Status No longer in service Launched 16 | Built 16 | |
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Applications Carry three cosmonauts to orbit and back Manufacturer S. P. Korolev Rocket and Space Corporation Energia Similar Soyuz 7K‑T, Soyuz 7K‑L1, Soyuz 7K‑LOK, Soyuz‑T, Soyuz‑TM |
Soyuz 7k ok digital 3d study
Soyuz 7K-OK was the first generation of Soyuz spacecraft in use from 1967 to 1971. This first generation was used for the first ferry flights to in the Salyut space station program; Soyuz spacecraft in their current generation are still in use to ferry crew to and from the ISS.
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This generation is notable for the only fatalities of the Soyuz programme as of 2016, with Soyuz 1 in 1967 (sole crew-member killed by parachute failure) and Soyuz 11 in 1971 (crew killed by depressurisation during reentry).

The first unmanned automated docking in the history of spaceflight, between Kosmos 186 and Kosmos 188 in 1967, was achieved with this generation of Soyuz spacecraft. The generation encompasses furthermore the first docking between two manned spacecraft (Soyuz 4 and Soyuz 5), the longest manned flight involving only one spacecraft (the 18-day flight of Soyuz 9 in 1970) and the first successful manning of the first space station in the history of space flight (Soyuz 11 and Salyut 1 in 1971).

The Soyuz 7K-OK vehicles carried a crew of up to three without spacesuits. The craft can be distinguished from those following by their bent solar panels and their use of the Igla automatic docking navigation system, which required special radar antennas.

The 7K-OK was primarily intended as a variant of the 7K-LOK (the lunar mission Soyuz) for Earth orbital testing. Mostly the same vehicle, it lacked the larger antenna needed to communicate at lunar distance. The early Soyuz models also sported an external toroidal fuel tank surrounding the engines and meant to store extra propellant for lunar flights, but it was left empty on Soyuz 1-9. After the spacecraft was converted to a space station ferry, the tank was removed.

Soyuz 7K-OK spacecraft had a "probe and drogue" docking mechanism to connect with other spacecraft in orbit, in order to gather engineering data as an preparation for the Soviet space station program. There were two variants of Soyuz 7K-OK: Soyuz 7K-OK(A) featuring an active "probe" docking port, and Soyuz 7K-OK(P) featuring a passive "drogue" docking target. The docking mechanisms of 7K-OK and 7K-LOK did not allow internal transfer (this feature was added on the 7K-OKS version), thus cosmonauts had to spacewalk between docked modules. This procedure was conducted successfully on the joint Soyuz 4 and Soyuz 5 missions, where Aleksei Yeliseyev and Yevgeny Khrunov transferred from their Soyuz 5 to the Soyuz 4 craft.

The first unmanned test of this version was Kosmos 133, launched on November 28, 1966.
Soyuz 7K-OKS

The last two Soyuz space craft of this series were of the designation Soyuz 7K-OKS. In contrast to Soyuz 7K-OK, which docking mechanism lacked a hatch for internal crew transfer, the Soyuz 7K-OKS spacecraft were modified to utilize the new SSVP docking system that allowed internal crew transfer – this was performed for the first time with the manning of the Salyut 1 space station by Soyuz 11. The SSVP docking adapter is still in use until today at the ISS.