Soyuz 21
| COSPAR ID | 1976-064A |
|---|---|
| Mission duration | 49 days, 6 hours, 23 minutes, 32 seconds |
| Orbits completed | 790 |
| Spacecraft properties | |
| Spacecraft type | Soyuz 7K-T/A9 |
| Manufacturer | NPO Energia |
| Launch mass | 6,800 kilograms (15,000 lb) |
| Crew | |
| Crew size | 2 |
| Members |
Boris Volynov Vitaly Zholobov |
| Callsign | Байкал (Baikal - "Lake Baikal") |
| Start of mission | |
| Launch date | July 6, 1976, 12:08:45 UTC |
| Rocket | Soyuz |
| Launch site | Baikonur 1/5 |
| End of mission | |
| Landing date | August 24, 1976, 18:32:17 UTC |
| Landing site | 200 kilometres (120 mi) SW of Kokchetav |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Low Earth |
| Perigee | 246 kilometres (153 mi) |
| Apogee | 274 kilometres (170 mi) |
| Inclination | 51.6 degrees |
| Period | 89.7 minutes |
| Docking with Salyut 5 | |
|
Soyuz programme
(Manned missions) |
|
Soyuz 21 (Russian: Союз 21, Union 21) was a 1976 Soviet manned mission to the Salyut 5 space station, the first of three flights to the station. The mission's objectives were mainly military in scope, but included other scientific work. The mission ended abruptly with cosmonauts Boris Volynov and Vitaly Zholobov returning to earth after 49 days in orbit. The precise reason for the early end of the mission was the subject of much speculation, but was reported to be an emergency evacuation after the Salyut atmosphere developed an acrid odor.
Salyut 5, the last dedicated military space station in the Soviet space program, was launched 22 June 1976. Its first crew was launched 14 days later on 6 July, with Commander Volynov and Flight Engineer Zholobov aboard Soyuz 21. Based on landing opportunities, observers estimated the mission was intended to last 54 to 66 days. They docked with the station the next day, and gave a televised tour 8 July.
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 operation of the freight-carrying Progress spacecraft.
Experiments conducted during the mission were mainly of a military nature as part of the Almaz program. Various purely scientific tasks were also carried out, including solar observations and biological observations of an aquarium of fish carried into orbit. A TV link-up with school children on 17 August was also undertaken.
On 24 August, it was announced the mission was to end in only 10 hours, a development which caught even the reporters of Radio Moscow by surprise. The reason for the sudden termination of the mission was reported at the time to have been an acrid odor that developed in the environmental control system. The problem was said to have begun as early as 17 August. The Soviets made no comments at the time, but the next crew to board the station wore breathing masks. Later reports indicate that the mission may have ended owing to a deterioration in the health of Zholobov.
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