2.5.3 Salyut 4 Career
Entries below describe Salyut 4 operations during Soyuz missions to the station. For more information on the Soyuz missions, see sections 1.8.4.3 and 1.10.4.1 Dates are hard dock to undock; if no hard dock achieved, launch to landing.
| Soyuz 17 | January 12-February 9, 1975 | |
| Alexei Gubarev, Georgi Grechko Crew code name—Zenit When Soyuz 17 docked, Salyut 4 was in an unusually high circular orbit at 350 km. Astrophysics was a major component of their mission (hence the high altitude). The Zenits discovered that the main mirror of the solar telescope had been ruined by direct exposure to sunlight when the pointing system failed. They resurfaced the mirror and worked out a way of pointing the telescope using a stethoscope, stopwatch, and the noises the moving mirror made in its casing.[1] | ||
| “The April 5 Anomaly” | April 5, 1975 | |
| Vasili Lazerev, Oleg Makarov Crew code name—Ural Failed to dock with Salyut 4 due to a catastrophic Soyuz booster failure during ascent to orbit. | ||
| Soyuz 18 | May 26-July 26, 1975 | |
| Pyotr Klimuk, Vitali Sevastyanov Crew code name—Kavkaz The Kavkaz crew carried out 90 scientific and engineering experiments, continuing the work of the Soyuz 17 crew. During their stay, they conducted two communications sessions with the ASTP Soyuz (Soyuz 19) crew. | ||
| Soyuz 20 | November 17, 1975-February 16, 1976 | |
| First spacecraft to dock unmanned with a Salyut station. Carried life sciences experiments, qualified Soyuz for long-duration flights attached to a station, and served as proof-of-concept mission for Progress development. | ||
- ↑ Sheldon, pp. 208, 210.
