The fourth planned mission, Soyuz 25, was intended to visit the station in July 1977, however it was cancelled after fuel reserves aboard Salyut 5 dropped to a level at which the mission could not have been safely completed.
The fourth planned mission, Soyuz 25, was intended to visit the station in July 1977. It would have been crewed by cosmonauts Anatoly Berezovoy and Vladimir Kozelsky, however it was cancelled after fuel reserves aboard Salyut 5 dropped to a level at which the mission could not have been safely completed.