The first Salyut space station

Previous chapter: Development of the Salyut space station


1 Antennas of the rendezvous system 13 Waste collectors
2 Solar panels 14 Attitude control thrusters
3 Telemetry antennas 15 Propellant tanks
4 Windows 16 Toilet
5 Orion celestial telescope 17 Meteoroid sensors
6 Air-regeneration system 18 Treadmill
7 Movie camera 19 Work desk
8 Photo camera 20 Central console
9 Biological research equipment 21 Pressurization tanks
10 Food refrigerator 22 Periscope
11 Sleeping area 23 Soyuz propulsion system
12 Water tanks    

The Salyut space station, identified in the industrial documentation as 17K, structurally consisted of a transfer compartment with a diameter of 2.1 meters, followed by the main work section, in turn containing a science instrument compartment, and closed up with an instrument section.

The work section, borrowed from the Almaz project was subdivided into two cylinders 4.1 and 2.9 meters in diameter, with a conical ring in between. The instrument module (also 2.1 meters in diameter) contained an orbit correction engine, borrowed from the Soyuz spacecraft. Soyuz also became a donor of many critical “internal organs” for its larger counterpart, including the manual and automated flight control system, computing avionics and measuring sensors, the power storage and distribution system, the telemetry, radio and life-support systems. To fit all this heritage hardware into the alien body of Almaz, a whole new structural skeleton had to be designed.

Also, a network of small thrusters responsible for maintaining the attitude of the station in space was developed from scratch, along with a scientific package, which was fitted into a special niche, which was originally intended by Almaz engineers to accommodate a high-power spy camera. Due to the much longer missions planned for Salyut in comparison to Soyuz flights, the station’s thermal control system had to be developed largely anew, with only some hardware recycled from Soyuz.

The station’s scientific instruments with a total mass of 1.5 tons included, the OST-1 Sun-watching telescope, the RT-4 X-ray detector, the ITSK infra-red spectrometer and the OD-4 telescope with 60-power magnification, among other payloads.

The station was expected to accommodate two or three consecutive crews with a total time onboard of around three months. However, its life span was limited by non-replenishable consumable resources, such as propellant and oxygen supplies.

Known specifications of the DOS-7K complex:

DOS-7K complex total mass in orbit 25,600 kilograms
DOS station mass in orbit 18,900 kilograms
7K-T transport spacecraft mass 6,700 kilograms
Payload mass 1,200 kilograms
Full length of the Soyuz/Salyut complex 23 meters
Full length of the Salyut station 14.6 - 16 meters
Maximum body diameters of the Salyut station 4.15 meters
Solar panel span 11 meters
Total solar panel area 42 square meters
Total habitable volume 100 cubic meters
Development cost ~60 million rubles



The article by Anatoly Zak; Last update: August 25, 2021

Page editor: Alain Chabot; Last edit: April 19, 2021

All rights reserved


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Interior view of the DOS-7K space station looking toward the fornt docking port and over the control console.


The flight control console inside the DOS-7K space station.


Flight engineer work site inside the DOS-7K space station.


Propulsion module of the DOS-7K space station.


The Orion telescope