The next crew, including V. Lazarev and O. Makarov, was launched toward Salyut 4 on April 5, 1975. Problems quickly arose. The ordeal started during an abnormal separation between the second and the third stages of the launcher, causing the spacecraft to spin uncontrollably. Fortunately, the crew was able to perform an emergency landing in the Altai mountains, but not until the cosmonauts experienced a force of around 21 Gs, or 21 times the usual force of gravity on Earth. Usually, astronauts of this era endured no more than 5 Gs during a launch or re-entry.

On May 25, 1975, a new crew was launched toward Salyut 4 and spent 63 days onboard. In November 1975, an unmanned Soyuz 20 docked to Salyut 4 automatically and stayed docked to the station for three months, demonstrating the future potential of the orbital system.

The highly successful Salyut 4 was deorbited only on February 3, 1977, bringing the highest civilian honor -- "Hero of the Socialist Labor" -- to the chief designer of the spacecraft, Yuri Semenov, and one of the assembly technicians, V. Morozov. This happened despite official objections that Morozov was not a member of the Communist Party.