Editing Space station (section)

===International Space Station===
{{main|International Space Station}}
[[File:The station pictured from the SpaceX Crew Dragon 5 (cropped).jpg|thumb|upright=1.2|View of the [[International Space Station]] in 2021]]
The ISS is divided into two main sections, the [[Russian Orbital Segment]] (ROS) and the [[US Orbital Segment]] (USOS). The first module of the ISS, [[Zarya (ISS module)|Zarya]], was launched in 1998.<ref name="CASIS">{{Cite web|title=History and Timeline of the ISS|website=[[Center for the Advancement of Science in Space]]|url=https://www.iss-casis.org/about/iss-timeline/|access-date=8 February 2018|archive-date=25 February 2018|archive-url=https://web.archive.org/web/20180225195017/https://www.iss-casis.org/about/iss-timeline/|url-status=dead}}</ref>

The Russian Orbital Segment's "second-generation" modules were able to launch on [[Proton (rocket)|Proton]], fly to the correct orbit, and dock themselves without human intervention.<ref>{{cite web |url=http://www.usu.edu/mae/aerospace/publications/JDSC_RoadToAutonomy.pdf |title=Mechanical and Aerospace Engineering |publisher=Usu.edu |access-date=2012-08-13 }}{{Dead link|date=October 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> Connections are automatically made for power, data, gases, and propellants. The Russian autonomous approach allows the assembly of space stations prior to the launch of crew.

The Russian "second-generation" modules are able to be reconfigured to suit changing needs. As of 2009, [[RKK Energia]] was considering the removal and reuse of some modules of the ROS on the [[Orbital Piloted Assembly and Experiment Complex]] after the end of mission is reached for the ISS.<ref>{{cite news |url=http://news.bbc.co.uk/2/hi/science/nature/8064060.stm |title=Russia 'to save its ISS modules' |work=BBC News |date=22 May 2009 |access-date=23 May 2009 |first=Anatoly |last=Zak}}</ref> However, in September 2017, the head of Roscosmos said that the technical feasibility of separating the station to form OPSEK had been studied, and there were now no plans to separate the Russian segment from the ISS.<ref>{{cite web |last=Foust |first=Jeff |url=http://spacenews.com/international-partners-in-no-rush-regarding-future-of-iss/ |title=International partners in no rush regarding future of ISS |website=[[SpaceNews]] |date=25 September 2017 |access-date=26 October 2017 }}</ref>

In contrast, the main US modules launched on the [[Space Shuttle]] and were attached to the ISS by crews during [[Extra-vehicular activity|EVAs]]. Connections for electrical power, data, propulsion, and cooling fluids are also made at this time, resulting in an integrated block of modules that is not designed for disassembly and must be deorbited as one mass.<ref>{{cite book|url=https://www.nap.edu/read/9794/chapter/8|isbn=978-0-309-06938-0|publisher=National Academies Press|year=2000|pages=28–30|first=Thomas|last=Kelly|title=Engineering Challenges to the Long-Term Operation of the International Space Station|display-authors=etal}}</ref>

[[Axiom Station]] is a planned commercial space station that will begin as a single module docked to the ISS. [[Axiom Space]] gained NASA approval for the venture in January 2020. The first module, the Payload Power Transfer Module (PPTM), is expected to be launched to the ISS no earlier than 2027.<ref name="sn-20241218">{{cite web |last=Foust |first=Jeff |url=https://spacenews.com/axiom-space-revises-space-station-assembly-plans/ |title=Axiom Space revises space station assembly plans |work=[[SpaceNews]] |date=18 December 2024 |access-date=18 December 2024}}</ref> PPTM will remain at the ISS until the launch of Axiom's Habitat One (Hab-1) module about one year later, after which it will detach from the ISS to join with Hab-1.<ref name="sn-20241218" />