The Salyut programme (, , 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 military reconnaissance space stations over a period of 15 years, from 1971 to 1986. Two other Salyut launches failed. In one respect, Salyut had the space-race task of carrying 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, the USSR used this civilian programme as a cover for the highly secretive military Almaz stations, which flew under the Salyut designation. Salyut 1, the first station in the program, became the world's first crewed space station.
Salyut flights broke several spaceflight records, including several mission-duration records, and achieved the first orbital handover of a space station from one crew to another, and various spacewalk records. The ensuing Soyuz programme was vital for evolving space station technology from a basic, engineering development stage, from single docking port stations to complex, multi-ported, long-term orbital outposts with impressive scientific capabilities, whose technological legacy continues .
History of Salyut space stations
The programme was composed of civilian stations and military stations:
- The Almaz-OPS space station cores were designed in October 1964 by Vladimir Chelomey's NPO Mashinostroyeniya (OKB-52) organization as military space stations, long before the Salyut programme started. For Salyut, small modifications had to be made to the docking port of the OPS to accommodate Soyuz spacecraft in addition to TKS spacecraft.
- The civilian DOS space station cores were designed by Sergei Korolev's OKB-1 organisation. Korolev and Chelomey had been in fierce competition in the Soviet space industry during the time of the Soviet crewed lunar programme, but OKB-52's Almaz-OPS hull design was combined with subsystems derived from OKB-1's Soyuz. This was done beginning with conceptual work in August 1969. The DOS differed from the OPS modules in several aspects, including 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.
It was realized that the later civilian DOS stations could not only offer a cover story for the military Almaz programme, but could also be finished within one year and at least a year earlier than Almaz. The Salyut programme begun on 15 February 1970 on the condition that the crewed lunar programme would not suffer. Another explanation given is that the name might have offended the Chinese, who purportedly were preparing a new rocket for launch, which they had already named Shuguang or "Dawn". The Salyut programme was managed by Kerim Kerimov, chairman of the state commission for Soyuz missions.
A total of nine space stations were launched in the Salyut programme, with six successfully hosting crews and setting some records along the way. However, it was the stations Salyut 6 and Salyut 7 that became the workhorses of the programme. Out of the total of 1,697 days of occupancy that all Salyut crews achieved, Salyut 6 and 7 accounted for 1,499. While Skylab already featured a second docking port, these two Salyut stations became the first that actually utilised two docking ports: this made it possible for two Soyuz spacecraft to dock at the same time for crew exchange of the station and for Progress spacecraft to resupply the station, allowing for the first time a continuous ("permanent") occupation of space stations.
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. Furthermore, the Functional Cargo Block space station modules were derived from the Almaz programme, with the Zarya ISS module being still in operation together with Zvezda.
Salyut 4 (DOS-4)
thumb|[[Salyut 4 diagram]]
Salyut 5 (OPS-3, military)
Second generation – long-duration inhabitation of space
thumb|Mockup of Soyuz and Progress spacecraft docked to Salyut 6, Moscow Polytechnical Museum
In 1977, another marked step forward was made with the second generation of Salyut stations. The aim was to continuously occupy a space station with long-duration expeditions, for the first time in spaceflight.
Although Salyut 6 and Salyut 7 resembled the previous Salyut stations in overall design, several revolutionary changes were made to the stations and programme for the aim of continuous occupation. The new stations featured a longer design life and a second docking port at the aft of the stations – crew exchanges and station "handovers" were now made possible by docking two crewed Soyuz spacecraft at the same time. Furthermore, the uncrewed Progress resupply craft was created based on the crewed Soyuz, to resupply the crew and station with air, air regenerators, water, food, clothing, bedding, mail, propellants, pressurant, and other supplies. While the Progress docked to the station's second docking port, the crew's Soyuz spacecraft could remain docked to the station's first port. The Progress spacecraft even delivered hardware for updating onboard experiments and permitting repairs to the station, extending its life.
Salyut 6 (DOS-5)
thumb|DOS-5 ([[Salyut 6) space station with two docked spacecraft]]
Salyut 7 (DOS-6)
thumb|A full-scale model of a [[Salyut 7 space station and two docked spacecraft. On the left a Soyuz can be seen docked to the fore port, and on the right a Progress is docked at the aft port. The display is in front of one of the pavilions of the Exhibition of Soviet National Economic Achievement.]]
Salyut's heritage – modular space stations
After the second generation, plans for the next generation of Salyut stations called for the cores DOS-7 and DOS-8 to allow, for the first time in spaceflight, the addition of several modules to a station core and to create a modular space station. For this, the DOS modules were to be equipped with a total of four docking ports: one docking port at the aft of the station as in the second generation Salyuts, and the replacement of the front docking port with a "docking sphere" containing three docking ports — front, port, and starboard.
While the station cores DOS-7 and DOS-8 were built and flown, they never received the Salyut designation. Instead, DOS-7 evolved into the Mir Core Module for the Mir space station that followed the Salyut programme, and DOS-8 was used as the Zvezda Service Module for the International Space Station (ISS) which followed Mir.
The heritage from the Almaz programme is present even today. While the last space station from the Almaz programme was flown as Salyut 5 in 1976, the development of the Almaz TKS spacecraft evolved into the Functional Cargo Block, which formed the basis for several Mir modules, the experimental Polyus orbital weapons platform and the Zarya module of the ISS.
Zvezda ISS Service Module (DOS-8)
thumb|DOS-8 ([[Zvezda (ISS module)|Zvezda ISS module)]]
DOS-8 evolved into the Mir-2 project, intended to replace Mir. Finally, it became the International Space Station (ISS) Zvezda Service Module and formed the core of the early ISS together with the Zarya module (which was derived from Almaz Functional Cargo Block designs).
Data table
The first generation of Salyut stations received few craft for rendezvous and docking. By contrast the programme's second generation stations, Salyut 6 and Salyut 7, received multiple crewed and uncrewed craft for rendezvous, docking attempts (whether successful or not), human habitation, crew transfer, and supply. The table counts craft which achieved rendezvous with their targets as visiting craft, regardless of whether they docked successfully.
{| class="wikitable" <!--very difficult to read otherwise -- border="0" cellpadding="8" cellspacing="0" -->
|-
! Space<br/>station
! Core<br/>module
! Launched
! Reentered
! Days in<br/>orbit
! Days<br/>occupied
! All crew<br/>and visitors<br/>(total)
! Visiting<br/>crewed<br/>spacecraft
! Visiting<br/>uncrewed<br/>spacecraft
! style="text-align:center;"|Mass<br/>kg
|-
| style="text-align:center;"| Salyut 1
|| DOS-1
||19 April 1971<br/>01:40:00 UTC
||11 October 1971<br/> <!--00:00:00 UTC-->
|align="right"|
|align="right"|23
|align="right"|3
|align="right"|2
|align="right"|-
|align="right"|18,500
|-
| style="text-align:center;"| -
|| DOS-2
||29 July 1972
||29 July 1972
|align="right"|-
|align="right"|-
|align="right"|-
|align="right"|-
|align="right"|-
|align="right"|18,500
|-
| style="text-align:center;"| Salyut 2
|| OPS-1 (military)
||4 April 1973<br/>09:00:00 UTC
||28 May 1973<br/> <!--00:00:00 UTC-->
|align="right"|
|align="right"|-
|align="right"|-
|align="right"|-
|align="right"|-
|align="right"|18,500
|-
| style="text-align:center;"| -<br/>(Kosmos 557)
|| DOS-3
||11 May 1973<br/>00:20:00 UTC
||22 May 1973<br/> <!--00:00:00 UTC-->
|align="right"|
|align="right"|-
|align="right"|-
|align="right"|-
|align="right"|-
|align="right"|19,400
|-
| style="text-align:center;"| Salyut 3
|| OPS-2 (military)
||25 June 1974<br/>22:38:00 UTC
||24 January 1975<br/> <!--00:00:00 UTC-->
|align="right"|
|align="right"|15
|align="right"|2
|align="right"|2
|align="right"|-
|align="right"|18,500
|-
| style="text-align:center;"| Salyut 4
|| DOS-4
||26 December 1974<br/>04:15:00 UTC
||3 February 1977<br/> <!--00:00:00 UTC-->
|align="right"|
|align="right"|92
|align="right"|4
|align="right"|2
|align="right"|1
|align="right"|18,500
|-
| style="text-align:center;"| Salyut 5
|| OPS-3 (military)
||22 June 1976<br/>18:04:00 UTC
||8 August 1977<br/> <!--00:00:00 UTC-->
|align="right"|
|align="right"|67
|align="right"|4
|align="right"|3
|align="right"|-
|align="right"|19,000
|-
| style="text-align:center;"| Salyut 6
|| DOS-5
||29 September 1977<br/>06:50:00 UTC
||29 July 1982<br/> <!--00:00:00 UTC-->
|align="right"|
|align="right"|683
|align="right"|33
|align="right"|18
|align="right"|15
|align="right"|19,824
|-
| style="text-align:center;"| Salyut 7
|| DOS-6
||19 April 1982<br/>19:45:00 UTC
||7 February 1991<br/> <!--00:00:00 UTC-->
|align="right"|
|align="right"|816
|align="right"|26
|align="right"|11
|align="right"|15
|align="right"|18,900
|-
|colspan="10"| For comparison, the DOS-7 and DOS-8 modules that were derived from the Salyut programme:
|-
| style="text-align:center;"| Mir
|| DOS-7<br/>Mir Core Module
||19 February 1986
||23 March 2001<br/><!--05:59 UTC-->
|align="right"|
|align="right"|4,592
|align="right"|104
|align="right"|39
|align="right"|64
|align="right"|20,400
|-
| style="text-align:center;"| ISS
|| DOS-8<br/>Zvezda<br/>ISS Service Module
||12 July 2000<br/>||Still in orbit
|align="right"|8,723
|align="right"|7,500
|align="right"|215<!-- Update after each expedition -->
|align="right"|85<br/><!-- Update after each expedition -->
|align="right"|65<br/><!-- Update after each expedition -->
|align="right"|19,051
|}
See also
- List of human spaceflights to Salyut space stations
- List of Salyut expeditions
- List of Salyut visitors
- List of Salyut spacewalks
- List of uncrewed spaceflights to Salyut space stations
References
External links
- "Diaries of the Salyut missions" at Zarya.info
- "Skylab-Salyut Space Laboratory (1972)" at Wired.com