Salyut 4

Salyut 4 (DOS-4)
Salyut 4 being constructed
The insignia of the Salyut Program.
Station statistics
COSPAR ID1974-104A
SATCAT no.07591Edit this on Wikidata
Call signSalyut 4
LaunchDecember 26, 1974
04:15:00 UTC
Launch padLC-81/24, Baikonur Cosmodrome, Soviet Union
ReentryFebruary 3, 1977
  • 18,210 kilograms (40,150 lb) (fuelled mass)
  • 16,210 kilograms (35,740 lb)
Length15.8 m
Width4.15 m
Pressurised volume90 m3
Periapsis altitude136 mi (219 km)
Apoapsis altitude168 mi (270 km)
Orbital inclination51.6 degrees
Orbital period89.1 minutes
Days in orbit770 days
Days occupied92 days
No. of orbits12,444
Distance travelled~313,651,190 mi
(~504,772,660 km)
Statistics as of de-orbit and reentry
Salyut 4 and Soyuz diagram

Salyut 4 (DOS 4) (Russian: Салют-4; English translation: Salute 4) was a Salyut space station launched on December 26, 1974 into an orbit with an apogee of 355 km, a perigee of 343 km and an orbital inclination of 51.6 degrees. It was essentially a copy of the DOS 3 (or Kosmos 557), and unlike its ill-fated sibling it was a complete success. Three crews attempted to make stays aboard Salyut 4 (Soyuz 17 and Soyuz 18 docked; Soyuz 18a suffered a launch abort). The second stay was for 63 days duration, and an unmanned capsule, called Soyuz 20, remained docked to the station for three months, proving the system's long-term durability despite some deterioration of the environmental system during Soyuz 18's mission. Salyut 4 was deorbited February 2, 1977, and re-entered the Earth's atmosphere on February 3.