Salyut 7 Explained

Station:Salyut 7
Station Image:Salyut7.jpg
Station Image Size:300px
Station Image Caption:Salyut 7 photographed by Soyuz T-13 crew before docking, 25 September 1985
Insignia:Salyut_program_insignia.svg
Insignia Caption:The insignia of the Salyut Program
Reentry:7 February 1991
Length:16 m (minimum)
Width:4.15 m (max)
Volume:90 m³ (minimum)
Perigee:219 km (118.25 nmi)
Apogee:278 km (150.1 nmi)
Period:89.21minutes
In Orbit:3215 days
Occupied:816 days
Orbits:51,917
Distance:2,106,297,129 km
(1,137,309,460 nmi)
As Of:de-orbit and reentry
Configuration Image:Salyut 7 and Cosmos 1686 drawing.png
Configuration Caption:Salyut 7 with docked Kosmos 1686 TKS spacecraft

Salyut 7 (Russian: Салют-7; English: '''Salute 7''') (a.k.a. DOS-6, short for Durable Orbital Station) was a space station in low Earth orbit from April 1982 to February 1991. It was first crewed in May 1982 with two crew via Soyuz T-5, and last visited in June 1986, by Soyuz T-15. Various crew and modules were used over its lifetime, including 12 crewed and 15 uncrewed launches in total. Supporting spacecraft included the Soyuz T, Progress, and TKS spacecraft.

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 eighth space station of any kind launched. Salyut 7 was the last of both the second generation of DOS-series space stations and of the monolithic Salyut Program overall, to be replaced by Mir, the modular, expandable, third generation.

Description

Salyut 7 was the backup vehicle for Salyut 6 and was 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 crew 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 Valentina Tereshkova first flew in June 1963 and the first woman to perform an EVA during which she conducted metal cutting and welding alongside her colleague Vladimir Dzhanibekov. 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 intended for the cancelled Almaz military space station. They helped engineers develop the technology necessary to build Mir.

Equipment

It had two docking ports, one on either end of the station, to allow docking with the Progress uncrewed 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. 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.

To support experiments in cultivating plants in space, several different plant life support systems were installed: Oasis 1A, Vazon, Svetoblok, Magnetogravistat, Biogravistat and Fiton(Phyton)-3. It was in Fiton-3 that Arabidopsis became the first plants to flower and produce seeds in the zero gravity of space.

Salyut 7 was the most advanced and comfortable space station of the Salyut series. A set of modifications to the interior made it more liveable. There were approximately 20 windows with shades on the Salyut 7. To protect the inside of the windows, they were covered with removable glass panels. The colour scheme was improved and a refrigerator was installed. The ceiling on the Salyut 7 was white; the left wall was apple green and the right one beige, a signature design by interior design architect, Galina Balashova, who carried on the concept through Soyuz to Mir and Buran, in an effort to replace 'survive' with 'comfort', working with seasoned cosmonauts to make living conditions better and 'closer to home' Externally, in a departure from previous first generation stations, the large diameter operations section which housed the large scientific apparatus, was colored in a distinctive brown-red and white stripe pattern. This was done to differentiate between it and the outwardly similar Salyut 6 that, for several months of its life, was in orbit at the same time.

Crews and missions

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.

Salyut 7 was the first manned space vehicle to launch a satellite, when it fired the small experimental Iskra 2 satellite out of its waste airlock. This was performed mainly to deprive the US Space Shuttle of becoming the first manned spacecraft to launch a satellite.

Resident crews

Salyut 7 had six resident crews.

There were also four visiting missions, crews which came to bring supplies and make shorter duration visits with the resident crews.

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.

Leaks

On 9 September 1983, during the stay of Vladimir Lyakhov and Alexander Alexandrov, while reorienting the station to perform a radiowave transmission experiment, Lyakhov noticed the pressure of one fuel tank was almost zero. Following this, Alexandrov spotted a fuel leak when looking through the aft porthole. Ground control decided to try to repair the damaged pipes, in what was the most complex repair attempted during EVA at the time. This was to be attempted by the next crew, the current one lacking the necessary training and tools. The damage was eventually repaired by Leonid Kizim and Vladimir Solovyov, who needed four EVAs to fix two leaks. A special tool to fix the third leak was delivered by Soyuz T-12, and the leak was subsequently fixed.

Loss of power

On 11 February 1985, contact with Salyut 7 was lost. The station began to drift, making unpredictable movements in orbit, 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. The work 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". This operation forms the basis of the 2017 Russian film Salyut 7.

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. Within a week sufficient systems were brought back online to allow uncrewed Progress cargo ships to dock with the station.

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.

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.

Expeditions and visiting spacecraft

Notation:

Expeditions

ExpeditionCrewLaunch dateFlight upLanding dateFlight
down
Duration
(days)
Salyut 7 – EO-1 Anatoli Berezovoy,
Valentin Lebedev
13 May 1982
09:58:05 UTC
Soyuz T-510 December 1982
19:02:36 UTC
Soyuz T-7211.38
Salyut 7 – EP-1 Vladimir Dzhanibekov,
Aleksandr Ivanchenkov,
Jean-Loup Chrétien – France
24 June 1982
16:29:48 UTC
Soyuz T-62 July 1982
14:20:40 UTC
Soyuz T-67.91
Salyut 7 – EP-2 Leonid Popov,
Aleksandr Serebrov,
Svetlana Savitskaya
19 August 1982
17:11:52 UTC
Soyuz T-727 August 1982
15:04:16 UTC
Soyuz T-57.91
Salyut 7 – EO-2 Vladimir Lyakhov,
Aleksandr Pavlovich Aleksandrov
27 June 1983
09:12:00 UTC
Soyuz T-923 November 1983
19:58:00 UTC
Soyuz T-9149.45
Salyut 7 – EO-3 Leonid Kizim,
Vladimir Solovyov,
Oleg Atkov
8 February 1984
12:07:26 UTC
Soyuz T-102 October 1984
10:57:00 UTC
Soyuz T-11236.95
Salyut 7 – EP-3 Yury Malyshev,
Gennady Strekalov,
Rakesh Sharma – India
3 April 1984
13:08:00 UTC
Soyuz T-1111 April 1984
10:48:48 UTC
Soyuz T-107.90
Salyut 7 – EP-4 Vladimir Dzhanibekov,
Svetlana Savitskaya,
Igor Volk
17 July 1984
17:40:54 UTC
Soyuz T-1229 July 1984
12:55:30 UTC
Soyuz T-1211.80
Salyut 7 – EO-4-1a Viktor Savinykh6 June 1985
06:39:52 UTC
Soyuz T-1321 November 1985
10:31:00 UTC
Soyuz T-14168.16
Salyut 7 – EO-4-1b Vladimir Dzhanibekov6 June 1985
06:39:52 UTC
Soyuz T-1326 September 1985
09:51:58 UTC
Soyuz T-13112.13
Salyut 7 – EP-5 Georgi Grechko17 September 1985
12:38:52 UTC
Soyuz T-1426 September 1985
09:51:58 UTC
Soyuz T-138.88
Salyut 7 – EO-4-2 Vladimir Vasyutin,
Alexander Volkov
17 September 1985
12:38:52 UTC
Soyuz T-1421 November 1985
10:31:00 UTC
Soyuz T-1464.91
Salyut 7 – EO-5 Leonid Kizim,
Vladimir Solovyov
13 March 1986
12:33:09 UTC
Soyuz T-1516 July 1986
12:34:05 UTC
Soyuz T-15125.00
50 on S7

Spacewalks

SpacecraftSpacewalker Start – UTCEnd – UTCDurationComments
Salyut 7 – PE-1 – EVA 1Lebedev, Berezevoi30 July 1982
02:39
30 July 1982
05:12
2 h, 33 minRetrieve experiments
Salyut 7 – PE-2 – EVA 1Lyakhov, Alexandrov1 November 1983
04:47
1 November 1983
07:36
2 h, 50 minAdd solar array
Salyut 7 – PE-2 – EVA 2Lyakhov, Alexandrov3 November 1983
03:47
3 November 1983
06:42
2 h, 55 minAdd solar array
Salyut 7 – PE-3 – EVA 1Kizim, Solovyov23 April 1984
04:31
23 April 1984
08:46
4 h, 20 minODU repair
Salyut 7 – PE-3 – EVA 2Kizim, Solovyov26 April 1984
02:40
26 April 1984
07:40
4 h, 56 minRepair ODU
Salyut 7 – PE-3 – EVA 3Kizim, Solovyov29 April 1984
01:35
29 April 1984
04:20
2 h, 45 minRepair ODU
Salyut 7 – PE-3 – EVA 4Kizim, Solovyov3 May 1984
23:15
4 May 1984
02:00
2 h, 45 minRepair ODU
Salyut 7 – PE-3 – EVA 5Kizim, Solovyov18 May 1984
17:52
18 May 1984
20:57
3 h, 05 minAdd solar array
Salyut 7 – VE-4 – EVA 1Savitskaya, Dzhanibekov25 July 1984
14:55
25 July 1984
18:29
3 h, 35 minFirst woman EVA
Salyut 7 – PE-3 – EVA 6Kizim, Solovyov8 August 1984
08:46
8 August 1984
13:46
5 h, 00 minComplete ODU repair
Salyut 7 – PE-4 – EVA 1Dzhanibekov, Savinykh2 August 1985
07:15
2 August 1985
12:15
5 h, 00 minAugment solar arrays
Salyut 7 – PE-6 – EVA 1Kizim, Solovyov28 May 1986
05:43
28 May 1986
09:33
3 h, 50 minTest truss, retrieve samples
Salyut 7 – PE-6 – EVA 2Kizim, Solovyov31 May 1986
04:57
31 May 1986
09:57
5 h, 00 minTest truss

Docking operations

On three occasions, a visiting Soyuz craft was transferred from the station's aft port to its forward port. This was done to accommodate upcoming Progress shuttles, which could only refuel the station using connections available at the aft port. Typically, the resident crew would first dock at the forward port, leaving the aft port available for Progress craft and visiting Soyuz support crews. When a support crew docked at the aft port and left in the older, forward Soyuz, the resident crew would move the new vehicle forward by boarding it, undocking, and translating some 100–200 meters away from Salyut 7. Then, ground control would command the station itself to rotate 180 degrees, and the Soyuz would close and re-dock at the forward port. Soyuz T-7, T-9 and T-11 performed the operation, piloted by resident crews.

Specifications

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

Visiting spacecraft and crews

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

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. These events also served as a plot base for the Polish novel Połowa nieba (pol. Half the sky), by Bartek Biedrzycki (first published 2018), collected in Zimne światło gwiazd in 2020.

See also