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  • Writer's pictureAeryn Avilla

Diamond in the Rough: The USSR's Military Space Station Almaz

Updated: Jul 9, 2021

The Soviet Union's Almaz, or "Diamond", was a military reconnaissance space station and counterpart to the United States' Manned Orbiting Laboratory program (see Hidden Histories: Manned Orbiting Laboratory). It flew three missions under the civilian program Salyut and supported three crews from 1974 to 1977.

Artist's rendering of Almaz (image source:

Each Almaz originally consisted of three major hardware components. The biggest was the OPS, or Orbital Piloted Station. This was the physical space station itself. Second was the Functional Cargo Block (FGB), which was the resupply craft. Last was the VA spacecraft, which was intended as a launch and return vehicle for the cosmonauts. It was known in the West as the Merkur ("Mercury") and was reusable for up to ten flights. It would have been able to carry a crew of three. Think of the OPS as the International Space Station, the FGB as a Progress or cargo Dragon capsule, and the VA as the Soyuz that takes crews to and from the station.

The Almaz program initially mimicked the American Manned Orbiting Laboratory (MOL). The OPS and VA return capsule would have been mated together atop a UR-500 Proton rocket. Once in orbit, the crew would exit the capsule and enter the space station through a hatch in the heat shield. After anywhere from thirty to sixty days of observation and photography, the crew would reenter the VA, undock from the OPS, and return to Earth. Unlike MOL, which was not meant to be reusable, Almaz was intended to be re-crewed and resupplied. This was to be done using the TKS resupply spacecraft, which consisted of an FGB and a VA launching together on another Proton rocket.

When MOL was cancelled in 1969, Almaz was integrated into the Salyut program. Instead of having one space station stay in orbit with resupply missions carrying crew and cargo, three space stations were to be flown under Salyut designations. Proton rockets would still be used to carry the stations into orbit while the cosmonauts would launch on Soyuz rockets in Soyuz spacecraft. These changes were implemented to make Almaz missions consistent with their partner Salyut missions. This worked out for the better: Soyuz had already been flown and was a reliable vehicle by the time it became part of Almaz while the VA spacecraft still needed to be man-rated. The TKS and VA would never launch together and at the end, the only component of the original mission profile that remained was the OPS.

The feature that made Almaz infamous was not its sketchy purpose but rather its defense mechanism: It was equipped with a 23 millimeter Rikhter rapid-fire cannon that was mounted on the station's underside near the front. The cannon was a modified tail-gun of the Tu-22 bomber. It was on a fixed mounting so the entire station would have to turn to face its target. Salyut 3 was the only vehicle to ever fire it. The firing will be discussed in the mission portion.

The Rikhter space cannon (image source:

Three Almaz space stations were flown from 1973 to 1976. Five crewed Soyuz missions flew to the two successful Almaz stations but only three actually reached them. Only two of those three were considered fully successful at the time. The three crews that had reached their stations racked up 81 days in space.

OPS-1 was designated Salyut 2 and launched on April 3, 1973. A few days after reaching orbit, an accident occurred that left it disabled and depressurized. Despite reaching orbit, Salyut 2 is considered a failure because no crews were ever able to use it.

OPS-2 was designated Salyut 3 and launched on June 25, 1974. The crew of Soyuz 14, Pavel Popovich and Yuri Artyukhin, spent 15 days aboard the station in July. Their capsule's callsign was Berkut, "Golden Eagle", which was also the callsign for Popovich's Vostok 4 spacecraft he flew in 1962. The station came equipped with a shower and both a standing sleeping station and foldaway bed. The floor was covered with Velcro to help the cosmonauts move around. When they were not working, the crew entertained themselves with a magnetic chess set, some books, and a cassette. Additionally, the first water-recycling system was tested on Salyut 3 and was called Priboy. The main objectives were Earth observation and military reconnaissance so the majority of the work done onboard was with the Agat-1 telescope. It is said to have had an optical resolution of three to one meters. The cosmonauts observed targets set out on the ground at Baikonur using a wide-film camera primarily used for the military reconnaissance. Other objectives included study of water pollution, agricultural land, and oceanic ice formation. While on station, the cosmonauts were able to develop film. Critical images were printed and then scanned by a TV imaging system back to Earth and those of less importance were loaded into a capsule and sent back to the ground. Most time during the mission was taken up by secret military activities. The crew departed from the Almaz on July 19 and left behind enough supplies for the next crew to last at least six months. Soyuz 15 was follow in August but was unable to dock due to malfunctioning in the Igla docking system of the Soyuz. They returned to Earth two days later. With the station abandoned, the cannon could be remotely tested. It was deemed safer to fire with no crew onboard due to concerns over excessive vibration and noise within the station. It was a success and the Almaz became the first and only armed, crewed military spacecraft ever flown (at least, that we know of). It deorbited in January 1975.

The crew of Soyuz 14, Yuri Artyukhin and Pavel Popovich (

OPS-3 was designated Salyut 5 and launched on June 22, 1976. Its first crew was Soyuz 21 with Boris Volynov and Vitali Zholobov in July. Along with military experiments, aquarium fish were studied in microgravity. Like American astronauts have been doing since the Space Shuttle program, the crew also televised a conference with school students. The crew stayed onboard Almaz until August 24 though the mission was expected to last longer. A fuel leak caused the spacecraft to smell like nitric acid, which affected the cosmonaut's psychological and physical conditions. On October 15, Soyuz 23 with Vyacheslav Zudov and Valery Rozhdestvensky attempted to dock with Salyut 5 but were unable to as a result of a malfunction in the Soyuz's automatic docking system. The crew was able to deactivate the Igla but docking under manual control used too much fuel so the crew returned to Earth the next day. A third mission, Soyuz 24 with Viktor Gorbatko and Yury Glazkov, launched in February 1977 and repaired the fuel leak. They returned to Earth on the 25th because the Almaz was starting to run low on propellant for its main engines and attitude control system. The fourth mission would have been Soyuz 25 but it was cancelled as a result of the propellant shortage.

The crew of Soyuz 21, Boris Volynov and Vitali Zholobov (

Seven more Almaz spaceframes were constructed up until program cancellation. Two flew as uncrewed radar-carrying reconnaissance satellites. Two others, Almaz-205 and Almaz-206, are currently owned by Excalibur Almaz, a private company planning to launch them as crewed space stations. OPS-4 was allegedly supposed to have a Shchit-2 space-to-space cannon, reported to be a two projectile system. However, no photographs of it have ever been published and there is little to prove it was even installed on the station. After Salyut 5, the Soviet Ministry of Defense determined that unmanned reconnaissance satellites were more efficient and much cheaper than manned ones.

Even today, space stations can trace their lineage back to the original Almaz OPS hull. These are called DOS space station core modules and were used for the regular civilian Salyut. DOS-1 formed the basis for Salyut 1, the first space station in history. DOS-7 served as the Mir Core Module for the Mir space station, the successor to Salyut and predecessor to the International Space Station. DOS-8 is known as Zvezda and was the third module of the ISS ever put into orbit.

Zvezda taken from the crew of STS-97 (Public Domain image)

Almaz still remains the only manned military space station. The Salyut program continued until Salyut 6 in 1981. Its American counterpart, Skylab, flew three missions from 1973 to 1974. The Apollo-Soyuz Test Project in July 1975 ushered in the end of the Space Race and partially thawed the Cold War, diminishing the need for crewed military space stations.

Author's note: Thanks for reading and remember to like and share this post!



  • Becker, Joachim. “Salyut 3 Expedition 1.” Salyut 3: Expedition 1,

  • Becker, Joachim. “Salyut 5 Expedition 1.” Salyut 5: Expedition 1,

  • Grahn, Sven. “The Almaz Space Station Program.” Almaz Space Stations,

  • Wade, Mark. Almaz,


Artist's rendering of Salyut 2:

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