Soyuz T-15

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**Soyuz T-15**
Mission statistics
Mission name:	Soyuz T-15
Call sign:	Mayak (Beacon)
Number of crew members:	2
Launch:	March 13, 1986 12:33:09 UTC Baikonur LC1
Landing:	July 16, 1986 12:34:05 UTC 55 km NE of Arkalyk
Duration:	125 days, 56 seconds
Number of Orbits:	1980

[edit] Crew

Leonid Kizim (3)
Vladimir Soloviyov (2)

(1) number of spaceflights each crew member has completed, including this mission.

[edit] Mission parameters

Mass: 6850 kg
Perigee: 331 km
Apogee: 366 km
Inclination: 51.6°
Period: 91.5 minutes

[edit] Mission highlights

Soyuz T-15 was the first expedition to Mir. It left Mir, visited Salyut 7 and then returned again to Mir.

Carried the first two cosmonauts to the Mir station. May 5-6 they transferred to Salyut 7, where they conducted two EVAs and collected experiment results, experimental apparatus, and samples of materials. The Mayaks loaded Soyuz T-15 with their personal belongings, plants grown on Mir, and other items in preparation for the trip to Salyut 7, which was about 4000 km ahead of Mir in a lower orbit. On May 4 Mir was lowered by 13 km to speed the approach to Salyut 7 and conserve Soyuz T-15's limited fuel supply for the transfer. Soyuz T-15 separated from Mir when Salyut 7 was 2500 km away. The crossing required 29 h. They returned to Mir on June 25-26. Mir maneuvered twice June 24-25, raising its orbit slightly and moving closer to Salyut 7. On June 25 Soyuz T-15 undocked from Salyut 7 and began the 29 h journey back to Mir.

Vasyutin's illness had left loose ends on Salyut 7. Most notably, the Chegets were unable to perform EVAs with implications for the Mir program. On May 28 the Mayaks climbed outside to retrieve space exposure experiments and test the Ferma-Postroital ("girder-constructor") device. A deployment canister converted a folded girder cartridge into a 15-m girder in only a few minutes. The girder was retracted by reversing the process at the end of the EVA. The EVA lasted 3 h 50 min. Second EVA - girder and welding experiments. On May 31 Kizim and Solovyov attached measurement devices to the top of the retracted girder, then re-extended it with an aim toward studying its rigidity. They then used an electron gun to weld several of the girder's joints. The EVA lasted 5 hr.

The Mayaks removed 20 instruments with a total mass of 350 to 400 kg from Salyut 7 before returning to Mir. Between August 19 and August 22, engines on Cosmos 1686 boosted Salyut 7 to a record-high mean orbital altitude of 475 km to forestall reentry. Atmospheric drag took its toll, however, and the station reentered over South America 55 months later. Pieces of Salyut 7 and Cosmos 1686 were found in Argentina.

The Soviets intended to dock Soyuz T-15 with Mir's forward port, leaving the aft port free for arriving Progress spacecraft. However, Soyuz T-15, like its Soyuz-T precursors, was equipped with the Igla approach system, not the Kurs system used on Mir's front port. Soyuz T-15 approached Mir from behind. At 20 km Soyuz T-15's Igla system acquired its counterpart on Mir's aft port. At 200 m the Igla system was shut off, and the Mayaks manually maneuvered around the station to dock at the front port. They used the same laser range finder used by Soyuz T-13 to dock with the uncooperative Salyut 7 station in 1985.

Soyuz T-15 arrived at Mir with a cargo of 350- 400 kg of instruments from Salyut 7. On July 3 Kizim surpassed Valeri Ryumin's record for time spent in space. On July 6 he became the first human to spend a full year in space. The Mayaks spent their last 20 days on Mir conducting Earth observations.