The Soviet Union launched Salyut 1, the world’s first space station, to test long-term living and research in orbit. It set the basic idea of a station as a laboratory that crews could visit by docking spacecraft.
Soyuz 11 successfully docked with Salyut 1 and the crew lived and worked aboard the station for about 23 days. This proved that people could operate a space station for weeks at a time, not just days.
After leaving Salyut 1, the Soyuz 11 capsule depressurized on the way back to Earth, killing all three cosmonauts. The disaster forced changes in Soyuz procedures and spacecraft design, including renewed emphasis on crew safety measures such as pressure suits.
Salyut 2, an Almaz-derived military station flown under the Salyut name, reached orbit but quickly became unusable after losing control and depressurizing. The failure showed how hard it was to operate early stations and pushed improvements in later designs and operations.
Another Salyut-type station (DOS-3) suffered control-system problems and burned up after only days in space. The Soviet Union publicly labeled it “Kosmos 557,” reflecting the program’s mix of secrecy and rapid iteration while engineers worked to make stations more reliable.
Salyut 3 (also known as Almaz OPS-2) was launched as a military reconnaissance station but presented publicly as part of the Salyut series. It demonstrated that the Soviet station program could support both civilian research goals and military objectives.
Salyut 4 (DOS-4) continued the civilian line of stations with improved reliability and scientific capability. It supported repeated crew visits and longer stays, building operational experience for routine station life.
Salyut 5 (Almaz OPS-3) was the final Almaz military station launched under the Salyut label. It marked the wind-down of the Almaz station effort as the Soviet program moved toward more capable, longer-lived civilian stations.
Salyut 6 launched with two docking ports, allowing a crew vehicle and a second spacecraft to be attached at the same time. This change enabled regular resupply, visiting crews, and swapping Soyuz spacecraft—key steps toward continuous, long-duration station operations.
Soyuz 26 delivered the first long-duration crew to Salyut 6, beginning a new phase of more routine station occupation. The mission helped establish practices like crew rotations and longer work schedules needed for extended stays in orbit.
Progress 1 docked with Salyut 6 as the first Progress cargo ship to supply a space station. Automated resupply and refueling made it practical to keep stations operating longer and reduced dependence on crewed flights for basic logistics.
Soyuz 28 visited Salyut 6 with a Soviet cosmonaut and a guest cosmonaut from Czechoslovakia, part of the Intercosmos program. These flights expanded station work to international crews, adding diplomatic goals to the technical program.
Salyut 7 was launched as the next major station after Salyut 6, continuing the two-docking-port approach and supporting longer missions. It also served as a testbed for more complex station operations that would later be used on Mir.
The first resident crew arrived on Salyut 7, starting a series of long-duration expeditions. This period strengthened the Soviet ability to run a station as a working laboratory for months, including life science, Earth observation, and technology tests.
After Salyut 7 lost power and communications, Soyuz T-13 carried cosmonauts who manually docked and worked to bring the station back to life. The mission showed that major in-orbit repairs were possible, extending station usefulness even after severe failures.
Soyuz T-15 docked with both Mir and Salyut 7 in one mission, transferring equipment and completing remaining work on the older station. This was the last time a crew visited Salyut 7, effectively closing the active, crewed phase of the Salyut station program.
Salyut space station program: construction, crews, and experiments (1971–1986)