It attained an altitude of 219 to 270 km on launch and its final orbital altitude was 268 to 272 km. Salyut 3 had a total mass of about 18 to 19 tons. It had two solar panels laterally mounted on the center of the station and a detachable recovery module for the return of research data and materials. Only one of the three intended crews successfully boarded and manned the station, brought by Soyuz 14; Soyuz 15 attempted to bring a second crew but failed to dock. Nevertheless, it was an overall success. The station's orbit decayed, and it re-entered the atmosphere on January 24, 1975.
Salyut 3 was the first space station to maintain constant orientation relative to the Earth surface. To achieve that, as many as 500,000 firings of the attitude control thrusters had been performed.
It tested a wide variety of reconnaissance sensors. On September 23, 1974, the station's recovery module was released and re-entered, being recovered by the Soviets.
Some sources claim that on January 24, 1975 (after the station was ordered to deorbit) trials of the on-board 23 mm Nudelmann aircraft cannon (other sources say it was a Nudelmann NR-30 30 mm gun) were conducted with positive results at ranges from 500 m to 3000 m.
Cosmonauts had confirmed that a target satellite was destroyed in the test.
Firings were conducted in the direction opposite to the station's velocity vector, in order to shorten the "orbital life" of the cannon's shells. A total of three firings were conducted during the flight of the Salyut 3.
Agat-1 photo-camera, with a focal length of 6,375 millimeters and a resolution better than 3 meters.
OD-5 optical visor,
POU panoramic device
Volga infrared camera with a resolution of 100 meters
Pingvin exercise suit
Priboy water regeneration system
Length - 14.55 m
Maximum diameter - 4.15 m
Habitable volume - 90 m³
Weight at launch - 18,900 kg
Launch vehicle - Proton (three-stage)
Number of solar arrays - 2
Resupply carriers - Soyuz Ferry
Number of docking ports - 1
Total manned missions - 2
Total long-duration manned missions - 1
Number of main engines - 2
Main engine thrust (each) - 400 kgf (3.9 kN)