Soyuz 21

Infobox Space mission
mission_name = Soyuz 21
sign = Байкал (Baikal - "Lake Baikal")
crew_members = 2
launch = July 6, 1976
12:08:45 UTC
Gagarin's Start
landing = August 24, 1976
18:32:17 UTC
200 km SW of Kokchetav
duration = 49d/06:23:32
orbits = 790
next = Soyuz 22
previous = Soyuz 20 |

Soyuz 21 carried cosmonauts Boris Volynov and Vitali Zholobov, to the Salyut 5 space station.

Crew

Number in parentheses indicates number of spaceflights by each individual prior to and including this mission.
*Boris Volynov (2) - Commander
*Vitali Zholobov (1) - Flight Engineer

Backup crew

*Vyacheslav Zudov - Commander
*Valeri Rozhdestvensky - Flight Engineer

Reserve crew

*Viktor Gorbatko - Commander
*Yuri Glazkov - Flight Engineer

Mission parameters

*Mass: 6800 kg (14,990 lb)
*Perigee: 246 km (153 mi)
*Apogee: 274 km (170 mi)
*Inclination: 51.6°
*Period: 89.7 min

Mission highlights

On 6 July 1976 Volynov and Flight Engineer Zholobov were launched on board Soyuz 21 to spend 18 days aboard the space station Salyut 5. Their stay coincided with the start of the Siber military exercise in Siberia, which they observed as part of an assessment of the station’s military surveillance capabilities. They conducted only a few scientific experiments, including the first use of the Kristall furnace for crystal growth. Engineering experiments included propellant transfer system tests with implications for future Progress freighter operations.

Experiments conducted during the mission were mainly of a military nature as part of the Almaz programme. However, various purely scientific tasks were also carried out, including solar observations and biological observations (an aquarium of fish was carried into orbit). A TV link-up with school children was also undertaken.

Following a deterioration in the health of Zholobov, who was making his first spaceflight, the decision was made to return the crew at the earliest available opportunity and they boarded Soyuz 21 on 24 August. However, as Volynov tried to undock from Salyut 5, the latch failed to release properly. As he fired the jets to move the spacecraft away, the docking mechanism jammed, resulting in the Soyuz being undocked but still linked to Salyut. As the two spacecraft moved out of range of ground communications, only the first set of emergency procedures was received. Volynov tried a second time to undock but only managed to slightly loosen the latches. This situation persisted for an entire orbit (90 minutes), then the final set of emergency procedures were received and the latches finally disengaged.

Because Soyuz 21 was returning early it was outside the normal recovery window, and encountered strong winds as it descended, which caused uneven firing of the retrorockets. It made a hard landing around midnight 200 km southwest of Kokchetav, Kazakhstan. Zholobov's illness was apparently caused by nitric acid fumes leaking from the Salyut's propellant tanks. However, other reports indicate that the crew failed to properly follow their physical exercise program and suffered from lack of sleep. [cite book | last = Hall | first = Rex | authorlink = | coauthors = David Shayler | title = Soyuz: A Universal Spacecraft | publisher = Springer | date = 2003 | location = | pages = pp. 195-196 | url = | doi = | id = | isbn = 1852336579]

Notes

References

*cite web | last = | first = | authorlink = | coauthors = | title = Voskhod 1 | work = Encyclopedia Astronautica | publisher = | date = | url = http://www.astronautix.com/flights/voskhod1.htm | format = | doi = | accessdate = 2008-08-10