Salyut 3 (, also known as OPS-2 or Almaz 2) was <!--These tags are used to exclude unnecessary text from the excerpt at Salyut programme.--><noinclude>a Soviet space station </noinclude>launched on 25 June 1974. It was the second Almaz military space station, and the first such station to be launched successfully. Due to the military nature of the station, the Soviet Union was reluctant to release information about its design, and about the missions relating to the station.
It attained an altitude of 219 to 270 km on launch and NASA reported its final orbital altitude was 268 to 272 km. Only one of the three intended crews successfully boarded and operated the station, brought by Soyuz 14. Soyuz 15 attempted to bring a second crew but failed to dock, after which the third planned mission to the station was cancelled.
Although little official information has been released about the station, several sources report that it contained multiple Earth-observation cameras, as well as an on-board gun. The station was deorbited and re-entered the atmosphere on 24 January 1975. The next space station launched by the Soviet Union was the civilian station Salyut 4; the next military station was Salyut 5, which was the final Almaz space station.
Background
The first space station, Salyut 1 (also known as DOS-1), was launched by the Soviet Union in April 1971. Only one mission successfully docked with Salyut 1, this was Soyuz 11. Its three-person crew spent 22 days aboard the station in June 1971. Tragically, the crew was killed just before reentry when an airlock opened prematurely, after undocking from the station.
At the time, the Soviet Union had competing "civilian" and military space programs. Salyut 1, was developed under the civilian program. NASA historian Siddiqi has speculated that given the size of the telescope's mirror, it likely had a resolution better than . The telescope was used in conjunction with a wide-film camera and primarily for military reconnaissance. The cosmonauts are said to have observed targets set out on the ground at Baikonur. Secondary objectives included the study of water pollution, agricultural land, possible ore-bearing landforms, and oceanic ice formation.
The cosmonauts were able to develop film while on the station. Important or interesting images were printed and then scanned by a TV imaging system for broadcast to Earth. Later Russian sources indicate that the gun was the virtually unknown (in the West) Rikhter R-23. These claims have reportedly been verified by Pavel Popovich, who had visited the station in orbit, as commander of Soyuz 14. The crew of Soyuz 14 consisted of commander Pavel Popovich and flight engineer Yury Artyukhin. The crew spent 15 days aboard the station.
On 9 July, it was reported that the crew activated the Earth-observation cameras, and spent several days taking photos of various locations, including central Asia. Due to the limited battery life of their Soyuz spacecraft, they de-orbited and landed two days after launch. This record was broken the following year, with Deke Slayton's spaceflight as a part of the Apollo–Soyuz Test Project.
Also following the decision to not send any more cosmonauts to the station, the on-board gun was commanded by the ground to be fired; some sources say it was fired to depletion,