* February 9 – The Soyuz 17 crew ( Georgi Grechko, Aleksei Gubarev ) returns to Earth after 1 month aboard the Salyut 4 space station.

The heritage of the Salyut programme continued to live on in the first multi-module space station Mir with the Mir Core Module (" DOS-7 "), that accumulated 4, 592 days of occupancy, and in the International Space Station ( ISS ) with the Zvezda module (" DOS-8 "), that accumulated 4, 310 days of occupancy.

** Salyut 4

Soyuz 18 (, Union 18 ) was a 1975 Soviet manned mission to Salyut 4, the second and final crew to man the space station.

Klimuk and Sevastyanov were launched into space on 24 May 1975 and docked with Salyut 4 two days later.

After two successful missions, including a two-month stay on the Salyut 4 space station, he was pulled from active flight status in 1976.

After the successful 27 September 1973 launch, the craft was maneuvered to 326 x 344 km on the second day in space, which later proved to be the standard orbit for the Salyut 4 space station.

The next space station launched by the Soviet Union was the civilian station Salyut 4 ; the next military station was Salyut 5, which was the final Almaz space station.

These consisted of the unsuccessful DOS-2 in 1972, DOS-3 in 1974, and later the successful Salyut 4, Salyut 6, and Salyut 7.

On July 4, a little over a week after Salyut 3 was launched, the manned spacecraft Soyuz 14 docked with the station, having been launched the previous day.

The spacecraft which would have been used on the third mission to Salyut 3 was later used for the mission Soyuz 20 to Salyut 4 ( a civilian space station ).

NASA sources report that the parachute of Salyut 3's capsule opened at an altitude of 8. 4 km.

Three crews attempted to make stays aboard Salyut 4 ( Soyuz 17 and Soyuz 18 docked ; Soyuz 18a suffered a launch abort ).

Salyut 4 was deorbited February 2, 1977, and re-entered the Earth's atmosphere on February 3.

The DOS differed from the OPS modules in several aspects, with among others extra solar panels, front and ( in Salyut 6 and 7 ) rear docking ports for Soyuz spacecraft and TKS spacecraft, and finally more docking ports in DOS-7 and DOS-8 to attach further space station modules.

In the end it turned out that the Soviet N1 " Moon Shot " rocket never flew successfully, so OKB-1's decisions to abandon the ill fated Soviet maned lunar program, and to derive a DOS space station from existing Soyuz subsystems and an Almaz-OPS hull proved to be right: The actual time to the launch of the first DOS-based Salyut 1 space station from the get-go was an impressive 16 months – the world's first space station was launched by the Soviet Union, two years before Skylab or the first Almaz-OPS station flew.

* DOS ( Russian-language acronym, variously translated as Long-Duration / Durable / Permanent Orbital Station ), a designation for a series of Russian manned space stations, such as the Salyut program

Other civilian stations, called Durable Orbital Stations ( DOS ), were considered successors of Salyut 1.

* Kosmos 557-failed third DOS type space station in the Salyut program

Salyut 1 ( DOS-1 ) (; English translation: Salute 1 ) was the first space station of any kind, launched by the Soviet Union on April 19, 1971.

Salyut 3 (; ; also known as OPS-2 or Almaz 2 ) was a Soviet space station launched on June 25, 1974.

Salyut 6 (; lit.

Salyut 7 (; ) ( aka DOS-6 ) was a space station in low Earth orbit from April 1982 to February 1991.

The Salyut programme (,, Salute or Fireworks ) was the first space station program undertaken by the Soviet Union, which consisted of a series of four crewed scientific research space stations and two crewed military reconnaissance space stations over a period of 15 years from 1971 to 1986.

Salyut 2 ( OPS-1 ) ( meaning Salute 2 ) was a Soviet space station which was launched in 1973 as part of the Salyut programme.

Salyut 5 ( meaning Salute 5 ), also known as OPS-3, was a Soviet space station.

Salute 6 ), DOS-5, was a Soviet orbital space station, the eighth flown as part of the Salyut programme.

To perform these activities a specially designed URI multipurpose tool was used during a 3 hr, 30 min EVA outside the Salyut 7 space station.

The last military-use space station was Salyut 5, which was used by the Almaz program of the Soviet Union in 1976 and 1977.

The first space station was Salyut 1, which was launched by the Soviet Union on April 19, 1971.

This concept was expanded on Salyut 7, which " hard docked " with a TKS tug shortly before it was abandoned ; this served as a proof-of-concept for the use of modular space stations.

Mir was authorised in a decree made on 17 February 1976 to design an improved model of the Salyut DOS-17K space stations.

It was planned that the station's core module ( DOS-7 and the backup DOS-8 ) would be equipped with a total of four docking ports ; two at either end of the station as with the Salyut stations, and an additional two ports on either side of a docking sphere at the front of the station to enable further modules to expand the station's capabilities.

NPO Energia was responsible for the overall space station, with work subcontracted to KB Salyut, due to ongoing work on the Energia rocket and Salyut 7, Soyuz-T, and Progress spacecraft.

It was, on the one hand, designed to carry out long-term research into the problems of living in space and a variety of astronomical, biological and Earth-resources experiments, and on the other hand this civilian program was used as a cover for the highly secretive military Almaz stations, which flew as well under the Salyut designation.

) ( and at least a year earlier than Almaz ), the Salyut programme was incepted on February 15, 1970 – under the condition that the manned lunar program would not suffer.

Yet, as the launch of the first station in the program was prepared, it was realized that this would conflict with the call sign Zarya of the flight control centre ( TsUP ) in Korolyov – therefore the name of the space stations was changed to Salyut shortly before launch of Salyut 1.

Salyut 1's orbit was increased to prevent premature reentry, but further piloted flights were delayed while the Soyuz was redesigned to fix the new safety problem.

* 1971 – Launch of Salyut 1, the first space station.

In this period, the Soviets resumed EVAs, making four from the Salyut 6 and Salyut 7 space stations between December 20, 1977, and July 30, 1982.

She performed a space walk lasting 3 hours 35 minutes outside the Salyut 7 space station.

* 1984 – Salyut 7 cosmonaut Svetlana Savitskaya becomes the first woman to perform a space walk.

* 1980 – Soyuz 38 carries 2 cosmonauts ( including 1 Cuban ) to Salyut 6 space station.

The Soviet space program achieved many of the first milestones, including the first living being in orbit in 1957, the first human spaceflight ( Yuri Gagarin aboard Vostok 1 ) in 1961, the first spacewalk ( by Aleksei Leonov ) in 1965, the first automatic landing on another celestial body in 1966, and the launch of the first space station ( Salyut 1 ) in 1971.

* February 7 – The Soviet Union launches Soyuz 24 ( Viktor Gorbatko, Yuri Glazkov ) to dock with the Salyut 5 space station.

* July 25 – Salyut 7: Cosmonaut Svetlana Savitskaya becomes the first woman to perform a space walk.

** After a successful mission aboard Salyut 1, the world's first manned space station, the crew of the Soyuz 11 spacecraft are killed when their air supply leaks out through a faulty valve.

Other Soviet manned spacecraft include the Voskhod, Soyuz, unflown as manned Zond / L1, L3, TKS, and the Salyut and Mir manned space stations.

two space stations are in orbit ; the International Space Station, and China's Tiangong 1, ( which successfully launched on September 29, 2011, after failing in its prior August launch attempt ) Previous stations include the Almaz and Salyut series, Skylab and most recently Mir.

Since the ill-fated flight of Soyuz 11 to Salyut 1, all manned spaceflight duration records have been set aboard space stations.

The civilian stations Salyut 6 and Salyut 7 were built with two docking ports, which allowed a second crew to visit, bringing a new spacecraft with them ; the Soyuz ferry could spend 90 days in space, after which point it needed to be replaced by a fresh Soyuz spacecraft.

Finally, the Progress series of unmanned cargo ships for the Salyut and Mir space laboratories used the automatic navigation and docking mechanism ( but not the re-entry capsule ) of Soyuz.

* 1971 – Salyut 1, the first space station, launched by Kerim Kerimov

Following the success of the Salyut programme, Mir represented the next stage in the Soviet Union's space station programme.