Soyuz 7K-OKS (also known as Soyuz 7KT-OK) is a version of the

Soyuz spacecraft Soyuz () is a series of spacecraft which has been in service since the 1960s, having made more than 140 flights. It was designed for the Soviet space program by the Korolev Design Bureau (now Energia). The Soyuz succeeded the Voskhod spacecraf ...

and was the first spacecraft designed for

space station A space station (or orbital station) is a spacecraft which remains orbital spaceflight, in orbit and human spaceflight, hosts humans for extended periods of time. It therefore is an artificial satellite featuring space habitat (facility), habitat ...

flights. Its only crewed flights were conducted in 1971, with Soyuz 10 and Soyuz 11.

Design

The two craft of the Soyuz 7K-OKS generation were modified from the original

Soyuz 7K-OK Soyuz 7K-OK was the first generation of Soyuz spacecraft and was flown between 1967 and 1971. The 7K-OK was used for the first ferry flights to the Salyut space station program, beginning a long history of space station service that continue ...

. 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 The International Space Station (ISS) is a large space station that was Assembly of the International Space Station, assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United ...

(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.

Flights

The Soyuz 7K-OKS flew only twice, Soyuz 10 and Soyuz 11. On its maiden flight, the Soyuz 7K-OKS successfully launched into Earth orbit, but failed to dock completely with the

Salyut 1 Salyut 1 (), also known as DOS-1 (Durable Orbital Station 1), was the world's first space station. It was launched into low Earth orbit by the Soviet Union on April 19, 1971. The Salyut programme, ''Salyut'' program subsequently achieved five m ...

space station. Upon reentry, the spacecraft encountered problems with toxic fumes. This generation of Soyuz spacecraft is notable for the first successful delivery of crew to the first space station

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 Atmospheric entry (sometimes listed as Vimpact or Ventry) is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. Atmospheric entry may be ''uncontrolled entry ...

phase.

Missions

References

External links

RSC Energia: Concept Of Russian Manned Space Navigation Development
* Mir Hardware Heritage ** David S.F. Portree,

', NASA RP-1357, 1995 ** Mir Hardware Heritage (wikisource)
Information on Soyuz spacecraft

{{Russian human spaceflight programs Crewed spacecraft Soyuz program Vehicles introduced in 1971