View source for Salyut 3

{{short description|Soviet space station (1974–1975)}}
{{Infobox space station
 | station                = Salyut 3<br>(OPS-2 / Almaz 2)
 | insignia               = Salyut_program_insignia.svg
 | insignia_size          = 160px
 | sign                   = Salyut 3
 | crew                   = 2
 | launch                 = 25 June 1974, 04:15:00&nbsp;[[Coordinated Universal Time|UTC]]<ref name=RSW/>
 | carrier_rocket         = [[Proton-K]] No.&nbsp;283-01
 | launch_pad             = [[Baikonur Cosmodrome|Baikonur]], [[Baikonur Cosmodrome Site 81|Site 81/23]]<ref name=RSW/>
 | reentry                = 24 January 1975
 | mass                   = {{cvt|18900|kg|lk=on}} at launch<ref name=MHH/>
 | length                 = {{cvt|14.55|m}}<ref name=MHH/>
 | diameter               = {{cvt|4.15|m}} max.<ref name=MHH/>
 | volume                 = {{cvt|90|m3}}<ref name=MHH/>
 | perigee                = Initial: {{cvt|219|km|mi nmi}}<ref name=TheContinuing>Bond (2002).</ref><br>Final: {{cvt|268|km|mi nmi}}<ref name=NASAcatOrbits />
 | apogee                 = Initial: {{cvt|270|km|mi nmi}}<ref name=TheContinuing /><br>Final: {{cvt|272|km|mi nmi}}<ref name=NASAcatOrbits />
 | inclination            = 51.6°<ref name=NASAcatOrbits/>
 | period                 = 89.1 minutes<ref name=NASAcatOrbits>{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1974-046A|title=Salyut 3 - Trajectory details|publisher=NASA}}</ref>
 | in_orbit               = 213 days
 | occupied               = 15 days
 | COSPAR_ID              = <!-- Wikidata -->
 | SATCAT                 = <!-- Wikidata -->
 | as_of                  = de-orbit and reentry
 | configuration_image    = Almaz drawing.svg
 | configuration_caption  = Salyut 3 diagram
}}

'''Salyut 3''' ({{langx|ru|Салют-3||Salute 3}}, also known as '''OPS-2'''<ref name=RSW>{{cite web|url=http://www.russianspaceweb.com/almaz_ops2.html|title=OPS-2 (Salyut-3)|first=Anatoly |last=Zak|work=RussianSpaceWeb.com}}</ref> or '''Almaz 2'''<ref name=MHH>Portree (1995).</ref>) was a [[Soviet Union|Soviet]] [[space station]] launched on 25 June 1974. It was the second [[Almaz]] military [[space station]], and the first such station to be launched successfully.<ref name=MHH/> It was included in the [[Salyut]] program to disguise its true military nature.<ref name=SoyuzBook>Hall and Shayer (2003).</ref> 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.<ref name=LeavingEarth>Zimmerman (2003).</ref>

It attained an altitude of 219 to 270&nbsp;km on launch and NASA reported its final orbital altitude was 268 to 272&nbsp;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 [[atmospheric reentry|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.<ref name="LeavingEarth" /> These civilian stations, were also known as Long-term Orbital Stations (DOS). Successors to ''Salyut 1''  included the unsuccessful ''[[DOS-2]]'' in 1972 and ''[[Kosmos 557|DOS-3]]'' in 1974, followed by the successful launches of ''[[Salyut 4]]'', ''[[Salyut 6]]'', and ''[[Salyut 7]]''.<ref name="MHH" />

The military space stations, known as [[Almaz]] stations or Orbital Piloted Stations (OPS), were similar in size and shape to the civilian DOS stations. However, their designs, attributed to [[Vladimir Chelomey]], were significantly different.<ref name="LeavingEarth" /> To conceal their military purpose, these stations were also publicly designated as Salyut stations. The first Almaz station, ''[[Salyut 2]]'', launched in April 1973 but failed within days of reaching orbit and was never crewed.<ref name="MHH" />

==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 {{Convert|90|m3}}.<ref name=MHH-specs/> It had two solar arrays, one docking port, and two main engines, each of which could produce {{Convert|400|kgf|lk=on}} of thrust.<ref name=MHH-specs/> Its launch mass was {{Convert|18900|kg}}.<ref name=MHH/>

The station came equipped with a shower, a standing sleeping station, as well as a foldaway bed.<ref name=MHH/> The floor was covered with [[hook and loop fastener|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 [[Compact Cassette|cassette tapes]].<ref name=MHH-specs/> Exercise equipment included a treadmill and [[Pingvin exercise suit]].<ref name=MHH-specs/>  The first water-recycling facilities were tested on the station; the system was called Priboy.<ref name=MHH-specs/>

===Earth-observation cameras===
The work compartment was dominated by the ''Agat-1'' Earth-observation telescope, which had a [[focal length]] of {{Convert|6.375|m}} and an [[optical resolution]] better than three metres, according to post-Soviet sources;<ref>See Zak's website, as well as Siddiqi p.593. Another NASA source, Portree p.69, states the focal length was 10 metres; but Portree's document preceded Siddiqi's by several years, during which time more information about the specifications was gathered.</ref> NASA historian Siddiqi has speculated that given the size of the telescope's mirror, it likely had a resolution better than {{Convert|1|m|spell=in}}.<ref>Siddiqi p. 593.</ref> The telescope was used in conjunction with a wide-film camera and primarily for military reconnaissance.<ref>Siddiqi, p.593; also Portree, p.69.</ref> 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.<ref name=MHH-specs>Portree, p.69</ref>

The cosmonauts were able to [[Photographic processing|develop film]] while on the station. Important or interesting images were printed and then scanned by a TV imaging system for broadcast to Earth.<ref name=MHH-specs/> They needed as little as 30 minutes to shoot, develop, and scan a photograph.<ref name=MHH-specs/> Less important images were packed into a small Earth-return capsule, which could be ejected from the station.<ref name=MHH-specs/>

In addition to the Agat-1 camera, other cameras on board included a topographical camera, a star camera, and a Volga infrared camera with a resolution of {{Convert|100|m}}.<ref name=RSW/> Cosmonaut [[Pavel Popovich]], who visited the station as the commander of [[Soyuz 14]], recalled that the station was equipped with 14 cameras.<ref name=RSW/>

===On-board gun===
The Salyut 3, although called a "civilian" station, was equipped with a "self-defence" gun which had been designed for use aboard the station, and whose design is attributed to [[Alexander Nudelman]].<ref name=RSW/> Some accounts claim the station was equipped with a Nudelman-Rikhter "Vulkan" gun, which was a variant of the [[Nudelman-Rikhter NR-23|23 mm Nudelman]] aircraft cannon, or possibly a [[Nudelman-Rikhter NR-30|Nudelman NR-30]] 30&nbsp;mm gun.<ref name="Olberg">{{Cite web |title=James Oberg, ''Space Power Theory'', Ch. 2 |url=http://space.au.af.mil/books/oberg/ch02.pdf |url-status=dead |archive-url=https://web.archive.org/web/20180712205157/http://space.au.af.mil/books/oberg/ch02.pdf |archive-date=2018-07-12 |access-date=2006-07-20}}</ref> Later Russian sources indicate that the gun was the virtually unknown (in the West) [[Rikhter R-23]].<ref>Широкоград А.Б. (2001) ''История авиационного вооружения'' Харвест (Shirokograd A.B. (2001) ''Istorya aviatsionnogo vooruzhenia'' Harvest. {{ISBN|985-433-695-6}}) (''History of aircraft armament'')
p. 162</ref> These claims have reportedly been verified by [[Pavel Popovich]], who had visited the station in orbit, as commander of [[Soyuz 14]].<ref name=Olberg/> Due to the potential shaking of the station, in-orbit tests of the weapon with cosmonauts in the station were ruled out.<ref name=RSW/> 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.<ref name=RSW/><ref name=Olberg/> Following the last crewed mission to the station, the gun was commanded by the ground to be fired; some sources say it was fired to depletion,<ref name=Olberg/> while other sources say three test firings took place during the Salyut 3 mission.<ref name=RSW/>

==Station operations==
Only one crewed spacecraft, [[Soyuz 14]], docked with Salyut 3. One other spacecraft, [[Soyuz 15]], came within 40 metres of the station,<ref name=RSW/> but failed to dock due to a malfunctioning rendezvous system.<ref name=RSW/>

===Launch===
The station was launched on 25 June 1974 by a three-stage [[Proton (rocket family)|Proton launch vehicle]].<ref name=MHH/>

Salyut 3 was the first space station to maintain its constant orientation relative to the Earth's surface.<ref name=RSW/> To achieve that, as many as 500,000 firings of the attitude control thrusters had been performed.<ref name=RSW/> Its initial orbit was 219&nbsp;km by 270&nbsp;km [[above mean sea level]], which was considered low.<ref name=TheContinuing/> The suspicions of Western observers were raised by the low altitude, combined with the choice of a crew from the Soviet Air Force, and the use of radio frequencies normally designated for military use.<ref name=TheContinuing/>

===Soyuz 14===
{{main|Soyuz 14}}
On 4 July, a little over a week after Salyut 3 was launched, the crewed spacecraft [[Soyuz 14]] docked with the station, having been launched the previous day.<ref name=EA-Soyuz14>{{cite web|url=http://www.astronautix.com/flights/soyuz14.htm|title=Soyuz 14|publisher=Encyclopedia Astronautica|url-status=dead|archive-url=https://web.archive.org/web/20090822031202/http://www.astronautix.com/flights/soyuz14.htm|archive-date=2009-08-22}}</ref> 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.<ref name=RSW/> They placed some film in the Earth return capsule.<ref name=RSW/> After undocking, Soyuz 14 safely landed on 19 July.<ref name=EA-Soyuz14/>

===Soyuz 15===
{{main|Soyuz 15}}
The spacecraft [[Soyuz 15]] was launched on 26 August 1974, carrying a two-man crew consisting of commander [[Gennadi Sarafanov]] and flight engineer [[Lev Demin]].<ref name=RSW/> They were intended to be the second crew to man Salyut 3, but failed to dock. The Igla rendezvous system on their Soyuz spacecraft malfunctioned, and the crew was unable to dock manually.<ref name=MHH-27>Portree, p. 27</ref> Due to the limited battery life of their Soyuz spacecraft, they de-orbited and landed two days after launch.<ref name=MHH-27/> 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.<ref name=EA-Soyuz15>{{cite web|url=http://www.astronautix.com/flights/soyuz15.htm|title=Soyuz 15|publisher=Encyclopedia Astronautica|url-status=dead|archive-url=https://web.archive.org/web/20101130000515/http://astronautix.com/flights/soyuz15.htm|archive-date=2010-11-30}}</ref> This record was broken the following year, with [[Deke Slayton]]'s spaceflight as a part of the [[Apollo–Soyuz Test Project]].<ref name=EA-Soyuz15/>

===Uncrewed operations===
Following the failed docking of Soyuz 15, it was decided that the Igla docking system needed significant modifications.<ref name=EA-Soyuz15/> 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.<ref name=EA-Soyuz15/> 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).<ref name=EA-Soyuz15/>

Following this decision, on 23 September 1974, the station's Earth return capsule was released. 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&nbsp;km.<ref name=MHH-specs/> Other sources say the main parachute did not open, and the capsule was deformed upon landing, but that all the film was recoverable.<ref name=EA-S3>{{cite web|url=http://www.astronautix.com/details/sal31678.htm|archive-url=https://web.archive.org/web/20021119120055/http://astronautix.com/details/sal31678.htm|url-status=dead|archive-date=November 19, 2002|title=sal31678|publisher=Encyclopedia Astronautica}}</ref>

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,<ref name=Olberg/> while other sources say three test firings took place at the end of the mission.<ref name=RSW/>

The station was deorbited on 24 January 1975 over the [[Pacific Ocean]].<ref name=RSW/>

==See also==
{{Portal|Soviet Union|Spaceflight}}
*[[TKS spacecraft]]

==Notes==
{{Reflist}}

==References==
*{{cite book|title=Challenge to Apollo: The Soviet Union and the Space Race, 1945-1974|author=Siddiqi, Asif A.|publisher=NASA|year=2000}} SP-2000-4408. [https://history.nasa.gov/SP-4408pt1.pdf Part 2 (page 1-499)], [https://history.nasa.gov/SP-4408pt2.pdf Part 1 (page 500-1011)]
*{{cite book|title=Leaving Earth: Space Stations, Rival Superpowers, and the Quest for Interplanetary Travel|author=Robert Zimmerman|pages=[https://archive.org/details/leavingearth00robe/page/544 544]|publisher=[[Joseph Henry Press]]|date=September 3, 2003|isbn=0-309-08548-9|url-access=registration|url=https://archive.org/details/leavingearth00robe/page/544}}
*{{cite web|url=http://ston.jsc.nasa.gov/collections/TRS/_techrep/RP1357.pdf|title=Mir Hardware Heritage|publisher=NASA|author=D.S.F. Portree|date=March 1995|url-status=dead|archive-url=https://web.archive.org/web/20090907191412/http://ston.jsc.nasa.gov/collections/TRS/_techrep/RP1357.pdf|archive-date=2009-09-07}}
*{{cite book|title=Soyuz: a universal spacecraft|author=Rex Hall, David Shayler|publisher=Springer|year=2003|pages=459|isbn=1-85233-657-9}}
*{{cite book|title=The continuing story of the International Space Station|author=Peter Bond|pages=416|publisher=Springer|date=20 June 2002|isbn=1-85233-567-X|url=https://archive.org/details/continuingstoryo0000bond|url-access=registration}}
*{{cite web|url=http://www.russianspaceweb.com/almaz_ops2.html|title=OPS-2 (Salyut-3)|author=Anatoly Zak|publisher=RussianSpaceWeb.com}}

==External links==
*[https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19870012563_1987012563.pdf Soviet Space Stations as Analogs - NASA report (PDF format)]

{{Almaz Program}}
{{Salyut Program}}
{{Space stations}}
{{Orbital launches in 1974}}

[[Category:Salyut programme]]
[[Category:1974 in the Soviet Union]]
[[Category:1974 in spaceflight]]
[[Category:Space weapons]]
[[Category:Crewed spacecraft]]
[[Category:Soviet military spacecraft]]
[[Category:Almaz program]]
[[Category:Spacecraft launched in 1974]]
[[Category:Spacecraft which reentered in 1975]]

[[de:Saljut#Saljut 3 (Almas 2)]]