The Soyuz 7K-LOK, or simply LOK (russian: Лунный Орбитальный Корабль, translit=Lunniy Orbitalny Korabl meaning "Lunar Orbital Craft") was a

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

crewed spacecraft designed to launch men from Earth to orbit the Moon, developed in parallel to the 7K-L1. The LOK would carry two cosmonauts, acting as a mother ship for the LK Lander which would land one crew member to the surface. It was part of the

N1-L3 The Soviet crewed lunar programs were a series of programs pursued by the Soviet Union to land humans on the Moon, in competition with the United States Apollo program. The Soviet government publicly denied participating in such a competitio ...

programme which also included the LK lander and the N1 rocket.

Design

Like the 7K-OK model, the 7K-LOK was divided into three sections, an ellipsoid Orbital Module, the "headlight"-shaped Descent Module, and a cylindrical equipment module. Like the 7K-OK, the 7K-LOK was capable of physically docking with another spacecraft, but lacked the transfer tunnel used on the

Apollo (spacecraft) The Apollo spacecraft was composed of three parts designed to accomplish the American Apollo program's goal of landing astronauts on the Moon by the end of the 1960s and returning them safely to Earth. The expendable (single-use) spacecraft ...

, thus forcing the cosmonaut to make a

spacewalk Extravehicular activity (EVA) is any activity done by an astronaut in outer space outside a spacecraft. In the absence of a breathable Earthlike atmosphere, the astronaut is completely reliant on a space suit for environmental support. EVA in ...

from the 7K-LOK's orbital module to the LK Lander using the new Krechet space suit (the predecessor to the Orlan space suits used today on the

International Space Station The International Space Station (ISS) is the largest Modular design, modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos ( ...

). Another change to the 7K-LOK was the elimination of the solar panels used on the 7K-OK, replacing them with

fuel cells A fuel cell is an electrochemical cell that converts the chemical energy of a fuel (often hydrogen) and an oxidizing agent (often oxygen) into electricity through a pair of redox reactions. Fuel cells are different from most batteries in requ ...

similar to those found on the Apollo CSM. Another feature, a "cupola" located on the Orbital Module, allowed the cosmonaut in the 7K-LOK to perform the docking procedure with the LK Lander after lunar liftoff. Only the Descent Module from the 7K-L1, with a thicker, reinforced heatshield, is used on the 7K-LOK and like the 7K-L1, is capable of doing a "

skip reentry Non-ballistic atmospheric entry is a class of atmospheric entry trajectories that follow a non- ballistic trajectory by employing aerodynamic lift in the high upper atmosphere. It includes trajectories such as skip and glide. Skip is a flight ...

" so that the Soyuz could be recovered in the Soviet Union. The information display systems (IDS) on the LOK were different from those of the Soyuz-7K. The Descent Module was equipped with the "Uran" control panel and the Orbital Module featured the "Orion" approach control panel.

Flights

Only three uncrewed 7K-LOKs were flown in the short lifespan of the failed Soviet lunar program. *One of them was a dummy 7K-LOK as a Soyuz 7K-L1E modification of a Soyuz 7K-L1 "Zond" spacecraft and was successfully test launched into

Low Earth orbit A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never m ...

on a

Proton rocket Proton (Russian: Протон) (formal designation: UR-500) is an expendable launch system used for both commercial and Russian government space launches. The first Proton rocket was launched in 1965. Modern versions of the launch system are sti ...

designated as Kosmos 382 (Soyuz 7K-L1E No.2) on December 2, 1970. *Two other unsuccessful launches of dummy 7K-LOK ( Soyuz 7K-L1E No.1) and operational ( Soyuz 7K-LOK No.1) with dummy LKs were fulfilled atop the N-1 rocket in its later flights on June 26, 1971 and November 23, 1972 intended for lunar flybys. Both spacecraft were pulled and saved by the

launch escape system A launch escape system (LES) or launch abort system (LAS) is a crew-safety system connected to a space capsule that can be used to quickly separate the capsule from its launch vehicle in case of an emergency requiring the abort of the launch, s ...

when those boosters failed. The two aborted flights later proved that the launch-escape system worked when a similar problem on a

Soyuz-U The Soyuz-U launch vehicle was an improved version of the original Soyuz rocket. Soyuz-U was part of the R-7 family of rockets based on the R-7 Semyorka missile. Members of this rocket family were designed by the TsSKB design bureau and cons ...

forced the

Soyuz T-10a Soyuz 7K-ST No.16L, sometimes known as Soyuz T-10a or Soyuz T-10-1, was an unsuccessful Soyuz mission intended to visit the Salyut 7 space station, which was occupied by the Soyuz T-9 crew. However, it never finished its launch countdown; the ...

to be jettisoned with its cosmonaut crew in 1983 before the booster exploded on the launchpad, destroying it. On two early flights of the N-1, both of them failures, another

Soyuz 7K-L1S Zond L1S-1 was a Zond capsule to be placed into orbit around the Moon by the first launch of the N1, a Soviet made super heavy-lift launch vehicle designed to land manned Soviet spacecraft on the Moon. The Zond capsule was equipped with a dum ...

"Zond-M" modification of the 7K-L1 spacecraft instead of the 7K-LOK or 7K-L1E were used without the dummy LK, and they, along with the booster, were destroyed. *Subsequently, a complete L3 lunar expedition complex with an operational 7K-LOK and LK, LOK 2, for an uncrewed lunar flyby and landing mission (in preparation of a future crewed flight) was prepared for the fifth launch of a modified N1 rocket in August 1974. The

program was cancelled in May 1974 and the Soviets decided to concentrate on the development of space stations, achieving several firsts in the process.

References

External links

LOK spacecraft article
{{DEFAULTSORT:Soyuz 7k-LOK Crewed spacecraft Soyuz program Cancelled Soviet spacecraft Soviet lunar program