The Core Module
of the Mir space station

On February 20, 1986, the UR-500K (Proton) rocket launched the core module the space station called Mir, which can be translated as "peace" or "world." The official Soviet news reports, released immediately after the launch, said that the spacecraft is equipped with six docking ports and it will serve as a core of the future multi-modular orbital station.


Ground copy of Mir's core module (foreground) and the Kvant-1 module.

According to Roskosmos, the development work on the Mir orbital complex began in 1976 and involved 280 organizations with 20 different Soviet ministries.

Although the core module, known in the industry by its production designation, 17KS, closely resembled two previous Soviet space stations -- Salyut-6 and Salyut-7 it was a major departure from the latter. Since most of the payload of the future station was expected to be placed onboard "add-on" modules, the core itself was free from a huge science instrument section filling most of the volume inside two previous orbital labs. Available space on Mir's core was used to fit two tiny but comfortable crewmember cabins, each featuring a window!

The Soviet sources reported that number of computers was increased from one aboard Salyut-7 to seven machines on Mir.

The Mir's launch also marked the new approach to the informational policy in space. The launch of the first crew onboard Mir was announced in advance, the first case in the Soviet spaceflight, which did not involve foreign cosmonauts.


The flight version of the core module of the Mir space station during integration with the payload fairing of its Proton-K rocket in Tyuratam.

Two months after the core was launched, Konstantin Feoktistov, the veteran of the Soviet space program gave many hints about the new station's design in the interview to Izvestia. (88) In particular, Feoktistov said that in the future during further deployment of the station, there would be a possibility to employ new systems, which would considerably save onboard propellant. Obviously, he meant onboard gyrodines, which would arrive in the following years onboard Kvant-1 and Kvant-2 modules.

Feoktistov also hinted that the core module could be equipped with additional solar panels and that more effective life-support systems were installed onboard. (Feoktistov apparently referred to the new Elektron oxygen-production system, which breaks down water into hydrogen and oxygen.)

Wet towels, the main personal hygiene method on the previous stations was expected to be replaced with a special sink equipped with a system to pump in and remove water.

Finally, the Soviet sources disclosed that Kosmos-1700 satellite, a.k.a. Luch (Beam), launched ahead of the core module, would be used to relay communications from Mir to the ground control stations. Reportedly, during each orbit the station had a 40-minute window, during which a special antenna installed on the tail section of the core module could "see" the relay sat.


The ASU-8A toilet system was used aboard the Mir space station.

Propulsion system

The integrated propulsion system, ODU, for the core module of the Mir space station and the future service module of the International Space Station consisted of two orbit-correction engines, KD, designated S5.79 with a thrust of 300 kilograms each and 32 small thrusters, DMT, designated 11D428A-10 and developed at NIIMash with a thrust of 12.5 kilograms each and designed to control course, yaw and bank movements of the module. All these engines would be fed from a four tanks with two tanks for oxidizer and two for fuel. Nitrogen gas was used for the pressurization of the tanks.

On November 19, 1985, NIIKhimmash test center started firing and corrosion tests of the 7P17KS EU500 test article of the propulsion system for the core module at 4A bench of IS-104 test facility.

On October 23, 1997, NIIKhimmash started same type of tests on the 8P17KS EU917 article representing the propulsion system of the Zvezda service module. It was conducted at the 4E bench of IS-104 facility. In addition to endurance testing, the prototype was used to confirm the possibility of firing orbit correction engines onboard the Progress cargo ship, while feeding it with propellant from the service module. On Oct. 3, 2012, the 40th engine firing of the Zvezda's propulsion test unit was conducted.


Page author: Anatoly Zak

Last update: March 15, 2024

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The core module of the Mir space station on the drawing board. Credit: Roskosmos

Mir core

A prototype of the Mir core module undergoes testing at NIIKhimmash. Click to enlarge.

The flight version of the core module (17KS) of the Mir space station goes through final checks in Area 2B (MIK-2B) in Baikonur.

A full-scale mockup of the Mir space station used for cosmonaut training in Star City. Module Kvant-1 is on the foreground, the core module is immediately behind. Kvant-2 is on the background. Copyright © 2001 Anatoly Zak

A close-up view of the Mir core module's mockup with a relay antenna. Copyright © 2001 Anatoly Zak

A close-up view of the docking section on the Mir core module docked with the module based on the TKS spacecraft. Copyright © 2001 Anatoly Zak



Stills from a likely footage of the Proton rocket launching the core module of the Mir space station in 1986.


The Proton rocket lifts the core module of the Mir space station into orbit. Credit: RKK Energia