Salyut 6

Salyut 6 (Russian: Салют-6; lit. Salute 6), DOS-5, was a Soviet orbital space station, the eighth flown as part of the Salyut programme. Launched on 29 September 1977 by a Proton rocket, the station was the first of the "second-generation" type of space station. Salyut 6 possessed several revolutionary advances over the earlier Soviet space stations, which it nevertheless resembled in overall design. These included the addition of a second docking port, a new main propulsion system and the station's primary scientific instrument, the BST-1M multispectral telescope. The addition of the second docking port made crew handovers and station resupply by unmanned Progress freighters possible for the first time. The early Salyut stations had no means of resupply or removing accumulated garbage (aside from the limited amount that cosmonauts could carry in their Soyuz spacecraft), nor could the propulsion system be refueled once it exhausted its propellant supply. Consequently, once the consumables launched with the station were used up, its mission had to be concluded, and as a result, crewed missions had a maximal duration of three months. Progress spacecraft could now bring fresh supplies and propellant and also be used to dispose of waste, which was then destroyed once the spacecraft was deorbited.

Salyut 6

Salyut 6 with docked Soyuz and Progress.
Salyut programme logo.
Station statistics
COSPAR ID	1977-097A
SATCAT no.	10382
Call sign	Salyut 6
Crew	3
Launch	29 September 1977 06:50:00 UTC
Launch pad	Baikonur Cosmodrome, LC-81/24
Reentry	29 July 1982
Mass	19824 kg
Length	15.8 m
Diameter	4.15 m
Pressurised volume	90 m³
Periapsis altitude	219 km
Apoapsis altitude	275 km
Orbital inclination	51.66°
Orbital period	89.1 minutes
Orbits per day	16.16
Days in orbit	1764 days
Days occupied	683 days
No. of orbits	28,024
Distance travelled	~1,136,861,930 km
Statistics as of deorbit on 29 July 1982 References: [1][2]
Configuration
Basic orbital configuration of Salyut 6

Five crew residencies took place over the station's lifespan, from 1977-1981, including cosmonauts from Warsaw Pact countries as part of the Intercosmos programme. These crews were responsible for carrying out the primary missions of Salyut 6, including astronomy, Earth-resources observations and the study of the effect of spaceflight on the human body. Following the completion of these missions and the launch of its successor, Salyut 7, Salyut 6 was deorbited on 29 July 1982, almost five years after its launch.[1][3]

Description

Salyut 6, launched on a Proton 8K82K rocket on 29 September 1977,[4] marked the switch from engineering development stations to routine operations, and united the most effective elements from each of the previous stations. Its navigation system, made up of the Delta semi-automatic computer to depict the station's orbit and the Kaskad system to control its orientation, was based on that used on Salyut 4, as was its power system, which consisted of a trio of steerable solar panels, together producing a peak of 4 kilowatts of power over 51 m². The station's thermal regulation systems, which made use of a sophisticated arrangement of insulation and radiators, was also derived from that used on Salyut 4. In addition, Salyut 6 made use of environmental systems first used on Salyut 3, and controlled its orientation using gyrodynes first tested on that station.[1]

Salyut 6 with Progress (P) and Soyuz (F) spacecraft

The most important feature on Salyut 6, however, was the addition of a second docking port on the aft end of the station, which allowed two spacecraft to be docked at once. This, in turn, allowed resident crews to receive shorter, "visiting" expeditions whilst they remained on board, and for crew handovers to take place. In addition, it allowed Soyuz spacecraft that had exceeded their operating lifespan to be returned to Earth and replaced by fresh ones (the Soyuz 7K used from 1972 to 1981 had a maximal operating lifespan of three months). Such handovers, with one expedition vacating the station only after the next had arrived, permitted the long sought-after aim of continuous occupation to move a step closer. The very first long-duration crew to visit the station broke a long-standing endurance record set on board the American Skylab station, staying 96 days in orbit, whilst the longest expedition lasted 185 days. Some of the visiting expeditions were flown as part of the Intercosmos programme, with non-Soviet cosmonauts visiting the station. Vladimír Remek of Czechoslovakia, the first space traveller not from the US or USSR, visited Salyut 6 in 1978, and the station hosted cosmonauts from Hungary, Poland, Romania, Cuba, Mongolia, Vietnam, and East Germany.[1]

The rearward of the two ports was fitted with plumbing to allow the station to be refueled by unmanned Progress spacecraft. These freighters, which brought supplies and extra equipment to keep the station replenished, helped ensure that the crew were always able to carry out useful scientific work aboard the station. In all, twelve Progress flights delivered over 20 tonnes of equipment, supplies and fuel.[1]

The addition of the extra docking port caused the adoption of the Almaz-derived twin-chamber propulsion system first used on Salyut 3 and 5, with the two engine nozzles – each producing 2.9 kilonewtons of thrust – mounted peripherally on either side of the aft port. Salyut 6 introduced a Unified Propulsion System, with both the engines and the station's control thrusters running on unsymmetrical dimethylhydrazine and nitrogen tetroxide, drawn from a common set of pressurized tanks, allowing the refueling capabilities of the visiting Progress tankers to be exploited to the maximal effect. The entire engine and fuel storage assembly was contained within an unpressurized bay at the rear of the station, which had the same diameter as the main pressurized compartment. However, the replacement of the Soyuz engine used on previous stations with the bay meant that the station kept an overall length similar to its predecessors.[1] The main engines could not be fired if the rear docking port was in use, hence any orbital maneuvers during this time had to be performed by the visiting spacecraft.

Salyut 6's propulsion system experienced a serious malfunction during the second crew residency in 1978 and was not usable again for the remainder of the station's lifespan. As a consequence, it was limited to firing its attitude-control thrusters, and visiting spacecraft had to perform orbital adjustments. After each crew residency ended, it was necessary for Progress and TKS spacecraft to boost the station into a high orbit, so it wouldn't decay until the next residency began.

To enable spacewalks, Salyut 6 was equipped with an inward-opening EVA hatch on the side of the forward transfer compartment, which could be used as an airlock in a similar way to the system used on Salyut 4. This compartment contained two new semi-rigid spacesuits, which allowed much greater flexibility than earlier suits and could be donned within five minutes in case of an emergency. Finally, the station offered considerable improvements in living conditions over previous outposts, with machinery being soundproofed, the crews being provided with designated "cots" for sleeping and the equipping of the station with a shower and extensive gymnasium.[1]

Instruments

The primary instrument carried aboard the station was the BST-1M multispectral telescope, which could carry out astronomical observations in the infrared, ultraviolet and submillimetre spectra using a 1.5 metre-diameter mirror, which was operated in cryogenic conditions at around −269 °C (4 K). The telescope could be operated only when Salyut 6 was on the night side of the Earth and had its cover closed for the rest of the time.[1]

The second major instrument was the MKF-6M multispectral camera, which carried out Earth-resources observations. An improved form of a camera first tested on Soyuz 22, the camera captured an area of 165 × 220 kilometres with each image, down to a resolution of 20 metres. Each image was captured simultaneously in six bands in 1200-frame cassettes, which required regular replacement due to the fogging effects of radiation. Salyut 6 also featured a KATE-140 stereoscopic topographic mapping camera with a focal length of 140 millimetres, which captured images of 450 × 450 kilometres with a resolution of 50 metres in the visible and infrared spectra, which could be operated either remotely or by the resident crews. The photographic capabilities of the station were, therefore, extensive, and the Soviet Ministry of Agriculture had planted a number of specifically selected crops at test sites to examine the capabilities of the cameras.[1]

To further expand its scientific capabilities, Salyut 6 was equipped with 20 portholes for observations, two scientific airlocks to expose equipment to space or eject rubbish, and various pieces of apparatus to carry out biological experiments. Later on during the flight, a Progress spacecraft delivered an external telescope, the KRT-10 radio observatory, which incorporated a directional antenna and five radiometers. The antenna was deployed on the rear docking assembly, with the controller remaining inside the station, and was used for both astronomical and meteorological observations.[1]

Support craft

The original Progress variant, which was first used to resupply Salyut 6 in 1978.

Salyut 6 was primarily supported by the manned Soyuz spacecraft, which carried out crew rotations and would also have been used in the event of an emergency evacuation. The ferries docked automatically to the station, making use of the new Igla automatic docking system, and were used by departing crews to return to Earth at the end of their flight.[5]

The station was the first to be able to be resupplied by the newly developed unmanned Progress freighters, although they could only dock at the rear port, as the front port lacked the plumbing used to refuel the propulsion system. The freighters docked automatically to the station via the Igla, and were then opened and emptied by the cosmonauts on board, whilst transfer of fuel to the station took place automatically under supervision from the ground.[1][5]

In addition to the Soyuz and Progress spacecraft, after the final crew had left, Salyut 6 was visited by an experimental transport logistics spacecraft called Kosmos 1267 in 1982. The transport logistics spacecraft, known as the TKS, was originally designed for the Almaz programme, and proved that large modules could dock automatically with space stations, a major step toward the construction of multimodular stations such as Mir and the International Space Station.[6][7]

Resident crews

The station received 16 cosmonaut crews, including six long-duration crews, with the longest expedition lasting 185 days. Resident crew missions were identified with an EO prefix, whilst short-duration missions were identified with EP.

1. On 10 December 1977 the first resident crew, Yuri Romanenko and Georgy Grechko, arrived on Soyuz 26 and remained aboard Salyut 6 for 96 days.
2. On 15 June 1978, Vladimir Kovalyonok and Aleksandr Ivanchenkov (Soyuz 29) arrived and remained on board for 140 days.
3. Vladimir Lyakhov and Valery Ryumin (Soyuz 32) arrived on 25 February 1979 and stayed 175 days.
4. On 9 April 1980 Leonid Popov and Valery Ryumin (Soyuz 35) arrived for the longest stay on Salyut 6, 185 days. While aboard, on 19 July 1980, they sent their greetings to the Olympians and wished them happy starts in the live communication between the station and the Central Lenin Stadium, where the opening ceremony of the 1980 Summer Olympics was held. They appeared on the stadium's scoreboard and their voices were translated via loud speakers.
5. A repair mission, consisting of Leonid Kizim, Oleg Makarov, and Gennady Strekalov (Soyuz T-3) worked on the space station for 12 days starting on 27 November 1980.
6. On 12 March 1981 the last resident crew, Vladimir Kovalyonok and Viktor Savinykh, arrived and stayed for 75 days.

Station operations

Docking operations

Spacecraft	Docking day	Docking time	Port	Undocking day	Undocking time	Duration (days)
Soyuz 25	10 October 1977	07:09	front	11 October 1977	~08:00	1.03
Soyuz 26	11 December 1977	06:02	rear	16 January 1978	14:22	36.35
Soyuz 27	11 January 1978	17:06	front	16 March 1978	11:00	63.75
Progress 1	22 January 1978	13:12	rear	7 February 1978	08:55	15.82
Soyuz 28	3 March 1978	20:10	rear	10 March 1978	13:25	6.72
Soyuz 29	17 June 1978	00:58	front	3 September 1978	11:23	78.43
Soyuz 30	29 June 1978	20:08	rear	5 July 1978	13:15	6.71
Progress 2	9 July 1978	15:59	rear	2 August 1978	07:57	23.66
Progress 3	10 August 1978	03:00	rear	21 August 1978	–	~11
Soyuz 31	27 August 1978	19:37	rear	7 September 1978	13:53	10.76
Soyuz 31	7 September 1978	14:21	front	2 November 1978	10:46	55.85
Progress 4	6 October 1978	04:00	rear	24 October 1978	16:07	18.50
Soyuz 32	26 February 1979	08:30	front	13 June 1979	12:51	107.18
Progress 5	14 March 1979	10:20	rear	3 April 1979	19:10	20.37
Progress 6	15 May 1979	09:19	rear	8 June 1979	11:00	24.07
Soyuz 34	8 June 1979	23:02	rear	14 June 1979	19:18	5.84
Soyuz 34	14 June 1979	~19:50	front	19 August 1979	12:08	65.86
Progress 7	30 June 1979	14:18	rear	18 July 1979	06:50	17.69
Soyuz T-1	19 December 1979	17:05	front	24 March 1980	00:04	94.29
Progress 8	29 March 1980	23:01	rear	25 April 1980	11:04	26.50
Soyuz 35	10 April 1980	18:16	front	3 June 1980	14:47	53.85
Progress 9	29 April 1980	11:09	rear	20 May 1980	21:51	21.45
Soyuz 36	27 May 1980	22:56	rear	4 June 1980	18:08	7.86
Soyuz 36	4 June 1980	19:38	front	31 July 1980	14:55	56.86
Soyuz T-2	6 June 1980	18:58	rear	9 June 1980	12:24	2.73
Progress 10	1 July 1980	08:53	rear	18 July 1980	01:21	16.69
Soyuz 37	24 July 1980	23:02	rear	1 August 1980	19:43	7.86
Soyuz 37	1 August 1980	~20:10	front	11 October 1980	09:30	70.56
Soyuz 38	19 September 1980	20:49	rear	26 September 1980	12:35	6.62
Progress 11	30 September 1980	20:03	rear	9 December 1980	13:23	69.72
Soyuz T-3	28 November 1980	18:54	front	10 December 1980	09:10	11.59
Progress 12	26 January 1981	18:56	rear	19 March 1981	21:14	52.09
Soyuz T-4	13 March 1981	23:33	front	26 May 1981	–	~74
Soyuz 39	23 March 1981	19:28	rear	30 March 1981	11:22
Soyuz 40	15 May 1981	21:50	rear	22 May 1981	13:37	6.66
Kosmos 1267	19 June 1981	10:52	front	permanently docked	–	–

Dates and times are 24-hour Moscow Time. Source:[1]

Station crews

Expedition	Crew	Launch date	Flight up	Landing date	Flight down	Duration (days)
Salyut 6 - EO-1	Yuri Romanenko, Georgy Grechko	10 December 1977 01:18:40	Soyuz 26	16 March 1978 11:18:47	Soyuz 27	96.42
Salyut 6 - EP-1	Vladimir Dzhanibekov, Oleg Makarov	10 January 1978 12:26:00	Soyuz 27	16 January 1978 11:24:58	Soyuz 26	5.96
Salyut 6 - EP-2	Aleksei Gubarev, Vladimír Remek – Czechoslovakia	2 March 1978 15:28:00	Soyuz 28	10 March 1978 13:44:00	Soyuz 28	7.93
Salyut 6 - EO-2	Vladimir Kovalyonok, Aleksandr Ivanchenkov	15 June 1978 20:16:45	Soyuz 29	2 November 1978 11:04:17	Soyuz 31	139.62
Salyut 6 - EP-3	Pyotr Klimuk, Mirosław Hermaszewski – Poland	27 June 1978 15:27:21	Soyuz 30	5 July 1978 13:30:20	Soyuz 30	7.92
Salyut 6 - EP-4	Valery Bykovsky, Sigmund Jähn – German Democratic Republic	26 August 1978 14:51:30	Soyuz 31	3 September 1978 11:40:34	Soyuz 29	7.87
Salyut 6 - EO-3	Vladimir Lyakhov, Valery Ryumin	25 February 1979 11:53:49	Soyuz 32	19 August 1979 12:29:26	Soyuz 34	175.02
Salyut 6 - EO-4	Leonid Popov, Valery Ryumin	9 April 1980 13:38:22	Soyuz 35	11 October 1980 09:49:57	Soyuz 37	184.84
Salyut 6 - EP-5	Valery Kubasov, Bertalan Farkas – Hungary	26 May 1980 18:20:39	Soyuz 36	3 June 1980 15:06:23	Soyuz 35	7.87
Salyut 6 - EP-6	Yury Malyshev, Vladimir Aksyonov	5 June 1980 14:19:30	Soyuz T-2	9 June 1980 12:39:00	Soyuz T-2	3.93
Salyut 6 - EP-7	Viktor Gorbatko, Pham Tuan – Vietnam	23 July 1980 18:33:03	Soyuz 37	31 July 1980 15:15:02	Soyuz 36	7.86
Salyut 6 - EP-8	Yuri Romanenko, Arnaldo Tamayo Méndez – Cuba	18 September 1980 19:11:03	Soyuz 38	26 September 1980 15:54:27	Soyuz 38	7.86
Salyut 6 - EO-5	Leonid Kizim, Oleg Makarov Gennady Strekalov	27 November 1980 14:18:28	Soyuz T-3	10 December 1980 09:26:10	Soyuz T-3	12.80
Salyut 6 - EO-6	Vladimir Kovalyonok, Viktor Savinykh	12 March 1981 19:00:11	Soyuz T-4	26 May 1981 12:37:34	Soyuz T-4	74.73
Salyut 6 - EP-9	Vladimir Dzhanibekov, Jügderdemidiin Gürragchaa – Mongolia	22 March 1981 14:58:55	Soyuz 39	30 March 1981 11:40:58	Soyuz 39	7.86
Salyut 6 - EP-10	Leonid Popov, Dumitru Prunariu – Romania	14 May 1981 17:16:38	Soyuz 40	22 May 1981 13:58:30	Soyuz 40	7.86

Dates and times are 24-hour Coordinated Universal Time.

Spacewalks

EVA	Spacewalkers	Date	EVA Start	EVA End	Duration (hours)	Comments
Salyut 6 – PE-1	Yuri Romanenko and Georgy Grechko	19 December 1977	21:36	23:04	1:28	Test of Orlan-D spacesuit, inspection of docking apparatus and Medusa cassette deployment.
Salyut 6 – PE-2	Vladimir Kovalyonok and Aleksandr Ivanchenkov	29 July 1978	04:00	06:20	2:05	Retrieval of Medusa cassette and passive micrometeoroid detector, deployment of radiation detector & new experimental cassettes.
Salyut 6 – PE-3	Valery Ryumin and Vladimir Lyakhov	15 August 1979	14:16	15:39	1:23	Removal of KRT-10 radio telescope dish, retrieval of experiment cassettes.

Dates and times are 24-hour Coordinated Universal Time. Source:[1]

See also

• Timeline of longest spaceflights

References

1. Harland, David (14 February 2005). The Story of Space Station Mir. Glasgow, United Kingdom: Springer-Praxis. ISBN 978-0-387-23011-5.
2. "NASA – NSSDC – Spacecraft – Details". NASA. 2 April 2008. Retrieved 29 June 2008.
3. Baker, Philip (1 June 2007). The Story of Manned Space Stations: An Introduction. New York, United States of America: Springer-Praxis. ISBN 978-0-387-30775-6.
4. Wade, Mark. "Salyut 6". Encyclopedia Astronautica. Retrieved 5 July 2007.
5. Hall & Shayler (7 May 2003). Soyuz: A Universal Spacecraft. London, United Kingdom: Springer-Praxis. ISBN 978-1-85233-657-8.
6. David S. F. Portree (March 1995). "Mir Hardware Heritage" (PDF). NASA. Archived from the original (PDF) on 3 August 2009. Retrieved 30 March 2007. Cite journal requires |journal= (help) This article incorporates text from this source, which is in the public domain.
7. Wade, Mark. "Cosmos 1267". Encyclopedia Astronautica. Archived from the original on 8 August 2007. Retrieved 28 June 2007.