In addition to a new propulsion system and its primary scientific instrument—the BST-1M multispectral telescope—the station had two docking ports, allowing two craft to visit simultaneously.

Short-term visiting crews routinely included international cosmonauts from Warsaw pact countries participating in the Soviet Union's Intercosmos programme.

The station's thermal regulation systems, which made use of a sophisticated arrangement of insulation and radiators, was also derived from that used on Salyut 4.

This procedure allowed resident crews to remain aboard Salyut 6 past the three-month lifespan of the first-generation Soyuz 7K vehicle.

Vladimír Remek of Czechoslovakia, the first space traveller not from the US or USSR, visited Salyut 6 in 1978, and the station hosted cosmonauts from Hungary, Poland, Romania, Cuba, Mongolia, Vietnam, and East Germany.

Salyut 6 introduced a unified propulsion system, with both the engines and the station's control thrusters running on unsymmetrical dimethylhydrazine and nitrogen tetroxide,[3] drawn from a common set of pressurized tanks, allowing the refueling capabilities of the visiting Progress tankers to be exploited to the maximal effect.

The entire engine and fuel storage assembly was contained within an unpressurized bay at the rear of the station, which had the same diameter as the main pressurized compartment.

[1] The main engines could not be fired if the rear docking port was in use, hence any orbital maneuvers during this time had to be performed by the visiting spacecraft.

Salyut 6's propulsion system experienced a serious malfunction during the second crew residency in 1978 and was not usable again for the remainder of the station's lifespan.

This compartment contained two new semi-rigid spacesuits, which allowed much greater flexibility than earlier suits and could be donned within five minutes in an emergency.

Each image was captured simultaneously in six bands in 1200-frame cassettes, which required regular replacement due to the fogging effects of radiation.

Salyut 6 also featured a KATE-140 stereoscopic topographic mapping camera with a focal length of 140 millimetres, which captured images of 450 × 450 kilometers with a resolution of 50 meters in the visible and infrared spectra, which could be operated either remotely or by the resident crews.

Later on during the flight, a Progress spacecraft delivered an external telescope, the KRT-10 [ru] radio observatory, which incorporated a directional antenna and five radiometers.

The antenna was deployed on the rear docking assembly, with the controller remaining inside the station, and was used for both astronomical and meteorological observations.

Then, ground control would command the station itself to rotate 180 degrees, and the Soyuz would close and re-dock at the forward port.