View source for Russian Orbital Segment

{{Use dmy dates|date=September 2022}}
{{short description|Russian components of the International Space Station}}
[[File:Iss before and after undocking of progress m-um from prichal (cropped).png|thumb|ISS Russian orbital segment after docking of UM Prichal module|250px]]
[[File:Nikolai Budarin in a sleep station in Zvezda.jpg|350px|thumb|Cosmonaut [[Nikolai Budarin]] working inside one of the crew quarters aboard ''[[Zvezda (ISS module)|Zvezda]]'' service module]]
The '''Russian Orbital Segment''' ('''ROS''') is the name given to the components of the [[International Space Station]] (ISS) constructed in [[Russia]] and operated by the Russian [[Roscosmos]]. The ROS handles Guidance, Navigation, and Control for the entire Station.<ref name="Navigation">{{cite web|url=http://www.esa.int/export/esaHS/ESAOXX0VMOC_iss_0.html|title=DMS-R: ESA's Data Management System for the Russian Segment of the ISS|website=Esa.int|access-date=24 February 2016}}</ref>

==Current composition==
[[File:View of the ISS taken during Crew-2 flyaround (ISS066-E-079547).jpg|thumb|right|Dorsal side of the ROS in November 2021]]
The segment currently consists of six modules, which together essentially comprise the base configuration of the cancelled Russian space station [[Mir-2|''Mir''-2]].<ref>{{cite web|url=http://www.astronautix.com/craft/mir2.htm|archive-url=https://web.archive.org/web/20021119114700/http://astronautix.com/craft/mir2.htm|url-status=dead|archive-date=19 November 2002|title=Mir-2|publisher=Encyclopaedia Astronautica|access-date=29 January 2009|date=31 July 2008}}</ref> The segment is controlled directly from Roskosmos's [[RKA Mission Control Center|Mission Control Center]] in [[Moscow]]. The six modules are (in order of launch):

* ''[[Zarya (ISS module)|Zarya]]'' (dawn)
* [[Zvezda (ISS module)|''Zvezda'']] (star)
* [[Poisk (ISS module)|''Poisk'']] (search)
* [[Rassvet (ISS module)|''Rassvet'']] (sunrise, dawn)
* [[Nauka (ISS module)|''Nauka'']] (science)
* [[Prichal (ISS module)|''Prichal'']] (berth)

The first module, ''Zarya'', otherwise known as the Functional Cargo Block or FGB, was the first component of the ISS to be launched, and provided the early station configuration with electrical power, storage, propulsion, and navigation guidance, until a short time after the Russian service module ''Zvezda'' docked and control was transferred. ''Zvezda'' contains the [[European Space Agency|ESA]] built DMS-R Data Management System.<ref name="EsaComputer">{{cite web|url=http://www.esa.int/esapub/onstation/onstation17/os17_chapter6.pdf|title=Exercising Control 49 months of DMS-R Operations|website=Esa.int|access-date=24 February 2016}}</ref> Now primarily used for storage, ''Zarya'' provides ports for [[Soyuz (spacecraft)|Soyuz]] and [[Progress (spacecraft)|Progress]] spacecraft and the European ATV to dock to the station. Ships boosting the station's orbit dock to the aft port (the rear port according to the station's normal orientation and direction of travel). The FGB is a descendant of the TKS spacecraft designed for the Russian Salyut program. 5.4 tons of propellant fuel can be stored and transferred automatically to and from ships docked. ''Zarya'' was originally intended as a module for the Russian Mir space station,{{Citation needed|date=May 2014}} but was not flown as of the end of the Mir-1 program. Developed by Russia and the former Soviet Union, construction of ''Zarya'' was funded by the United States and NASA,<ref>{{cite web|url=http://www.nasa.gov/mission_pages/station/structure/elements/fgb.html#.U22GvfldV8E |title=Zarya &#124; NASA |website=Nasa.gov |date=20 November 1998 |access-date=24 February 2016}}</ref> and ''Zarya'' remains a US-owned module.<ref>{{cite web|url=http://www.energia.ru/en/iss/rs/zarya.html |title=S.P. Korolev RSC Energia - ISS - ISS Russian Segment |website=Energia.ru |access-date=24 February 2016}}</ref>

The second module, ''Zvezda'', is the station's Service Module - it provides a living environment for the crew, contains the ISS's main engine system, and provides a docking port for Soyuz, Progress and [[Automated Transfer Vehicle]] spacecraft.<ref>{{cite web|url=http://www.nasa.gov/mission_pages/station/structure/elements/sm.html|title=Zvezda Service Module|publisher=NASA|date=14 October 2006|access-date=29 January 2009}}</ref>

The fourth module to be launched, ''Poisk'', is similar to ''Pirs''. Redundancy in airlocks allowed one airlock to be repaired internally and externally whilst crew use the other airlock to exit and re-enter the station.

The fifth module to be launched, ''Rassvet'', is primarily used for cargo storage and as a docking port for visiting spacecraft.

The sixth module to be launched, ''Nauka'', also known as the Multipurpose Laboratory Module, is the main laboratory space of the ROS. A backup flight article for FGB-based ''[[Zarya (ISS module)|Zarya]]'', known in production as FGB-2, was originally planned to serve as the Universal Docking Module, though its construction had been halted at 70% completion in the late 1990s. It occupies the former location of ''Pirs'' on ''Zvezda's'' nadir port.

The seventh module to be launched, ''Prichal'' also known as Uzlovoy Module is a nodal module that has a pressurized spherical ball-shaped design with six hybrid docking ports. It is attached to the nadir port of the ''Nauka'' module.

==Former module==
''[[Pirs (ISS module)|Pirs]]'', launched on 14 September 2001, was the third module of the ROS to be launched. It functioned as the ROS's airlock, storing EVA spacesuits and providing the equipment necessary for cosmonauts to exit the space station. It also served as a docking compartment for Soyuz and Progress spacecraft. It was decommissioned and undocked by [[Progress MS-16]] on 26 July 2021, and burned up in the atmosphere, to make way for the ''[[Nauka (ISS module)|Nauka]]'' module.<ref>{{cite web|url=http://www.nasa.gov/mission_pages/station/structure/elements/pirs.html|title=Pirs Docking Compartment|publisher=NASA|access-date=29 January 2009|date=10 May 2006}}</ref>

== Formerly proposed modules ==
{{More citations needed|date=September 2022}}
On 17 June 2009, the Russian Federal Space Agency (Roskosmos) presented to NASA and the other ISS partners a proposal to add additional modules to the Russian segment to ensure its viability past 2016 or even 2020.

It was planned that the two larger modules, nominally referred to as NEM 1 and 2, would be lifted to orbit via [[Angara A5]] launchers in the mid-2020s and would be attached to the port and starboard sides of the Nodal Module, leaving its aft docking port accessible for possible future expandability or using it for commercial vehicles like [[SpaceX Dragon 2|Crew Dragon]] via an [[International Docking Adapter]] attached on top of this port and its nadir port accessible for docking by Soyuz or Progress spacecraft. Because of the proximity of the Nodal Module to the planned attachment point of MRM-1 on the nadir docking port of ''[[Zarya (ISS module)|Zarya]]'' FGB to facilitate docking of Soyuz and Progress spacecraft, the module's forward-facing port will be unusable. {{As of| 2021|January}}, neither Roscosmos nor NASA have provided further details of these modules or verification that they have been officially funded by the Russian government or added to the ISS launch manifest schedule.<ref>{{cite web|title=Novosti Kosmonavtiki article, "Программа развития российского сегмента МКС" (ISS segment development program) [English summary of Russian technical article]|publisher=Kosmonavtka|url=http://suzymchale.com/kosmonavtka/issfutmod.html}}</ref><ref>{{cite web|url=http://www.space-travel.com/reports/Russia_Needs_Billions_More_To_Complete_Its_ISS_Segment_999.html|title=Russia Needs Billions More To Complete {{sic|I|t's|nolink=y}} ISS Segment|publisher=Space-Travel.com|access-date=29 January 2009|date=14 April 2008}}</ref><ref>{{cite web|url=http://www.novosti-kosmonavtiki.ru/content/numbers/306/index.shtml|title=Program for Development of the Russian ISS Segment|publisher=Novosti Kosmonavtiki|author=Sergei Shamsutdinov|date=July 2008|access-date=15 February 2009|language=ru|archive-url=https://web.archive.org/web/20110606065940/http://www.novosti-kosmonavtiki.ru/content/numbers/306/11.shtml|archive-date=6 June 2011}}</ref>

Continued international collaboration relating to the ISS has been thrown into doubt by the [[2022 Russian invasion of Ukraine]] and related sanctions on Russia.<ref>{{cite journal |last1=Witze |first1=Alexandra |title=Russia's invasion of Ukraine is redrawing the geopolitics of space |url=https://www.nature.com/articles/d41586-022-00727-x |journal=Nature |access-date=13 March 2022 |language=en |doi=10.1038/d41586-022-00727-x |date=11 March 2022|pmid=35277688 |s2cid=247407886 |url-access=subscription }}</ref>

Due to the different orbit from ISS, the future [[Russian Orbital Service Station]] is planned to be a completely new space station, without inheriting any module from the Russian Orbital Segment or adding new modules to the ISS. In such a case, the planned characteristics of the ISS's ''Prichal'' module will be of no use and an identical node module will then be constructed for the ROSS station.<ref>{{cite web | url=https://forum.nasaspaceflight.com/index.php?topic=53721.msg2314818#msg2314818 | title=Russian Orbital Service Station (ROSS) Development }}</ref><ref>{{cite web | url=https://www.nasaspaceflight.com/2021/04/roscosmos-future-for-mid-2020s/ | title=Roscosmos discusses ISS withdrawal strategy and new space station for mid-2020s | date=30 April 2021 }}</ref> The NEM-1 and 2 will be repurposed and flown directly to the new space station.{{citation needed|date=September 2022}}

The Oka-T-MKS was a planned companion module to the ISS. Reported {{as of|2012|12|lc=y}} to be under construction, its development has been significantly delayed. The module would be free-floating most of the time as an autonomous orbital space laboratory for the conduction of experiments, and dock with the ISS for experiment maintenance about every 180 days. The Oka-T-MKS space laboratory was contracted to Energia by Roscosmos in 2012. Originally projected for a 2015 launch date, this has been pushed back indefinitely and some evidence suggests that, unable to locate significant development partnerships, its development has been abandoned.<ref>{{cite news |publisher= SpaceDaily |url= http://www.spacedaily.com/reports/Russia_to_build_autonomous_space_lab_999.html |title= Russia to build autonomous space lab |date= 21 December 2012 |access-date= 22 December 2012 }}</ref><ref>{{Cite web|url=https://space.skyrocket.de/doc_sdat/oka-t.htm|title=Oka-T}}</ref>

==See also==
*[[Orbital Piloted Assembly and Experiment Complex]] - proposed separation of parts of ROS into a separate space station
* [[Scientific research on the ISS]]

==References==
{{Reflist|2}}

==External links==
* [http://www.energia.ru/en/iss/researches/iss-researches.html Science Research on ISS Russian Segment] - S.P. Korolev RSC Energia

{{s-start}}
{{Succession box
| before = [[Mir-2]]
| title  = Russian Orbital Segment
| years  = November 1993 - 2015/2024
| after  =
}}
{{end}}

{{ISS_modules}}
{{Space stations}}
{{Russian space program}}
{{Russian human spaceflight programs}}

[[Category:Russian components of the International Space Station|*]]
[[Category:Roscosmos]]