11 Soyuz 11 (russian: link=no, Союз 11, lit=Union 11) was the only crewed mission to board the world's first space station, Salyut 1 (Soyuz 10 had soft-docked, but had not been able to enter due to latching problems). The crew, Georgy Dobrov ...

), following modifications to the

Soyuz 7KT-OK Soyuz 7K-OKS (also known as Soyuz 7KT-OK) is a version of the Soyuz spacecraft and was the first spacecraft designed for space station flights. Its only crewed flights were conducted in 1971, with Soyuz 10 and Soyuz 11. Design The two craf ...

spacecraft (resulting in the new model

Soyuz 7K-T The second generation of the Soyuz spacecraft, the ''Soyuz 7K-T'', comprised Soyuz 12 through Soyuz 40 (1973-1981). In the wake of the Soyuz 11 tragedy, the spacecraft was redesigned to accommodate two cosmonauts who would wear pressure ...

) following the deaths of the crew of Soyuz 11, the spacecraft could only carry two cosmonauts, thus DOS-2 would have been manned by two crews of two. Following the loss of the station, the crews were transferred to the DOS-3 programme.

References

Salyut program Space stations Satellite launch failures 1972 in the Soviet Union Spacecraft launched in 1972 Rocket launches in 1972 {{USSR-spacecraft-stub