Salyut 7

Salyut 7

Salyut 7 photographed following the undocking of Soyuz T-13, 25 September 1985
The insignia of the Salyut Program
Station statistics
COSPAR ID	1982-033A
SATCAT no.	13138
Crew	3
Launch	19 April 1982 19:45:00 UTC
Launch pad	LC-200/40, Baikonur Cosmodrome, Soviet Union
Reentry	7 February 1991[1]
Mass	19,824 kg
Length	16 m (minimum)[1]
Width	4.15 m (max)[1]
Pressurised volume	90 m³ (minimum)[1]
Perigee	219 km (118.25 nmi)
Apogee	278 km (150.1 nmi)
Orbital inclination	51.6 degrees
Orbital period	89.2 minutes
Days in orbit	3216 days
Days occupied	816 days
No. of orbits	51,917
Distance travelled	2,106,297,129 km (1,137,309,460 nmi)
Statistics as of de-orbit and reentry
Configuration
Salyut 7 with docked Kosmos 1686 TKS spacecraft

Salyut 7 (Russian: Салют-7; English: Salute 7) (a.k.a. DOS-6^[1]) was a space station in low Earth orbit from April 1982 to February 1991.^[1] It was first manned in May 1982 with two crew via Soyuz T-5, and last visited in June 1986, by Soyuz T-15.^[1] Various crew and modules were used over its lifetime, including 12 manned and 15 unmanned launches in total.^[1] Supporting spacecraft included the Soyuz T, Progress, and TKS spacecraft.^[1]

It was part of the Soviet Salyut programme, and launched on 19 April 1982 on a Proton rocket from Site 200/40 at the Baikonur Cosmodrome in the Soviet Union. Salyut 7 was part of the transition from "monolithic" to "modular" space stations, acting as a testbed for docking of additional modules and expanded station operations. It was the tenth space station of any kind launched. Salyut 7 was the last space station of the Salyut Program, which was replaced by Mir.

Description

Salyut 7 was the back-up vehicle for Salyut 6 and very similar in equipment and capabilities. With delays to the Mir programme it was decided to launch the back-up vehicle as Salyut 7. In orbit the station suffered technical failures though it benefited from the improved payload capacity of the visiting Progress and Soyuz craft and the experience of its crews who improvised many solutions (such as a fuel line rupture in September 1983 requiring EVAs by the Soyuz T-10 to repair). It was aloft for eight years and ten months (a record not broken until Mir), during which time it was visited by 10 crews constituting six main expeditions and four secondary flights (including French and Indian cosmonauts). The station also saw two flights of Svetlana Savitskaya making her the second woman in space since 1963 and the first to perform an EVA during which she conducted metal cutting and welding alongside her colleague Vladimir Dzhanibekov.^[2] Aside from the many experiments and observations made on Salyut 7, the station also tested the docking and use of large modules with an orbiting space station. The modules were called "Heavy Kosmos modules" though in reality were variants of the TKS spacecraft intended for the cancelled Almaz military space station. They helped engineers develop technology necessary to build Mir.

Equipment

Salyut 7 during assembly.

It had two docking ports, one on either end of the station, to allow docking with the Progress unmanned resupply craft, and a wider front docking port to allow safer docking with a Heavy Kosmos module. It carried three solar panels, two in lateral and one in dorsal longitudinal positions, but they now had the ability to mount secondary panels on their sides. Internally, the Salyut 7 carried electric stoves, a refrigerator, constant hot water and redesigned seats at the command console (more like bicycle seats). Two portholes were designed to allow ultraviolet light in, to help kill infections.^[1][3] The medical, biological and exercise sections were improved, to allow long stays in the station. The BST-1M telescope used in Salyut 6 was replaced by an X-ray detection system.^[3]

Crews and missions

Salyut 7 with docked spacecraft

Following up the use of Kosmos 1267 on Salyut 6, the Soviets launched Kosmos 1443 on 2 March 1983, from a Proton SL-13. It docked with the station on 10 March, and was used by the crew of Soyuz T-9. It jettisoned its recovery module on 23 August, and re-entered the atmosphere on 19 September. Kosmos 1686 was launched on 27 September 1985, docking with the station on 2 October. It did not carry a recovery vehicle, and remained connected to the station for use by the crew of Soyuz T-14. Ten Soyuz T crews operated in Salyut 7. Only two Interkosmos "guest cosmonauts" worked in Salyut 7. The first attempt to launch Soyuz T-10 was aborted on the launch pad when a fire broke out at the base of the vehicle. The payload was ejected, and the crew was recovered safely.

Technical and crew problems

The station suffered from two major problems, the first of which required extensive repair work to be performed on a number of EVAs.

Loss of power

The drifting station as seen from the approaching Soyuz T-13.

On 11 February 1985, contact with Salyut 7 was lost. The station began to drift, and all systems shut down. At this time the station was uninhabited, after the departure of Leonid Kizim, Vladimir Solovyov and Oleg Atkov, and before the next crew arrived. It was once again decided to attempt to repair the station, which was performed by Vladimir Dzhanibekov and Viktor Savinykh on the Soyuz T-13 mission during June 1985, in what was in the words of author David S. F. Portree "one of the most impressive feats of in-space repairs in history".^[1]

All Soviet and Russian space stations were equipped with automatic rendezvous and docking systems, from the first space station Salyut 1 using the Igla system, to the Russian Orbital Segment of the International Space Station using the Kurs system. Upon arrival, on 6 June 1985, the Soyuz crew found the station was not broadcasting radar or telemetry for rendezvous, and after arrival and external inspection of the tumbling station, the crew estimated proximity using handheld laser rangefinders.

Dzhanibekov piloted his ship to intercept the forward port of Salyut 7 and matched the station's rotation. After hard docking to the station and confirming the station's electrical system was dead, Dzhanibekov and Savinykh sampled the station atmosphere prior to opening the hatch. Attired in winter fur-lined clothing, they entered the station to conduct repairs. The fault was eventually found to be an electrical sensor that determined when the batteries needed charging.

Once the batteries were replaced, the station started charging them, and warmed up over the next few days.^[4] Within a week sufficient systems were brought back online to allow unmanned Progress cargo ships to dock with the station.^[1]

End of life

Salyut 7 was last inhabited in 1986 by the crew of Soyuz T-15, who ferried equipment from Salyut 7 to the new Mir space station. Between 19 and 22 August 1986, engines on Kosmos 1686 boosted Salyut 7 to a record-high mean orbital altitude of 475 km to forestall reentry until 1994. Retrieval at a future date by a Buran shuttle was also planned.^[5]

However, unexpectedly high solar activity in the late 1980s and early 1990s increased atmospheric drag on the station and sped its orbital decay. It finally underwent an uncontrolled reentry on 7 February 1991 over the town of Capitán Bermúdez in Argentina after it overshot its intended entry point, which would have placed its debris in uninhabited portions of the southern Pacific Ocean.^[6][7]

Expeditions and visiting spacecraft

Notation:

• EO (Russian: ЭО, Экспедиция Основная) or PE means Principal Expedition
• EP (Russian: ЭП, Экспедиция Посещения) or VE means Visiting Expedition

Specifications

Specifications of the baseline 1982 Salyut 7 module, from Mir Hardware Heritage (1995, NASA RP1357):^[1]

• Length – about 16 m
• Maximum diameter – 4.15 meters
• Habitable volume – 90 m³
• Weight at launch – 19,824 kg
• Launch vehicle – Proton rocket (three-stage)
• Orbital inclination – 51.6°
• Span across solar arrays – 17 m
• Area of solar arrays – 51 m²
• Number of solar arrays – 3
• Electricity available – 4.5 kW
• Resupply carriers – Soyuz-T, Progress, TKS spacecraft
• Docking System – Igla or manual approach
• Number of docking ports – 2
• Total manned missions – 12
• Total unmanned missions – 15
• Total long-duration missions – 6
• Number of main engines – 2
• Main engine thrust (each) – 300 kg

Visiting spacecraft and crews

(Launched crews. Spacecraft launch and landing dates listed.)

• Soyuz T-5 – 13 May – 27 August 1982
  • Anatoli Berezovoy
  • Valentin Lebedev
• Soyuz T-6 – 24 June – 2 July 1982 – Intercosmos Flight
  • Vladimir Dzhanibekov
  • Aleksandr Ivanchenkov
  • Jean-Loup Chrétien – France
• Soyuz T-7 – 19 August – 10 December 1982
  • Leonid Popov
  • Aleksandr Serebrov
  • Svetlana Savitskaya
• Soyuz T-8 – 20–22 April 1983 – Failed docking
  • Vladimir Titov
  • Gennady Strekalov
  • Aleksandr Serebrov
• Soyuz T-9 – 27 June – 23 November 1983
  • Vladimir Lyakhov
  • Alexander Alexandrov
• Soyuz T-10-1 – 26 September 1983 – Launch abort
  • Vladimir Titov
  • Gennady Strekalov
• Soyuz T-10 – 8 February – 11 April 1984
  • Leonid Kizim
  • Vladimir Solovyov
  • Oleg Atkov
• TKS 3 – 4 March – 14 August 1983 – Launched unmanned as Kosmos 1443.
• Soyuz T-11 – 3 April – 2 October 1984 – Intercosmos Flight
  • Yury Malyshev
  • Gennady Strekalov
  • Rakesh Sharma – India
• Soyuz T-12 – 17–29 July 1984
  • Vladimir Dzhanibekov
  • Svetlana Savitskaya
  • Igor Volk
• Soyuz T-13 – 6 June – 26 September 1985
  • Vladimir Dzhanibekov
  • Viktor Savinykh
• Soyuz T-14 – 17 September – 21 November 1985
  • Vladimir Vasyutin
  • Georgi Grechko
  • Alexander Volkov
• TKS 4 – September 1985 – 7 February 1991 – Launched unmanned as Kosmos 1686. Featured a high-resolution photo apparatus and optical sensor experiments (infrared telescope and Ozon spectrometer).
• Soyuz T-15 – 13 March – 16 July 1986 – Also visited Mir
  • Leonid Kizim
  • Vladimir Solovyov

In Popular Culture

The repair and reactivation of the station by Soyuz T-13 is the subject of the 2017 Russian historical drama Salyut 7.

See also

• List of spacewalks
• Skylab
• STS-61 (Hubble mirror fix-mission)

References

External links

• Nickolai Belakovski: The little-known Soviet mission to rescue a dead space station

External links

• http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1982-033A
• Soviet Space Stations as Analogs – NASA report (PDF format)