Editing International Space Station (section)

===Communications and computers===
{{Main|Tracking and Data Relay Satellite|Luch (satellite)}}
{{See also|ThinkPad#Use in space}}The ISS relies on various radio communication systems to provide [[telemetry]] and scientific data links between the station and [[mission control center|mission control centre]]s. Radio links are also used during [[Space rendezvous|rendezvous and docking procedures]] and for audio and video communication between crew members, flight controllers and family members. As a result, the ISS is equipped with internal and external communication systems used for different purposes.<ref name="BoeingComm" />

The Russian Orbital Segment primarily uses the ''[[Lira (ISS)|Lira]]'' antenna mounted on ''Zvezda'' for direct ground communication.<ref name="ISSRG" /><ref>{{cite web|last1=Mathews|first1=Melissa|last2=Hartsfield|first2=James|date=25 March 2005|title=International Space Station Status Report: SS05-015|url=http://www.nasa.gov/home/hqnews/2005/mar/HQ_ss05015_ISS_status_report.html|url-status=dead|archive-url=https://web.archive.org/web/20120111144205/http://www.nasa.gov/home/hqnews/2005/mar/HQ_ss05015_ISS_status_report.html|archive-date=11 January 2012|access-date=11 January 2010|website=NASA News|publisher=NASA}}</ref> It also had the capability to utilize the ''[[Luch (satellite)|Luch]]'' data relay satellite system,<ref name="ISSRG" /> which was in a state of disrepair when the station was built,<ref name="ISSRG" /><ref name="SSSM">{{Cite book|last=Harland|first=David|url=https://archive.org/details/storyofspacestat0000harl|title=The Story of Space Station Mir|publisher=Springer-Verlag New York Incorporated|year=2004|isbn=978-0-387-23011-5|location=New York|url-access=registration}}</ref><ref name="Harvey">{{Cite book|last=Harvey|first=Brian|title=The rebirth of the Russian space program: 50 years after Sputnik, new frontiers|publisher=Springer Praxis Books|year=2007|isbn=978-0-387-71354-0|page=263}}</ref> but was restored to operational status in 2011 and 2012 with the launch of Luch-5A and Luch-5B.<ref>{{cite web|last=Zak|first=Anatoly|date=4 January 2010|title=Space exploration in 2011|url=http://www.russianspaceweb.com/2011.html|url-status=dead|archive-url=https://web.archive.org/web/20100626095747/http://www.russianspaceweb.com/2011.html|archive-date=26 June 2010|access-date=12 January 2010|website=RussianSpaceWeb}}</ref> Additionally, the [[Voskhod-M]] system provides internal telephone communications and VHF radio links to ground control.<ref>{{cite web|date=2 May 2010|title=ISS On-Orbit Status 05/02/10|url=http://www.nasa.gov/directorates/somd/reports/iss_reports/2010/05022010.html|access-date=7 July 2010|publisher=NASA|archive-date=19 January 2012|archive-url=https://web.archive.org/web/20120119101404/http://www.nasa.gov/directorates/heo/reports/iss_reports/2010/05022010.html|url-status=dead}}</ref>

The [[US Orbital Segment]] (USOS) makes use of two separate radio links: [[S band]] (audio, telemetry, commanding – located on the P1/S1 truss) and [[Ku band|K<sub>u</sub> band]] (audio, video and data – located on the [[Z1 truss]]) systems. These transmissions are routed via the United States [[Tracking and Data Relay Satellite]] System (TDRSS) in [[geostationary orbit]], allowing for almost continuous real-time communications with [[Christopher C. Kraft Jr. Mission Control Center]] (MCC-H) in [[Houston]], Texas.<ref name="ISSRG" /><ref name="ISSBook">{{Cite book|last=Catchpole|first=John E.|url={{Google books|VsTdriusftgC|keywords=|text=|plainurl=yes}}|title=The International Space Station: Building for the Future|publisher=Springer-Praxis|year=2008|isbn=978-0-387-78144-0}}</ref><ref name="BoeingComm">{{Cite web|url=http://www.boeing.com/defense-space/space/spacestation/systems/communications_tracking.html|title=Communications and Tracking|publisher=[[Boeing]]|access-date=30 November 2009|url-status=dead|archive-url=https://web.archive.org/web/20080611115319/http://www.boeing.com/defense-space/space/spacestation/systems/communications_tracking.html|archive-date=11 June 2008|website=Integrated Defense Systems}}</ref> Data channels for the Canadarm2, European ''Columbus'' laboratory and Japanese ''Kibō'' modules were originally also routed via the S band and K<sub>u</sub> band systems, with the [[European Data Relay System]] and a similar Japanese system intended to eventually complement the TDRSS in this role.<ref name="ISSBook" /><ref name="JAXA-MOU">{{cite web|date=24 February 1998|title=Memorandum of Understanding Between the National Aeronautics and Space Administration of the United States of America and the Government of Japan Concerning Cooperation on the Civil International Space Station|url=http://www.nasa.gov/mission_pages/station/structure/elements/nasa_japan.html|access-date=19 April 2009|publisher=NASA|archive-date=11 January 2012|archive-url=https://web.archive.org/web/20120111144216/http://www.nasa.gov/mission_pages/station/structure/elements/nasa_japan.html|url-status=dead}}</ref>

[[Ultra high frequency|UHF radio]] is used by astronauts and cosmonauts conducting EVAs and other spacecraft that dock to or undock from the station.<ref name="ISSRG" /> Automated spacecraft are fitted with their own communications equipment; the ATV used a [[laser]] attached to the spacecraft and the Proximity Communications Equipment attached to ''Zvezda'' to accurately dock with the station.<ref name="spaceref-20050228">{{Cite web|url=https://spaceref.com/press-release/issatv-communication-system-flight-on-soyuz/|title=ISS/ATV communication system flight on Soyuz|date=28 February 2005|publisher=[[EADS Astrium]]|access-date=30 November 2009}}</ref><ref name="nsf-20091110">{{Cite news|url=https://www.nasaspaceflight.com/2009/11/sts-129-support-dragon-communication-demo-iss/|title=STS-129 ready to support Dragon communication demo with ISS|last=Bergin|first=Chris|date=10 November 2009|access-date=30 November 2009|url-status=live|archive-url=https://web.archive.org/web/20230811174816/https://www.nasaspaceflight.com/2009/11/sts-129-support-dragon-communication-demo-iss/|archive-date=11 August 2023|work=[[NASASpaceFlight.com]]}}</ref>

{{multiple image
| align             = right
| total_width       = 600
| image1            = ISS-38 EVA-1 Laptops.jpg
| caption1          = An array of laptops in the US lab
| image2            = STS-128 ISS-20 Destiny Canadarm2.jpg
| caption2          = Laptop computers surround the Canadarm2 console.
| image3            = ISS laptop hard drive failure error message.jpg
| caption3          = An error message displays a problem with a hard drive on a laptop aboard the ISS.
}}

The US Orbital Segment of the ISS is equipped with approximately 100 [[commercial off-the-shelf]] laptops running Windows or Linux.<ref name="techrepublic-20160523">{{Cite news|last=Heath|first=Nick|date=23 May 2016|title=From Windows 10, Linux, iPads, iPhones to HoloLens: The tech astronauts use on the ISS|url=https://www.techrepublic.com/article/from-windows-10-linux-ipads-iphones-to-hololens-the-tech-space-station-astronauts-use/|url-status=dead|archive-url=https://web.archive.org/web/20160526014418/https://www.techrepublic.com/article/from-windows-10-linux-ipads-iphones-to-hololens-the-tech-space-station-astronauts-use/|archive-date=26 May 2016|access-date=29 June 2018|work=[[TechRepublic]]}}</ref> These devices are modified to use the station's 28V DC power system and with additional ventilation since heat generated by the devices can stagnate in the weightless environment. NASA prefers to keep a high commonality between laptops and spare parts are kept on the station so astronauts can repair laptops when needed.<ref name="esa-20130813">{{Cite web|last1=Zell|first1=Martin|last2=Suenson|first2=Rosita|date=13 August 2013|title=ESA ISS Science & System – Operations Status Report #150 Increment 36: 13–26 July 2013|url=https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Columbus/ESA_ISS_Science_System_-_Operations_Status_Report_150_Increment_36_13_26_July_2013|url-status=live|archive-url=https://web.archive.org/web/20230812203259/https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Columbus/ESA_ISS_Science_System_-_Operations_Status_Report_150_Increment_36_13_26_July_2013|archive-date=12 August 2023|access-date=11 July 2018|publisher=[[European Space Agency]]}}</ref>

The laptops are divided into two groups: the Portable Computer System (PCS) and Station Support Computers (SSC).

PCS laptops run Linux and are used for connecting to the station's primary Command & Control computer (C&C MDM), which runs on [[Debian]] Linux,<ref name="register-20130510">{{Cite news|last=Thomson|first=Iain|date=10 May 2013|title=Penguins in spa-a-a-ce! ISS dumps Windows for Linux on laptops|url=https://www.theregister.co.uk/2013/05/10/iss_linux_debian_deployment/|url-status=live|archive-url=https://web.archive.org/web/20230811162138/https://www.theregister.com/2013/05/10/iss_linux_debian_deployment/|archive-date=11 August 2023|access-date=15 May 2013|work=[[The Register]]}}</ref> a switch made from Windows in 2013 for reliability and flexibility.<ref>{{Cite news|last=Gunter|first=Joel|date=10 May 2013|title=International Space Station to boldly go with Linux over Windows|url=https://www.telegraph.co.uk/technology/news/10049444/International-Space-Station-to-boldly-go-with-Linux-over-Windows.html|url-access=subscription|url-status=live|archive-url=https://ghostarchive.org/archive/20220110/https://www.telegraph.co.uk/technology/news/10049444/International-Space-Station-to-boldly-go-with-Linux-over-Windows.html|archive-date=10 January 2022|access-date=15 May 2013|work=The Daily Telegraph}}{{cbignore}}</ref> The primary computer supervises the critical systems that keep the station in orbit and supporting life.<ref name="techrepublic-20160523" /> Since the primary computer has no display or keyboards, astronauts use a PCS laptop to connect as remote terminals via a USB to [[MIL-STD-1553|1553]] adapter.<ref name="nasa-20190430">{{Cite web|last=Keeter|first=Bill|date=30 April 2019|title=April 2019 – ISS On-Orbit Status Report|url=https://blogs.nasa.gov/stationreport/2019/04/|url-status=live|archive-url=https://web.archive.org/web/20230810144500/https://blogs.nasa.gov/stationreport/2019/04/|archive-date=10 August 2023|access-date=5 November 2021|website=blogs.nasa.gov|publisher=[[NASA]]}}</ref> The primary computer experienced failures in 2001,<ref name="roundup20010601">{{Cite news|last=Burt|first=Julie|date=1 June 2001|title=Computer problems overcome during STS-100|url=https://www.jsc.nasa.gov/history/roundups/issues/2001-06-01.pdf|url-status=dead|archive-url=https://web.archive.org/web/20161223230857/http://www.jsc.nasa.gov/history/roundups/issues/2001-06-01.pdf|archive-date=23 December 2016|access-date=11 July 2018|work=Space Center Roundup|publisher=NASA}}</ref> 2007,<ref name="reuters20070613">{{Cite news|last=Klotz|first=Irene|date=13 June 2007|title=NASA battles failure of space station computer|url=https://www.reuters.com/article/us-space-shuttle/nasa-battles-failure-of-space-station-computer-idUSN1337907120070614/|url-status=live|archive-url=https://web.archive.org/web/20230810131847/https://www.reuters.com/article/us-space-shuttle/nasa-battles-failure-of-space-station-computer-idUSN1337907120070614|archive-date=10 August 2023|access-date=11 July 2018|work=Reuters}}</ref> and 2017. The 2017 failure required a spacewalk to replace external components.<ref name="huffpost20170522">{{Cite news|last=Klotz|first=Irene|date=22 May 2017|title=NASA Plans Emergency Spacewalk To Replace Key Computer on International Space Station|url=https://www.huffingtonpost.com/entry/iss-computer-failure-spacewalk_us_5922759ce4b03b485cb27a80|url-status=live|archive-url=https://web.archive.org/web/20230811165009/https://www.huffpost.com/entry/iss-computer-failure-spacewalk_n_5922759ce4b03b485cb27a80|archive-date=11 August 2023|access-date=11 July 2018|work=Huffpost|agency=Reuters}}</ref>

SSC laptops are used for everything else on the station, including reviewing procedures, managing scientific experiments, communicating over e-mail or video chat, and for entertainment during downtime.<ref name="techrepublic-20160523" /> SSC laptops connect to the station's [[wireless LAN]] via [[Wi-Fi]], which connects to the ground via the K<sub>u</sub> band. While originally this provided speeds of 10&nbsp;[[Megabit per second|Mbit/s]] download and 3&nbsp;Mbit/s upload from the station,<ref name="tested20121019">{{Cite news|last=Smith|first=Will|date=19 October 2012|title=How Fast is the ISS's Internet? (and Other Space Questions Answered)|url=http://www.tested.com/science/space/449539-how-fast-isss-internet-and-other-space-questions-answered/|url-status=dead|archive-url=https://web.archive.org/web/20140429212053/http://www.tested.com/science/space/449539-how-fast-isss-internet-and-other-space-questions-answered/|archive-date=29 April 2014|access-date=29 April 2014|work=Tested.com}}</ref> NASA upgraded the system in 2019 and increased the speeds to 600&nbsp;Mbit/s.<ref name="universetoday-20190825">{{Cite news|last=Williams|first=Matt|date=25 August 2019|title=Upgraded ISS Now Has a 600 Megabit per Second Internet Connection|url=https://www.universetoday.com/143221/upgraded-iss-now-has-a-600-megabit-per-second-internet-connection/|url-status=live|archive-url=https://web.archive.org/web/20230906210636/https://www.universetoday.com/143221/upgraded-iss-now-has-a-600-megabit-per-second-internet-connection/|archive-date=6 September 2023|access-date=23 June 2020|work=Universe Today}}</ref> ISS crew members have access to the [[internet]].<ref name="Kuksov">{{Cite web|last1=Kuksov|first1=Igor|date=13 September 2019|title=Internet in space: Is there Net on Mars?|url=https://www.kaspersky.co.uk/blog/internet-in-space/16690/|url-status=live|archive-url=https://web.archive.org/web/20230831095806/https://www.kaspersky.co.uk/blog/internet-in-space/16690/|archive-date=31 August 2023|access-date=5 December 2022|website=Kaspersky Daily|publisher=[[Kaspersky Lab]]}}</ref><ref name="ScienceAlert">{{Cite news|date=26 August 2019|title=The ISS Now Has Better Internet Than Most of Us After Its Latest Upgrade|url=https://www.sciencealert.com/the-iss-now-has-better-internet-than-most-of-us-after-its-latest-upgrade|url-status=live|archive-url=https://web.archive.org/web/20231102150646/https://www.sciencealert.com/the-iss-now-has-better-internet-than-most-of-us-after-its-latest-upgrade|archive-date=2 November 2023|access-date=5 December 2022|work=ScienceAlert}}</ref>