Soyuz T-4
COSPAR ID1981-023A Edit this at Wikidata
SATCAT no.12334
Mission duration74 days, 17 hours, 37 minutes, 23 seconds
Orbits completed1,178
Spacecraft properties
Spacecraft typeSoyuz-T
ManufacturerNPO Energia
Launch mass6,850 kilograms (15,100 lb)
Crew size2
MembersVladimir Kovalyonok
Viktor Savinykh
Start of mission
Launch date12 March 1981, 19:00:11 (1981-03-12UTC19:00:11Z) UTC
Launch siteBaikonur 1/5
End of mission
Landing date26 May 1981, 12:37:34 (1981-05-26UTC12:37:35Z) UTC
Landing site125 kilometres (78 mi) E Dzhezkazgan
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee altitude201 kilometres (125 mi)
Apogee altitude250 kilometres (160 mi)
Inclination51.6 degrees
Period88.7 minutes
Docking with Salyut 6
Docking date13 March 1981, 20:33 (1981-03-13UTC20:33Z) UTC[1]
Undocking date26 May 1981, 09:20 (1981-05-26UTC09:21Z) UTC[1]
Soyuz programme
(Crewed missions)

Soyuz T-4 was a Soviet space mission which launched the crew of Salyut 6 EO-6, the sixth and final long-duration crew of the Salyut 6 space station. It was launched on 12 March 1981 and docked with the station the next day.[1] During their stay, the EO-6 crew was visited by Soyuz 39 and Soyuz 40. Soyuz T-4 returned to Earth on 26 May 1981; its crew were the last to have inhabited Salyut 6.[2]


Position Crew
Commander Soviet Union Vladimir Kovalyonok
Third and last spaceflight
Flight Engineer Soviet Union Viktor Savinykh
First spaceflight

Backup crew

Position Crew
Commander Soviet Union Vyacheslav Zudov
Flight Engineer Soviet Union Boris Andreyev

Mission parameters

Mission highlights

The docking with Salyut 6 was delayed after the Soyuz's onboard Argon computer determined it would occur outside radio range with the TsUP.[3] Despite this, the docking occurred successfully on 13 March 1981. The Progress 12 spacecraft was already docked to the station by the time the crew arrived, and they spent several days unloading the Progress before its undocking on 19 March.[1] This freed the remaining docking port for the arrival of the Soyuz 39/EP-9 crew on 22 March.

In mid-May, Kovalyonok and Savinykh replaced the spacecraft's probe with a Salyut drogue. This may have been an experiment to see if a Soyuz-T docked to a space station could act as a rescue vehicle in the event that an approaching Soyuz-T equipped with a probe experienced docking difficulties and could not return to Earth.[1]

The EO-6 crew undocked from Salyut 6 on 26 May, leaving behind the Soyuz's orbital module. Soyuz T-4 landed over three hours later, touching down 125 kilometres (78 mi) east of Dzhezkazgan, Kazakh SSR.[1]

See also


  1. ^ a b c d e f "Soyuz T-4". Spacefacts. 24 November 2013. Retrieved 24 March 2014.
  2. ^ Yenne, Bill (1988). The Pictorial History of World Spaceflight. Exeter. pp. 140, 143. ISBN 0-7917-0188-3.
  3. ^ D. S. F. Portree (1995). "Mir Hardware Heritage" (PDF). NASA. p. 49. Archived from the original (PDF) on 2003-07-09.