Soyuz 7K-OKS


Soyuz 7K-OKS
Soyuz 7K-OKS spacecraft
ManufacturerExperimental Design Bureau
Country of originSoviet Union
OperatorSoviet space program
ApplicationsCrewed spacecraft to dock with space station
7.94 metres (26.0 ft)
9,000 cubic metres (320,000 cu ft)
RegimeLow Earth orbit
Design lifeUp to 35 days
StatusNo longer in service
Maiden launchSoyuz 10
22 April 1971
Last launchSoyuz 11
6 June 1971
Related spacecraft
Derived fromSoyuz 7K-OK

Soyuz 7K-OKS (also known as Soyuz 7KT-OK)[1] is a version of the Soyuz spacecraft and was the first spacecraft designed for space station flights. Its only crewed flights were conducted in 1971, with Soyuz 10 and Soyuz 11.


The two craft of the Soyuz 7K-OKS generation were modified from the original Soyuz 7K-OK. The new "probe and drogue" docking mechanism, which was first used by these two missions, featured an internal docking hatch that allowed for the first time internal transfer between Soviet spacecraft. This "probe and drogue" docking mechanism introduced with Soyuz 7K-OKS is still in use today at the International Space Station (ISS). The external toroidal fuel tank, a holdover from the original lunar mission models of the Soyuz, was dropped from the 7K-OKS since it was unneeded for Earth orbital flights.[1]


The Soyuz 7K-OKS flew only twice, Soyuz 10 and Soyuz 11.[1]

On its maiden flight, the Soyuz 7K-OKS successfully launched into Earth orbit, but failed to dock completely with the Salyut 1 space station. Upon reentry, the spacecraft encountered problems with toxic fumes.[2]

This generation of Soyuz spacecraft is notable for the first successful delivery of crew to the first space station Salyut 1 by Soyuz 11 – this success was however overshadowed by the death of the crew, who were killed when the capsule depressurised during the re-entry phase.[3]



  1. ^ a b c "Soyuz 7KT-OK". Astronautix. Archived from the original on 3 January 2010. Retrieved 8 November 2010.
  2. ^ "Soyuz 10". Astronautix. Archived from the original on 5 May 2009. Retrieved 8 November 2010.
  3. ^ "Soyuz 11 1971-053A". NASA. 14 May 2020. Retrieved 6 October 2020. Public Domain This article incorporates text from this source, which is in the public domain.

External links

  • Russia New Russian spaceship will be able to fly to Moon - space corp
  • RSC Energia: Concept Of Russian Manned Space Navigation Development
  • Mir Hardware Heritage
    • David S.F. Portree, Mir Hardware Heritage, NASA RP-1357, 1995
    • Mir Hardware Heritage (wikisource)
  • Information on Soyuz spacecraft
  • OMWorld's ASTP Docking Trainer Page
  • NASA - Russian Soyuz TMA Spacecraft Details
  • Space Adventures circum-lunar mission - details