On April 19, 1971, the Proton launch vehicle successfully launched the world's first long-term orbital station (DOS) Salyut into orbit.

In contrast to the previously launched manned orbital stations, Salyut had an airlock for docking of a cargo spacecraft, which made it possible for it to operate autonomously in orbit for a long period of time.

“The launch of the first long-term orbital station opened a fundamentally new stage in the exploration and exploration of outer space by humans.

DOS-1 was a new type of spacecraft that automatically and with the participation of a person to solve a variety of scientific and applied problems in conditions of a long flight, "- says the website of the state corporation" Roscosmos ".

The ministry notes that "orbital stations with interchangeable crews made it possible for people to work continuously in outer space, made it possible to study the effect of space and weightlessness on the human body, to conduct astrophysical research, as well as to study the surface and atmosphere of the Earth." 

Habitable space

Station "Salyut", which in the documents was also designated as "Product 17K" or No. 121, was developed at the Central Design Bureau for Experimental Mechanical Engineering (TsKBEM, now NPO Energia).

Work on its creation began at the end of 1969.

The project was supervised by chief designer Vasily Mishin.

  • Salyut-7 with the docked Soyuz spacecraft

  • NASA

The Salyut's mass was 18.6 tons. It was intended to operate in low-earth orbit at an altitude of 200-300 km.

The duration of the flight of the station was limited by the life support system and the onboard fuel supply and was 175 days.

The orbital station consisted of three compartments: transition and working (both sealed), and a leaky aggregate.

Five days after the launch and insertion of Salyut into orbit, the Soyuz-10 spacecraft with the first crew was sent to the station. On board the ship were Commander Vladimir Shatalov, Flight Engineer Alexei Eliseev and Test Engineer Nikolai Rukavishnikov. The crew successfully docked with the station, but they failed to get to the Salyut - a malfunction of the docking station on the Soyuz prevented it. As a result, 5 hours and 30 minutes after docking, the spacecraft was forced to undock. On April 25, three cosmonauts returned safely to Earth.

On June 6, 1971, the USSR sent a second crew aboard the Soyuz-11 spacecraft to Salyut.

This time the docking took place normally and the cosmonauts Georgy Dobrovolsky, Vladislav Volkov and Viktor Patsaev on June 7, 1971 moved from the docked spacecraft to the station.

Thus, they became the first ever crew of a long-term orbital station.

  • The crew of the Soyuz-11 spacecraft with chief designer V.P.

    Mishin before the flight

  • © salyut.gmik.ru

In total, Dobrovolsky's team spent about 23 days in orbit.

During this time, they managed to carry out mapping of the starry sky using the Orion ultraviolet telescope, study the waters of the World Ocean in the interests of fisheries, and carry out a large program of medical experiments.

Having fully completed the flight program, the crew undocked from the station and headed for Earth.

However, they were not destined to return home - an accident occurred during the descent.

Due to the depressurization of the descent vehicle, three cosmonauts died.

After clarifying the cause of the tragedy, the State Commission decided to temporarily suspend flights and modify the Soyuz spacecraft.

The station continued to operate in orbit in unmanned mode.

 On October 11, 1971, on command from the Earth, the engine was turned on on "Salyut", after which the station entered the dense layers of the atmosphere and ceased to exist.

After that, the Soviet Union continued to develop the program for creating orbital stations.

Within the framework of this program, the development was carried out in two directions: civil (DOS) and military (a series of stations "Almaz", which were still officially called "Salutes").

The first was carried out by TsKBEM, and the second - by the Central Design Bureau of Mechanical Engineering (now - JSC VPK NPO Mashinostroyenia).

According to experts, the work was not easy - Soviet designers created a completely new direction in science and industry, so numerous difficulties and mistakes in this matter were inevitable.

So, the launch of DOS-2 in 1972 failed due to the accident of the launch vehicle.

The DOS-3 station entered orbit in November 1973, but due to equipment malfunctions it became unusable, for some time performed a passive flight, and later, when trying to change the altitude of the orbit, it entered the atmosphere and ceased to exist.

Due to unsuccessful launches, these stations did not formally receive a serial number within the framework of the Salyut program.

The launch in April 1973 of the Salyut-2, which was developed under the Almaz program, turned out to be more successful.

However, this time too, an abnormal situation occurred: the station was depressurized, due to which it spent only 54 days in orbit.

Crews did not go to her.

Many errors were corrected during the creation of the Salyut-3 station.

It was launched into orbit on June 25, 1974 and spent 213 days in space.

A crew consisting of commander Pavel Popovich and flight engineer Yuri Artyukhin was sent to Salyut-3.

After the events of 1971, it was decided to fly only in spacesuits, so the crew was reduced to two people.

Artyukhin and Popovich spent 15 days at the station and successfully returned to Earth.

The Salyut-3 station was created as part of the Almaz military program, therefore, for experimental purposes, a 23-mm automatic cannon was installed on it, created on the basis of the NR-23 aircraft cannon. 

Subsequent launches of the Salyut-4, Salyut-5, Salyut-6 and Salyut-7 stations took place without incident.

With each new launch, the time spent by the apparatus in orbit and the duration of the work of the crews increased.

  • Station "Mir"

  • NASA

A breakthrough is considered the launch of Salyut-8, which became the basis for the world's first multi-module orbital complex Mir.

In total, the station spent 5510 days in orbit. 

And Salyut-9, which was originally planned as the basis for the Russian orbital complex Mir-2, eventually became part of the Russian segment of the International Space Station (ISS) in the form of the Zvezda life support module.

In this capacity, the station is still operating in orbit. 

"An extremely difficult task"

According to Nathan Eismont, a researcher at the Space Research Institute of the Russian Academy of Sciences, the program for creating long-term orbital stations has become a breakthrough in space exploration.

"Station" Salut "has opened up new opportunities.

Thanks to this project, astronauts could subsequently spend more time in space and solve a wide range of tasks.

It was this platform that served as the basis for the implementation of the Mir project, thanks to which serious results were obtained, including in the course of various medical experiments, "the analyst said in an interview with RT.

In turn, military expert Yuri Knutov noted that during the development of the Salyut project, Soviet engineers managed to solve many complex technical problems.

“To create a station, place it in orbit and make it habitable is an extremely difficult task.

For example, it was necessary to create a life support system that could make the station fit for life for a long time.

It was necessary to develop a system for the rehabilitation of astronauts, which would allow them to restore their health.

The issues of going into space, repairing the orbital station were mastered.

All this was done for the first time in history by our scientists, "the expert emphasized in a conversation with RT.

According to Knutov, the creation of "Salutes" was also important from the point of view of ensuring the defense of the USSR.

“The Almaz military stations had unique technologies, including the possibility of optical control over military and civilian objects.

These orbital stations played a crucial role in ensuring the country's defense capability, ”Knutov said.

  • SM "Zvezda" with the docked spacecraft "Progress"

  • NASA

All these achievements allowed the subsequent creation of the Mir orbital station, and then the ISS, he added.

"The USSR made amazing developments that will be in demand in the future and will serve as the basis for the creation of a new orbital station," the analyst said.

Experts agreed that regardless of the fate of the ISS, whose operational life is coming to an end, Russia should continue to develop the program for creating orbital stations.

“Without the intense, everyday work that is now being carried out on the ISS, one cannot count on the successful conduct of any space exploration expeditions in the future.

Without such stations, without the experience gained in the course of their work, humanity will not achieve a new breakthrough in this area, ”concluded Nathan Eismont.