Salyut 3 Salyut 3 ( ; ; also known as OPS - 2 or Almaz 2 ) was a Soviet space station launched on June 25 , 1974 . It was the second Almaz military space station , and the first such station to be launched successfully . It was included in the Salyut program to disguise its true military nature . 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 manned the station , brought by Soyuz 14 ; Soyuz 15 attempted to bring a second crew but failed to dock . 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 January 24 , 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 called " DOS - 1 " ) had been launched by the Soviet Union in April 1971 . Only one mission successfully docked with Salyut 1 , which was Soyuz 11 , whose three person crew stayed aboard the station for 22 days in June 1971 . After undocking from the station , the Soyuz 11 crew were killed during atmospheric reentry . At the time there were competing civilian and military Soviet space programs ; Salyut 1 , for example , was developed as a civilian program . Other civilian stations , called Durable Orbital Stations ( DOS ) , were considered successors of Salyut 1 . These consisted of the unsuccessful DOS - 2 in 1972 , DOS - 3 in 1974 , and later the successful Salyut 4 , Salyut 6 , and Salyut 7 . The space stations funded and developed by the military , known as " Almaz " stations , were roughly similar in size and shape to the civilian DOS stations . But the details of their design , which is attributed to Vladimir Chelomey , are considered to be significantly different from the DOS stations . The first Almaz station was Salyut 2 , which launched in April 1973 , but failed only days after reaching orbit , and hence it was never manned . Description . Salyut 3 consisted of an airlock chamber , a large - diameter work compartment , and a small diameter living compartment , giving a total habitable volume of 90 m³ . It had two solar arrays , one docking port , and two main engines , each of which could produce 400 kgf ( 3 . 9 kN ) of thrust . Its launch mass was 18 , 900 kg . The station came equipped with a shower , a standing sleeping station , as well as a foldaway bed . The floor was covered with Velcro to assist the cosmonauts moving around the station . Some entertainment on the station included a magnet ic chess set , a small library , and a cassette deck with some audio cassette tapes . Exercise equipment included a treadmill and Pingvin exercise suit . The first water - recycling facilities were tested on the station ; the system was called Priboy . Earth - observation cameras . The work compartment was dominated by the " Agat - 1 " Earth - observation telescope , which had a focal length of 6 . 375 metres and an optical resolution better than three meters , according to post - Soviet sources ; NASA historian Siddiqi has speculated that given the size of the telescope ' s mirror , it likely had a resolution better than one metre . The telescope was used in conjunction with a wide - film camera , and was used primarily for military reconnaissance purposes . The cosmonauts are said to have observed targets set out on the ground at Baikonur . Secondary objectives included 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 . They needed as little as 30 minutes to shoot , develop , and scan a photograph . Less important images were packed into a small Earth - return capsule , which could be ejected from the station . In addition to the Agat - 1 camera , other cameras on board included a topographical camera , a star camera , and Volga infrared camera with a resolution of 100 meters . Cosmonaut Pavel Popovich , who visited the station as Commander of Soyuz 14 , recalled that the station was equipped with 14 cameras . On - board gun . The Salyut 3 station was equipped with a " self - defence " gun , which had been designed for use aboard the station , and whose design is attributed to Nudelman . Some accounts claim the station was equipped with a Nudelman - Rikhter " Vulkan " gun , which was a variant of the 23 mm Nudelmann aircraft cannon , or possibly a Nudelmann NR - 30 30 mm gun . 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 . Due to potential shaking of the station , in - orbit tests of the weapon with cosmonauts in the station were ruled out . The gun was fixed to the station in such a way that the only way to aim would have been to change the orientation of the entire station . Following the last manned mission to the station , the gun was commanded by the ground to be fired ; some sources say it was fired to depletion , while other sources say three test firings took place during the Salyut 3 mission . Station operations . Only one manned spacecraft , Soyuz 14 , docked with Salyut 3 . One other spacecraft , Soyuz 15 , came within 40 meters of the station , but failed to dock due to a malfunctioning rendezvous system . Launch . The station was launched on June 25 , 1974 by a three stage Proton launch vehicle . 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 . Its initial orbit was 219 km by 270 km above mean sea level , which was considered low . The suspicions of Western observers were raised by the low altitude , combined with the choice of crew from the Air Force , and the use of radio frequencies normally designated for military use . Soyuz 14 . On July 4 , a little over a week after Salyut 3 was launched , the manned spacecraft Soyuz 14 docked with the station , having been launched the previous day . The crew of Soyuz 14 consisted of Commander Pavel Popovich and Flight Engineer Yury Artyukhin . The crew spent 15 days aboard the station . On July 9 , it was reported that the crew activated the Earth - observation cameras , and spent several days taking photos of various locations , including Central Asia . They placed some film in the Earth return capsule . After undocking , Soyuz 14 safely landed on July 19 . Soyuz 15 . The spacecraft Soyuz 15 was launched on August 26 , 1974 , carrying a two man crew consisting of Commander Gennadi Sarafanov and flight engineer Lev Demin . They were intended to be the second crew to man Salyut 3 , but they failed to dock , after their Igla rendezvous system on their Soyuz spacecraft malfunctioned , and they were unable to manually dock . Due to the limited battery life of their Soyuz spacecraft , they were deorbited and landed two days after launch . At the time of the spaceflight , Demin was 48 years old , earning him the record for the oldest person to fly in space up to that point . This record was broken the following year , with Deke Slayton ' s spaceflight as a part of the Apollo – Soyuz Test Project . Unmanned operations . Following the failed docking of Soyuz 15 , it was decided that the Igla docking system needed significant modifications . Due to the amount of time needed to make the changes , and the limited time Salyut 3 had left in orbit due to orbital decay , the next planned mission to the station was cancelled . The spacecraft which would have been used on the third mission to Salyut 3 was later used for the mission Soyuz 20 to Salyut 4 ( a civilian space station ) . Following this decision , on September 23 , 1974 , the station ' s Earth return capsule was released from the station . The ejected capsule was deorbited by small engines . NASA sources report that the parachute of Salyut 3 ' s capsule opened at an altitude of 8 . 4 km . Other sources say the main parachute did not open , and the capsule was deformed upon landing , but that all the film was recoverable . 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 , while other sources say three test firings took place at the end of the mission . The station was deorbited on January 24 , 1975 over the Pacific Ocean .