Editing Shuttle–Mir program (section)

===Phases Two and Three: ISS (1998–present)===
{{main|International Space Station}}
With the landing of [[Space Shuttle Discovery|''Discovery'']] on June 12, 1998, the Phase One program concluded. Techniques and equipment developed during the program assisted the development of Phase Two: initial assembly of the International Space Station (ISS). The arrival of the [[Destiny (ISS module)|''Destiny'' Laboratory Module]] in 2001 marked the end of Phase Two and the start of Phase Three, the final outfitting of the station, completed in 2012.<ref name = "ISS Phases">{{cite web|last1=Esquivel|first1 =Gerald|title=ISS Phases I, II and III|date=23 March 2003|publisher=NASA|url=http://pdlprod3.hosc.msfc.nasa.gov/D-aboutiss/D1.html|access-date=2007-06-27|archive-url=https://web.archive.org/web/20071214221840/http://pdlprod3.hosc.msfc.nasa.gov/D-aboutiss/D1.html|archive-date=2007-12-14|url-status=dead}}</ref> 

In 2015, a reconfiguration of the American segment was completed to allow its docking ports to accommodate NASA-sponsored commercial crew vehicles, that were expected to start visiting the ISS in 2018.<ref name="ISS Recongfig 2015">{{cite news|last1=Harding|first1=Pete|url=http://www.nasaspaceflight.com/2015/05/iss-program-station-reconfiguration-future-crew-vehicles/|title=ISS relocates PMM in reconfiguration for future crew vehicles|work=NASA Spaceflight.com|date=26 May 2015|access-date=2015-06-13|archive-url=https://web.archive.org/web/20150601070251/http://www.nasaspaceflight.com/2015/05/iss-program-station-reconfiguration-future-crew-vehicles/|archive-date=1 June 2015|url-status=live}}</ref>

{{As of|June 2015}}, the ISS has a pressurized volume of {{convert|915|m3}}, and its pressurized modules total {{convert|51|m}} in length, plus a large truss structure that spans {{convert|109|m}}, making it the largest spacecraft ever assembled.<ref name="ISS facts & figures">{{cite web|last1=Garcia|first1=Mark|title=ISS Facts and Figures|publisher=NASA|work=International Space Station|date=30 April 2015|url=http://www.nasa.gov/mission_pages/station/main/onthestation/facts_and_figures.html|access-date=2015-06-13|archive-url=https://web.archive.org/web/20150603040411/http://www.nasa.gov/mission_pages/station/main/onthestation/facts_and_figures.html|archive-date=3 June 2015|url-status=live}}</ref> The completed station consists of five laboratories and is able to support six crew members. With over {{convert|332|m3}} of habitable volume and a mass of {{convert|400000|kg}} the completed station is almost twice the size of the combined Shuttle–''Mir'' spacecraft.<ref name="ISS facts & figures"/>

Phases Two and Three are intended to continue both international cooperation in space and zero-gravity scientific research, particularly regarding long-duration spaceflight. By spring 2015, [[Russian Federal Space Agency|Roscosmos]], NASA, and the [[Canadian Space Agency]] (CSA) have agreed to extend the ISS's mission from 2020 to 2024.<ref name="ISS mission extension">{{cite news|last1=Clark|first1=Stephen|url=http://spaceflightnow.com/2015/02/24/russian-space-agency-endorses-iss-until-2024/|title=Russian Space Agency Endorses ISS Until 2024|work=Spaceflight Now|date=24 February 2015|access-date=2015-06-14|archive-url=https://web.archive.org/web/20150614045957/http://spaceflightnow.com/2015/02/24/russian-space-agency-endorses-iss-until-2024/|archive-date=14 June 2015|url-status=live}}</ref> 

In 2018 that was then extended out to 2030.<ref>{{Cite web|url=https://spacenews.com/senate-passes-commercial-space-bill-2/|title=Senate passes commercial space bill|date=2018-12-21|website=SpaceNews.com|language=en-US|access-date=2019-03-26|archive-date=2021-09-27|archive-url=https://web.archive.org/web/20210927033414/https://spacenews.com/senate-passes-commercial-space-bill-2/|url-status=live}}</ref> The results of this research will provide considerable information for long-duration expeditions to the [[Moon]] and flights to [[Mars]].<ref name="ISS International Cooperation">{{cite web|last1=Garcia|first1=Mark|title=International Cooperation|work=International Space Station|publisher=NASA|date=30 April 2015|url=http://www.nasa.gov/mission_pages/station/cooperation/index.html|access-date=2015-06-13|archive-url=https://web.archive.org/web/20150528114837/http://www.nasa.gov/mission_pages/station/cooperation/index.html|archive-date=28 May 2015|url-status=live}}</ref>

Following the intentional deorbiting of ''Mir'' on 23 March 2001, the ISS became the only space station in orbit around Earth.<ref name="Mir deorbited">{{cite news|last1=Boyle|first1=Alan|title=Russia bids farewell to Mir|work=NBC News|date=23 March 2001|url=http://www.nbcnews.com/id/3077781/ns/technology_and_science-space/t/russia-bids-farewell-mir/#.VXyY2BNVhHw|access-date=2015-06-13|location=New York|archive-url=https://web.archive.org/web/20150615065153/http://www.nbcnews.com/id/3077781/ns/technology_and_science-space/t/russia-bids-farewell-mir/|archive-date=15 June 2015|url-status=dead}}</ref> It retained that distinction until the launch of Chinese [[Tiangong-1]] space laboratory on 29 September 2011.<ref name="Tiangong-1">{{cite news|last1=Malik|first1=Tariq|url=http://www.space.com/13120-china-tiangong-1-space-laboratory-facts-figures.html|title=China's Tiangong 1 Space Lab: Questions & Answers|date=29 September 2011|work=Space.com|access-date=2015-06-13|archive-url=https://web.archive.org/web/20150926072528/http://m.space.com/13120-china-tiangong-1-space-laboratory-facts-figures.html|archive-date=26 September 2015|url-status=live}}</ref> 

''Mir''{{'s}} legacy lives on in the station, bringing together five space agencies in the cause of exploration and allowing those space agencies to prepare for their next leap into space, to the Moon, Mars and beyond.<ref name="Mir's Legacy">{{cite news|last1=Cabbage|first1=Michael|title=NASA outlines plans for Moon and Mars|newspaper=Orlando Sentinel|date=31 July 2005|url=http://www.orlandosentinel.com/news/custom/space/orl-asec-moon073105,0,3136666.htmlstory?coll=orl-home-promo|access-date=2009-09-17|archive-url=https://web.archive.org/web/20070312170234/http://www.orlandosentinel.com/news/custom/space/orl-asec-moon073105%2C0%2C3136666.htmlstory?coll=orl-home-promo|archive-date=12 March 2007|url-status=dead}}</ref>