Three crewed military reconnaissance stations were launched between 1973 and 1976: Salyut 2, Salyut 3 and Salyut 5. To cover the military nature of the program the three launched Almaz stations were designated as civilian Salyut space stations. Salyut 2 failed shortly after achieving orbit, but Salyut 3 and Salyut 5 both conducted successful crewed testing. Following Salyut 5, the Soviet Ministry of Defence judged in 1978 that the time and resources consumed by station maintenance outweighed the benefits relative to automatic reconnaissance satellites.

The space stations cores were known internally as OPS (Russian: ОПС, GRAU index 11F71 and 11F71B), from “Orbital Piloted Station” (Russian: Орбитальная Пилотируемая Станция). As part of the Almaz program, the Soviets developed several spacecraft for support roles—the VA spacecraft, the Functional Cargo Block and the TKS spacecraft—which they planned to use in several combinations. The heritage of the Almaz program continues, with the ISS module Zarya being one example.

The Almaz space station programme involved three major hardware components:

• Orbital Piloted Station (OPS, 11F71) module, forming the space station itself,
• Functional Cargo Block (FGB, 11F77), intended as resupply craft for the stations, and
• VA spacecraft (11F74, known in the West as the Merkur spacecraft), intended as launch and return vehicle for the crews, and reusable for up to 10 flights.

The OPS would have a maximum diameter of 4.15 metres (13.6 ft), a mass of roughly 20 tonnes (20 long tons; 22 short tons), and an internal habitable volume of 47.5 cubic metres (1,680 cu ft).

Much like its MOL/Gemini counterpart, the initial Almaz APOS space station design called for the launch of an Almaz-OPS space station and a VA return capsule containing its initial three man crew, mated together as OPS/VA atop Chelomei’s UR-500 Proton rocket. As with MOL/Gemini, once in orbit the crew would access the lab through a hatch in the heat shield at the bottom of the VA capsule. After an extended stay of 30 to 60 days of military observation and photography the crew would return to Earth by way of a VA return vehicle.

Unlike the American MOL design, the Soviets designed the Almaz to be recrewed and resupplied. For this, they created the TKS resupply craft (11F72), which consisted of an FGB and a VA return craft to carry the crew, also launched together on a Proton rocket. At the station, one docking port would be available to receive the TKS craft once the previous crew had left the station in their VA capsule.

While the MOL was cancelled in 1969, the Almaz program was integrated into the Salyut programme and resulted in three flown space stations, two of which were crewed successfully. As “man-rating” the VA spacecraft and the Proton rocket took longer, the first phase called for the launch of three Almaz stations without the VA spacecraft, with the crew instead launched separately by Soyuz rocket in a modified Soyuz spacecraft. Plans called for the first three Almaz stations to be visited by three two-month-long expeditions each. This was realized fully by two missions and partially by one; however, the initial intention of launching Almaz APOS and the TKS spacecraft together with its crew in VA spacecraft would never materialize during the program, and neither would the TKS craft play its intended role as resupply craft. The Almaz APOS design, without VA spacecraft, would evolve into the Almaz OPS station cores of the Salyut programme.

Defense measures

In addition to reconnaissance equipment, Almaz was equipped with a unique 23mm Rikhter (factory index 261P or 225P) rapid-fire cannon mounted on the forward belly of the station. This revolver cannon was modified from the tail-gun of the Tu-22 bomber and was capable of a theoretical rate of fire of 1800-2000 (up to 2600) rounds per minute. Each 168 gram (ammo 23-OFZ-D-R ) or 173 gram (ammo 23-OFZ-G-R) projectile flew at a speed of 850 m/s relative to the station. The cannon was tested at the end of the mission by firing 20 rounds, when the station was operating in uncrewed mode. To aim the cannon, which was on a fixed mounting, the entire station would be turned to face the threat. The Almaz series are the only known armed, crewed military spacecraft ever flown.

Salyut 3/OPS-2 conducted a successful remote test firing with the station uncrewed due to concerns over excessive vibration and noise.

OPS-4 was to have featured two rockets instead of the aircraft cannon, but this system has not been shown publicly and may have never been fully manufactured despite it being used experimentally.

Orbital Piloted Stations (OPS)

Three Almaz OPS space stations were flown from 1973 to 1976 in the Salyut programme: Salyut 2 (OPS-1), Salyut 3 (OPS-2) and Salyut 5 (OPS-3). Five crewed Soyuz expeditions were flown to the Almaz space stations Salyut 3 and Salyut 5, with three reaching their stations and only two of the missions being considered fully successful at that time – the three crews that had reached their stations had crewed Almaz stations for a total of 81 days when the program was ended.

Besides the three flown space stations OPS-1 to OPS-3, seven more spaceframes of Almaz space stations had been built when the program was cancelled: OPS-4, Almaz-205, Almaz-206, Almaz-T, Almaz-T2 (Kosmos 1870), Almaz-1 and Almaz-2 – with Almaz-T2 and Almaz-1 having successfully flown as repurposed uncrewed radar-carrying reconnaissance satellites. The partially outfitted hulls of Almaz-205 and Almaz-206 are today in the property of Excalibur Almaz, a company that plans to launch these as crewed space stations.

Almaz-T (uncrewed)

Following cancellation of the program, the Almaz station was reconfigured as an uncrewed heavy radar-carrying reconnaissance satellite. Three such satellites were launched, two of which functioned successfully in orbit.

Header: Almaz space station at VDNKh (Russia)