"Salyut-4" marked a significant milestone as the first domestic station where two crews successfully worked. Launched on December 26, 1974, its mission included the historic docking of "Soyuz-19" and "Apollo," which further enhanced its importance in space exploration history.

The Long-Term Orbital Stations project saw notable progress with the development of "Salyut-4." Setting it apart from its predecessors, this station demonstrated advancements in space technology and capabilities, paving the way for further innovations in scientific research and international cooperation in space missions.