Soyuz 20

Soyuz 20

Mission type	Orbital test flight
Operator	Soviet space program
COSPAR ID	1975-106A
SATCAT no.	8430
Mission duration	90 days, 11 hours and 47 minutes
Orbits completed	1470
Spacecraft properties
Spacecraft	Soyuz 7K-T No.8
Spacecraft type	Soyuz 7K-T/A9
Manufacturer	NPO Energia
Launch mass	6,570 kg (14,480 lb)
Landing mass	2,800 kg (6,200 lb)
Start of mission
Launch date	17 November 1975, 14:36:37 UTC
Rocket	Soyuz-U
Launch site	Baikonur 1/5
End of mission
Landing date	16 February 1976, 02:24 UTC
Landing site	56 km at the southwest of Arkalyk, Kazakhstan
Orbital parameters
Reference system	Geocentric orbit
Regime	Low Earth orbit
Perigee altitude	199.7 km (124.1 mi)
Apogee altitude	263.5 km (163.7 mi)
Inclination	51.6°
Period	88.8 minutes
Docking with Salyut 4
Docking date	19 November 1975, 16:19 UTC
Undocking date	16 February 1976, 23:07 UTC
Time docked	89 days, 6 hours and 48 minutes
Soyuz programme

Soyuz 20 (Russian: Союз 20, Union 20) was an uncrewed spacecraft launched by the Soviet Union. It was a long-duration test of the Soyuz spacecraft that docked with the Salyut 4 space station. Soyuz 20 performed comprehensive checking of improved on-board systems of the spacecraft under various flight conditions. It also carried a biological payload. Living organisms were exposed to three months in space. The primary goal of the mission was to test hardware modifications to the Soyuz 7K-T spacecraft that would extend its operating life from two to three months in preparation for long-duration Salyut crew residencies.

Mission parameters

• Mass: 6,570 kg (14,480 lb)
• Perigee: 199.7 km (124.1 mi)
• Apogee: 263.5 km (163.7 mi)
• Inclination: 51.6°
• Period: 88.8 minutes

Return

It was recovered on 16 February 1976 at 02:24 UTC.