Salyut 5 - Operation

Operation

Four manned missions to Salyut 5 were originally planned. The first, Soyuz 21, was launched from Baikonur on 6 July 1976, and docked at 13:40 UTC the next day. The primary objective of the Soyuz 21 mission aboard Salyut 5 was to conduct military experiments, however scientific research was also conducted, which included studying aquarium fish in microgravity and observing the sun. The crew also conducted a televised conference with school pupils. Cosmonauts Boris Volynov and Vitali Zholobov remained aboard Salyut 5 until 24 August, when they returned to Earth landing 200 km southwest of Kokchetav. The mission had been expected to last longer, however the air within Salyut 5 became contaminated, which affected the crew's psychological and physical condition, necessitating an emergency landing.

On 14 October 1976, Soyuz 23 was launched carrying Vyacheslav Zudov and Valery Rozhdestvensky to the space station. During approach for docking the next day, a faulty sensor incorrectly detected an unexpected lateral motion. The spacecraft's Igla automated docking system fired the spacecraft's manoeuvring thrusters in an attempt to stop the non-existent motion. Although the crew was able to deactivate the Igla system, the spacecraft had expended too much fuel to reattempt the docking under manual control. Soyuz 23 returned to Earth on 16 October without completing its mission objectives.

The last mission to Salyut 5, Soyuz 24, was launched on 7 February 1977. Its crew consisted of cosmonauts Viktor Gorbatko and Yury Glazkov, who conducted repairs aboard the station and vented the air which had been reported to be contaminated. Scientific experiments were conducted, including observation of the sun. The Soyuz 24 crew departed on 25 February. On 26 February the KSI reentry capsule was ejected from the station for recovery.

The fourth planned mission, which would have been designated Soyuz 25 if launched, was intended to visit the station for two weeks in July 1977. It would have been crewed by cosmonauts Anatoly Berezovoy and Mikhail Lisun; the backup crew for the Soyuz 24 mission. The mission was cancelled after higher fuel consumption than expected caused fuel reserves aboard Salyut 5 dropped to a level at which the mission could not have been safely completed. The spacecraft which was constructed for the Soyuz 25 mission was reused for the Soyuz 30 mission to Salyut 6. Since it could not be refuelled, and no longer had the fuel to sustain manned operations, Salyut 5 was deorbited on 8 August 1977, and broke up as it reentered the Earth's atmosphere.