|Mission duration||29 days, 13 hours, 19 minutes, 45 seconds|
|Spacecraft type||Soyuz 7K-T|
|Launch mass||6,800 kilograms (15,000 lb)|
|Callsign||Зенит (Zenit - "Zenith")|
|Start of mission|
|Launch date||January 10, 1975, 21:43:37UTC|
|Launch site||Baikonur 1/5|
|End of mission|
|Landing date||February 9, 1975, 11:03:22UTC|
|Landing site||110 kilometres (68 mi) NE of Tselinograd|
|Perigee||185 kilometres (115 mi)|
|Apogee||249 kilometres (155 mi)|
|Docking with Salyut 4|
Soyuz 17 (Russian: Союз 17, Union 17) was the first of two long-duration missions to the Soviet Union's Salyut 4 space station in 1975. The flight set a Soviet mission-duration record of 29 days, surpassing the 23-day record set by the ill-fated Soyuz 11 crew aboard Salyut 1 in 1971.
|Flight Engineer||Georgi Grechko
|Flight Engineer||Oleg Makarov|
|Flight Engineer||Vitali Sevastyanov|
- Mass: 6,800 kg (15,000 lb)
- Perigee: 185 km (115 mi)
- Apogee: 249 km (155 mi)
- Inclination: 51.6°
- Period: 88.8 min
Salyut 4 was launched 26 December 1974, and Soyuz 17, with cosmonauts Georgi Grechko and Aleksei Gubarev as its first crew, was launched 16 days later on 10 January 1975. Gubarev manually docked Soyuz 17 to the station on 12 January, and upon entering the new station he and Grechko found a note from its builders which said, "Wipe your feet!"
Salyut 4 was in an unusually high circular orbit of 350 km (220 mi) when Soyuz 17 docked with the station. Salyut designer Konstantin Feoktistov said this was to ensure propellant consumption would be half of what was needed for lower-altitude Salyuts.
The crew worked between 15 and 20 hours a day, including their 2 1⁄2 hour exercise period. One of their activities included testing communication equipment for tracking ships and contacting mission control via a Molniya satellite.
Astrophysics was a major component of the mission, with the station's solar telescope activated on 16 January. The crew later discovered that the main mirror of the telescope had been ruined by direct exposure to sunlight when the pointing system failed. They resurfaced the mirror on 3 February and worked out a way of pointing the telescope using a stethoscope, stopwatch, and the noises the moving mirror made in its casing.
On 14 January, a ventilation hose was set up from Salyut 4 to keep the Soyuz ventilated while its systems were shut down. On 19 January it was announced that ion sensors were being used to orient the station, a system described as being more efficient.
The cosmonauts began powering down the station on 7 February and they returned to Earth in the Soyuz capsule two days later. They safely landed near Tselinograd in a snowstorm with winds of 72 km/h and wore gravity suits to ease the effects of re-adaptation.
- "Baikonur LC1". Encyclopedia Astronautica. Retrieved 2009-03-04.
- Newkirk, Dennis (1990). Almanac of Soviet Manned Space Flight. Houston, Texas: Gulf Publishing Company. ISBN 0-87201-848-2.
- Clark, Phillip (1988). The Soviet Manned Space Program. New York: Orion Books, a division of Crown Publishers, Inc. ISBN 0-517-56954-X.