Editing International Space Station (section)

===Orientation===
''Zvezda'' uses gyroscopes ([[reaction wheel]]s) and thrusters to turn itself. Gyroscopes do not require propellant; instead they use electricity to 'store' momentum in flywheels by turning in the opposite direction to the station's movement. The USOS has its own computer-controlled gyroscopes to handle its extra mass. When gyroscopes [[Control moment gyroscope#Saturation|'saturate']], thrusters are used to cancel out the stored momentum. In February 2005, during Expedition 10, an incorrect command was sent to the station's computer, using about 14&nbsp;kilograms of propellant before the fault was noticed and fixed. When attitude control computers in the ROS and USOS fail to communicate properly, this can result in a rare 'force fight' where the ROS GNC computer must ignore the USOS counterpart, which itself has no thrusters.<ref>{{cite web|date=7 October 2003|title=Russian / US GNC Force Fight|url=http://pims.grc.nasa.gov/pimsdocs/public/ISS%20Handbook/hb_qs_vehicle_RussianUSGNCForceFight.pdf|url-status=dead|archive-url=https://web.archive.org/web/20120720193844/http://pims.grc.nasa.gov/pimsdocs/public/ISS%20Handbook/hb_qs_vehicle_RussianUSGNCForceFight.pdf|archive-date=20 July 2012|access-date=1 May 2012|website=pims.grc.nasa.gov|publisher=[[Glenn Research Center]]}}</ref><ref name="iss-report-05-07">{{Cite web|url=http://spaceflight.nasa.gov/spacenews/reports/issreports/2005/iss05-7.html|title=International Space Station Status Report #05-7|date=11 February 2005|publisher=[[NASA]]|access-date=23 November 2008|url-status=dead|archive-url=https://web.archive.org/web/20050317194246/http://spaceflight.nasa.gov/spacenews/reports/issreports/2005/iss05-7.html|archive-date=17 March 2005}}</ref><ref name="nasa-dynamics-report">{{Cite tech report|url=https://ntrs.nasa.gov/api/citations/20030038806/downloads/20030038806.pdf|title=Dynamics and Control of Attitude, Power, and Momentum for a Spacecraft Using Flywheels and Control Moment Gyroscopes|last1=Roithmayr|first1=Carlos M.|last2=Karlgaard|first2=Christopher D.|last3=Kumar|first3=Renjith R.|last4=Seywald|first4=Hans|last5=Bose|first5=David M.|date=April 2003|publisher=[[NASA]]|location=Hampton, Virginia|id=TP-2003-212178|access-date=12 July 2011|url-status=live|archive-url=https://web.archive.org/web/20230810132103/https://ntrs.nasa.gov/api/citations/20030038806/downloads/20030038806.pdf|archive-date=10 August 2023}}</ref>

Docked spacecraft can also be used to maintain station attitude, such as for troubleshooting or during the [[STS-117|installation of the S3/S4 truss]], which provides electrical power and data interfaces for the station's electronics.<ref name="nsf-20070614">{{Cite news|url=https://www.nasaspaceflight.com/2007/06/atlantis-ready-to-support-iss-troubleshooting/|title=Atlantis ready to support ISS troubleshooting|last=Bergin|first=Chris|date=14 June 2007|access-date=6 March 2009|url-status=live|archive-url=https://web.archive.org/web/20100131051544/http://www.nasaspaceflight.com/2007/06/atlantis-ready-to-support-iss-troubleshooting/|archive-date=31 January 2010|work=[[NASASpaceFlight.com]]}}</ref>