Editing Global Positioning System (section)

=== Timeline and modernization ===
{{prose|section|date=July 2023}}
[[File:GPS-0012 San Diego Air & Space Museum.jpg|thumb|[[Test article (aerospace)|Qualification vehicle]] for GPS Block II on display in [[San Diego Air & Space Museum|San Diego]] – the only vehicle on public display.<ref>{{Cite web |last=Czopek |first=Frank |title=GPS 12 |url=https://www.ion.org/museum/item_view.cfm?cid=4&scid=15&iid=23 |access-date=October 14, 2024 |website=Institute of Navigation – Navigation Museum}}</ref>]]
{|class="wikitable"
|+ Summary of satellites<ref>[http://www.insidegnss.com/node/918 GPS Wing Reaches GPS III IBR Milestone] {{Webarchive|url=https://web.archive.org/web/20130523204537/http://www.insidegnss.com/node/918 |date=May 23, 2013 }} in ''[[Inside GNSS]]'' November 10, 2008</ref><ref>{{cite web |url=http://www.navcen.uscg.gov/?Do=constellationStatus |title=GPS Constellation Status for 08/26/2015 |access-date=August 26, 2015 |archive-url=https://web.archive.org/web/20150905082039/http://www.navcen.uscg.gov/?Do=constellationStatus |archive-date=September 5, 2015 |url-status=live }}</ref><ref>{{cite web|url=http://spaceflightnow.com/2015/10/31/recap-story-three-atlas-5-launch-successes-in-one-month/|title=Recap story: Three Atlas 5 launch successes in one month|date=October 31, 2015 |access-date=October 31, 2015|archive-url=https://web.archive.org/web/20151101182626/http://spaceflightnow.com/2015/10/31/recap-story-three-atlas-5-launch-successes-in-one-month/|archive-date=November 1, 2015|url-status=live}}</ref>
! rowspan="2" | Block || rowspan="2" | Launch <br />period || colspan="4" | Satellite launches || rowspan="2" | Currently<br /> in orbit<br /> and healthy
|-
! Success || Failure || In<br>preparation || Planned
|-
! [[GPS Block I|I]]
| 1978–1985 || 10 || 1 || 0 ||  0 || 0
|-
! [[GPS Block II|II]]
| 1989–1990 || 9 || 0 || 0 || 0 || 0
|-
! [[GPS Block IIA|IIA]]
| 1990–1997 || 19 || 0 || 0 || 0 || 0
|-
! [[GPS Block IIR|IIR]]
| 1997–2004 ||12|| 1 || 0 || 0 || 7
|-
! [[GPS Block IIR-M|IIR-M]]
| 2005–2009 || 8 || 0 || 0 || 0 || 7
|-
! [[GPS Block IIF|IIF]]
| 2010–2016  || 12 || 0 || 0 || 0 || 11
|-
! [[GPS Block IIIA|IIIA]]
| 2018–  || 6 || 0 || 4 || 0 || 6
|-
! [[GPS Block IIIF|IIIF]]
| —          || 0 || 0 || 0 || 22 || 0
|-
! colspan="2" | Total
| 76 || 2 || 4 || 22 || 31
|-
| colspan="7" style="font-size: smaller;" | (Last update: September 26, 2024)<br />
[[USA-203]] from Block IIR-M is unhealthy<br /><ref>{{cite web|url=http://www.navcen.uscg.gov/?pageName=gpsAlmanacs|title=GPS almanacs|publisher=Navcen.uscg.gov|access-date=October 15, 2010|archive-url=https://web.archive.org/web/20100923053920/http://www.navcen.uscg.gov/?pageName=gpsAlmanacs|archive-date=September 23, 2010|url-status=live}}</ref> For a more complete list, see ''[[List of GPS satellites]]''
|}
* In 1972, the U.S. Air Force Central Inertial Guidance Test Facility (Holloman Air Force Base) conducted developmental flight tests of four prototype GPS receivers in a Y configuration over [[White Sands Missile Range]], using ground-based pseudo-satellites.<ref>{{cite web|url=https://www.rewiresecurity.co.uk/blog/gps-global-positioning-system-satellites|title=Origin of Global Positioning System (GPS)|website=Rewire Security|access-date=February 9, 2017|archive-url=https://web.archive.org/web/20170211080457/https://www.rewiresecurity.co.uk/blog/gps-global-positioning-system-satellites|archive-date=February 11, 2017|url-status=live}}</ref>
* In 1978, the first experimental Block-I GPS satellite was launched.<ref name="ieee2008" />
* In 1983, after Soviet Union interceptor aircraft shot down the civilian airliner [[Korean Air Flight 007|KAL 007]] that strayed into [[prohibited airspace]] because of navigational errors, killing all 269&nbsp;people on board, U.S. President [[Ronald Reagan]] announced that GPS would be made available for civilian uses once it was completed,<ref name=":2" /><ref>{{cite book |last1=Schroeer |first1=Dietrich |url={{google books|plainurl=y|id=I7JRAAAAMAAJ}} |title=Technology Transfer |last2=Elena |first2=Mirco |publisher=Ashgate |year=2000 |isbn=978-0-7546-2045-7 |page=80 |access-date=May 25, 2008}}</ref><ref>{{cite book|url={{google books|plainurl=y|id=_wpUAAAAMAAJ}}|title=The Precision Revolution: GPS and the Future of Aerial Warfare|author1=Michael Russell Rip |author2=James M. Hasik |publisher=Naval Institute Press|year=2002|isbn=978-1-55750-973-4|access-date=May 25, 2008}}</ref> although it had been publicly known as early as 1979, that the CA code (Coarse/Acquisition code) would be available to civilian users.<ref name="breeze-19790916-91">{{cite news |last1=Dore |first1=Richard |date=September 16, 1979 |title=Navstar – Global system will provide accurate data for navigation |url=https://www.newspapers.com/article/the-daily-breeze-navstar-global-system/125171841/ |url-status=live |archive-url=https://web.archive.org/web/20230523113102/https://www.newspapers.com/article/the-daily-breeze-navstar-global-system/125171841/ |archive-date=May 23, 2023 |access-date=May 23, 2023 |newspaper=[[The Daily Breeze]] |location=[[Torrance, California]] |page=91 |via=Newspapers.com}}</ref><ref name="breeze-19790916-97">{{cite news |last1=Dore |first1=Richard |title=Satellite technology key to GPS |url=https://www.newspapers.com/article/the-daily-breeze-satellite-technology-ke/125171984/ |access-date=May 23, 2023 |newspaper=[[The Daily Breeze]] |date=September 16, 1979 |archive-url=https://web.archive.org/web/20230523113718/https://www.newspapers.com/article/the-daily-breeze-satellite-technology-ke/125171984/ |archive-date=May 23, 2023 |url-status=live |page=97 |location=[[Torrance, California]] |via=Newspapers.com }}</ref>
* By 1985, ten more experimental Block-I satellites had been launched to validate the concept.
* Beginning in 1988, command and control of these satellites was moved from [[Onizuka AFS]], California to the [[2nd Space Operations Squadron|2nd Satellite Control Squadron]] (2SCS) located at [[Schriever Space Force Base]] in [[Colorado Springs, Colorado]].<ref>{{cite web|title=AF Space Command Chronology |url=http://www.afspc.af.mil/heritage/chronology.asp |publisher=USAF Space Command |access-date=June 20, 2011 |archive-url=https://web.archive.org/web/20110817001221/http://www.afspc.af.mil/heritage/chronology.asp |archive-date=August 17, 2011 }}</ref><ref>{{cite web|title=FactSheet: 2nd Space Operations Squadron |url=http://www.schriever.af.mil/library/factsheets/factsheet.asp?id=4045 |publisher=USAF Space Command |access-date=June 20, 2011 |archive-url=https://web.archive.org/web/20110611205433/http://www.schriever.af.mil/library/factsheets/factsheet.asp?id=4045 |archive-date=June 11, 2011 }}</ref>
* On February 14, 1989, the first modern Block-II satellite was launched.
* The [[Gulf War]] from 1990 to 1991 was the first conflict in which the military widely used GPS.<ref>[https://www.rand.org/pubs/monograph_reports/MR614.html The Global Positioning System: Assessing National Policies] {{Webarchive|url=https://web.archive.org/web/20151230101234/http://www.rand.org/pubs/monograph_reports/MR614.html |date=December 30, 2015 }}, p.245. RAND corporation</ref>
* In 1991, DARPA's project to create a miniature GPS receiver successfully ended, replacing the previous {{cvt|16|kg|||}} military receivers with a {{cvt|1.25|kg|||}} all-digital handheld GPS receiver.<ref name=Alexandrow />
* In 1991, [[TomTom]], a Dutch sat-nav manufacturer was founded.
* In 1992, the [[2nd Space Wing]], which originally managed the system, was inactivated and replaced by the [[50th Space Wing]].
* By December 1993, GPS achieved [[initial operational capability]] (IOC), with a full constellation (24 satellites) available and providing the Standard Positioning Service (SPS).<ref name="IOCFOC">{{cite web|url=http://tycho.usno.navy.mil/gpsinfo.html|title=USNO NAVSTAR Global Positioning System|publisher=U.S. Naval Observatory|access-date=January 7, 2011|archive-url=https://web.archive.org/web/20110126200746/http://tycho.usno.navy.mil/gpsinfo.html|archive-date=January 26, 2011}}</ref>
* Full Operational Capability (FOC) was declared by [[Air Force Space Command]] (AFSPC) in April 1995, signifying full availability of the military's secure Precise Positioning Service (PPS).<ref name="IOCFOC" />
* In 1996, recognizing the importance of GPS to civilian users as well as military users, U.S. President [[Bill Clinton]] issued a policy directive<ref>[[National Archives and Records Administration]]. [http://clinton4.nara.gov/textonly/WH/EOP/OSTP/html/gps-factsheet.html U.S. Global Positioning System Policy] {{Webarchive|url=https://web.archive.org/web/20060406125528/http://clinton4.nara.gov/textonly/WH/EOP/OSTP/html/gps-factsheet.html |date=April 6, 2006 }}. March 29, 1996.</ref> declaring GPS a [[dual-use]] system and establishing an [[Interagency GPS Executive Board]] to manage it as a national asset.
* In 1998, United States Vice President [[Al Gore]] announced plans to upgrade GPS with two new civilian signals for enhanced user accuracy and reliability, particularly with respect to aviation safety, and in 2000 the [[United States Congress]] authorized the effort, referring to it as ''[[GPS III]]''.
* On May 2, 2000 "Selective Availability" was discontinued as a result of the 1996 executive order, allowing civilian users to receive a non-degraded signal globally.
* In 2004, the United States government signed an agreement with the European Community establishing cooperation related to GPS and Europe's [[Galileo (satellite navigation)|Galileo system]].
* In 2004, United States President [[George W. Bush]] updated the national policy and replaced the executive board with the National Executive Committee for Space-Based Positioning, Navigation, and Timing.<ref>{{cite web|url=http://pnt.gov/ |title=National Executive Committee for Space-Based Positioning, Navigation, and Timing |publisher=Pnt.gov |access-date=October 15, 2010 |archive-url=https://web.archive.org/web/20100528124826/http://pnt.gov/ |archive-date=May 28, 2010 }}</ref><!-- [[National Space-Based Positioning, Navigation, and Timing Executive Committee]] -->
* In November 2004, [[Qualcomm]] announced successful tests of [[assisted GPS]] for [[mobile phones]].<ref>{{cite web|url=http://www.3g.co.uk/PR/November2004/8641.htm|title=Assisted-GPS Test Calls for 3G WCDMA Networks|date=November 10, 2004|publisher=3g.co.uk|access-date=November 24, 2010|archive-url=https://web.archive.org/web/20101127041459/http://www.3g.co.uk/PR/November2004/8641.htm|archive-date=November 27, 2010}}</ref>
* In 2005, the first modernized GPS satellite was launched and began transmitting a second civilian signal (L2C) for enhanced user performance.<ref>{{cite web|title=Press release: First Modernized GPS Satellite Built by Lockheed Martin Launched Successfully by the U.S. Air Force – Sep 26, 2005|url=http://news.lockheedmartin.com/2005-09-26-First-Modernized-GPS-Satellite-Built-by-Lockheed-Martin-Launched-Successfully-by-the-U-S-Air-Force|publisher=Lockheed Martin|ref=September 26, 2005|language=en|access-date=August 9, 2017|archive-url=https://web.archive.org/web/20170810090450/http://news.lockheedmartin.com/2005-09-26-First-Modernized-GPS-Satellite-Built-by-Lockheed-Martin-Launched-Successfully-by-the-U-S-Air-Force|archive-date=August 10, 2017|url-status=live}}</ref>
* On September 14, 2007, the aging mainframe-based [[Ground segment]] Control System was transferred to the new Architecture Evolution Plan.<ref>{{cite web|url=https://www.losangeles.spaceforce.mil/?id=123068412 |title=losangeles.af.mil |publisher=losangeles.af.mil |date=September 17, 2007 |access-date=October 15, 2010 |url-status=live |archive-url=https://web.archive.org/web/20110511192610/http://www.losangeles.af.mil/news/story.asp?id=123068412 |archive-date=May 11, 2011 }}</ref>
* On May 19, 2009, the United States [[Government Accountability Office]] issued a report warning that some GPS satellites could fail as soon as 2010.<ref>{{cite news|url=https://www.theguardian.com/technology/2009/may/19/gps-close-to-breakdown|title=GPS system 'close to breakdown'|last=Johnson|first=Bobbie|newspaper=The Guardian|date=May 19, 2009|access-date=December 8, 2009|location=London|archive-url=https://web.archive.org/web/20130926155833/http://www.theguardian.com/technology/2009/may/19/gps-close-to-breakdown|archive-date=September 26, 2013|url-status=live}}</ref>
* On May 21, 2009, the [[Air Force Space Command]] allayed fears of GPS failure, saying: "There's only a small risk we will not continue to exceed our performance standard."<ref>{{cite news|url=https://abcnews.go.com/Technology/AheadoftheCurve/story?id=7647002&page=1|title=Air Force Responds to GPS Outage Concerns|last=Coursey|first=David|date=May 21, 2009|work=ABC News|access-date=May 22, 2009|archive-url=https://web.archive.org/web/20090523175214/http://abcnews.go.com/Technology/AheadoftheCurve/story?id=7647002&page=1|archive-date=May 23, 2009|url-status=live}}</ref>
* On January 11, 2010, an update of ground control systems caused a software incompatibility with 8,000 to 10,000 military receivers manufactured by a division of Trimble Navigation Limited of Sunnyvale, California.{{clarify|date=March 2022|reason=What was the outcome?}}<ref>{{cite news|url=https://www.huffingtonpost.com/2010/06/01/air-force-gps-problem-gli_n_595727.html|title=Air Force GPS Problem: Glitch Shows How Much U.S. Military Relies On GPS|work=The Huffington Post|date=June 1, 2010 |first1=Dan |last1=Elliott |access-date=October 15, 2010|archive-url=https://web.archive.org/web/20110511200835/https://www.huffingtonpost.com/2010/06/01/air-force-gps-problem-gli_n_595727.html |archive-date=May 11, 2011 }}</ref>
* On February 25, 2010,<ref>{{cite web|url=https://www.losangeles.spaceforce.mil/?id=123192234 |title=Contract Award for Next Generation GPS Control Segment Announced |website=Los Angeles Air Force Base |date= February 25, 2010 |access-date=December 14, 2012 |url-status=live |archive-url=https://web.archive.org/web/20130723134812/http://www.losangeles.af.mil/news/story_print.asp?id=123192234 |archive-date=July 23, 2013 }}</ref> the U.S. Air Force awarded the contract to [[Raytheon Company]] to develop the GPS Next Generation Operational Control System (OCX) to improve accuracy and availability of GPS navigation signals, and serve as a critical part of GPS modernization.
* July 24, 2020, operation of the GPS constellation is transferred to the newly established [[United States Space Force|U.S. Space Force]] as part of its establishment.<ref name="2nd Space Operations Squadron">{{Cite web |title=2nd Space Operations Squadron |url=https://www.petersonschriever.spaceforce.mil/About-Us/Fact-Sheets/Display/Article/2814232/2nd-space-operations-squadron/ |access-date=2024-10-15 |website=Peterson and Schriever Space Force Base |language=en-US}}</ref> [[File:2nd Space Operations Squadron emblem.png|thumb|266x266px|Emblem of the [[2nd Space Operations Squadron]] – the unit responsible for operating the constellation ]]
* On October 13, 2023, the Space Force activated [[Positioning, Navigation, and Timing Integrated Mission Delta (Provisional)|PNT Delta (Provisional)]] to manage US [[Satellite navigation|navigation warfare]] assets. [[2nd Space Operations Squadron|2SOPS]] and GPS operations were realigned under this new [[Structure of the United States Space Force|Delta]].<ref name="2nd Space Operations Squadron"/>