Salyut 6 Credit - © Mark Wade

The Salyut 6 space station was the most successful of the DOS series prior to Mir. It was aloft for four years and ten months, completing 27,785 orbits of the earth. Five main expeditions and 11 short duration expeditions visited the station, of which nine had international crews. A total of 676 days of piloted operations were conducted by 27 cosmonauts with steadily increasing flight duration: 18, 75, 96, 140, and 185 days. 35 automatic dockings were conducted with the station by 20 Soyuz, 12 Progress, and 1 TKS spacecraft.

Autopilot: Digital. Propulsion/RCS Systems: Unitary. Main propulsion 2 x 300 kgf, stabilization and orientation motors 32 x 24 kgf. Telemetry: High Rate. Rendezvous/Docking: Kurs. Equipment: - MKF-6 multispectral camera system - KT-140 high resolution topographical camera system (200,000 sq. km. per film frame) KRT-10 10 m diameter radio telescope - Splav alloying/materials processing furnace - Kristal containerless processor for semiconductor materials - BST-1M 1.5 m diameter cryogenic submillimeter/ ultraviolet/infrared telescope Refraktion and Zarya spectrometers for sun/moon views through earth's limb - Ispartitel experiment for coating of plates with materials - Yelena gamma ray telescope - Oasis plant growth unit - Polinom cardiovascular monitoring system.

Design Life: 1765 days. Typical orbit: 212 km circular orbit, 51.5 deg inclination. Length: 14.40 m (47.20 ft). Maximum Diameter: 4.15 m (13.61 ft). Span: 17.00 m (55.00 ft). Habitable Volume: 90.00 m3. Mass: 19,824 kg (43,704 lb). Payload: 1,500 kg (3,300 lb). RCS Coarse No x Thrust: 14 X 98 N. RCS Fine No x Thrust: 18 x 10 N. Main Engine: KRD-79. Main Engine Thrust: 5.880 kN (1,322 lbf). Main Engine Propellants: N2O4/UDMH. Main Engine Propellants: 1,200 kg (2,600 lb). Main Engine Isp: 305 sec. Electrical System: Solar Panel Span: 17.0 m, area: 60 sq. m. Electric System: 2.00 average kW.

• 1977 September 29 - Salyut 6 - Program: Salyut 6. Launch Site: Baikonur. Launch Complex: LC81/24. Launch Vehicle: Proton. Mass: 19,824 kg (43,704 lb). Perigee: 188 km (116 mi). Apogee: 237 km (147 mi). Inclination: 51.60 deg. Period: 88.70 min. Duration: 1,763.71 days.
  Conduct of scientific and technical research and experiments; further testing of station design, on-board system and equipment. Soyuz 25 docking unsuccessful. EVA 20 Dec 1977 to examine forward docking port (no damage). EVA 29 July 1978 to retrieve externally mounted experiments (micrometeorites, biopolymers, radiation plates, materials tests). Soyuz 33 failure to dock due to propulsion failure April 1979. Soyuz 34 launched unmanned to provide replacement vehicle June 1979. EVA August 15 to dislodge 10 m diameter KRT-10 radio telescope from aft docking collar. Repair mission Soyuz T-3 December 1980 (temperature control hydraulics). Repair mission Soyuz T-4 March 1981 (stuck solar array). Salyut ejected a module on May 31 (perhaps retained Soyuz Orbital Module). Kosmos 1267 docks 19 June 1981. Commanded to reentry using Kosmos 1267 propulsion system over Pacific July 29 1982. Additional Details: Salyut 6.

• 1977 December 19 - EVA Salyut 6 EO-1-1 - Program: Salyut 6. Crew: Grechko, Romanenko. Flight: Salyut 6 EO-1.
  Inspected Salyut 6 docking port.

• 1978 July 29 - EVA Salyut 6 EO-2-1 - Program: Salyut 6. Crew: Ivanchenkov, Kovalyonok. Flight: Salyut 6 EO-2.
  Retrieved material samples and equipment.

• 1979 August 15 - EVA Salyut 6 EO-3-1 - Program: Salyut 6. Crew: Lyakhov, Ryumin. Flight: Salyut 6 EO-3.
  Jettisoned KRT-10 antenna from rear docking port.

• 1982 July 29 - Burnup of Salyut 6 Space Station (USSR) -