GPS Block IIF
{{Short description|Operational generation of GPS satellites}}
{{Use American English|date=March 2014}}
{{Use dmy dates|date=February 2021}}
{{Infobox spacecraft class
| name = GPS Block IIF
| names_list = GPS IIF
| image = Navstar-2F.jpg
| caption = Artist's impression of a Block IIF GPS satellite in orbit
| manufacturer = Boeing
| country = United States
| bus =
| applications = Satellite navigation
| orbits = Semi-synchronous MEO
| operator = United States Air Force
| lifetime = 12 years (planned)
| derivedfrom =
| derivatives =
| Preceded = GPS Block IIR
| Succeeded = GPS Block III
| status = Production completed
| built = 12
| orders = 0
| launched = 12
| operational = 11
| retired =
| failed =
| lost =
| first = GPS IIF SV-1
{{nowrap|28 May 2010, 03:00 UTC}}
| last = GPS IIF-12
{{nowrap|5 February 2016, 13:38 UTC}}
| lastretired =
| mass = {{cvt|1633|kg}} {{cite web|title=Global Positioning System|url=http://www.boeing.com/space/global-positioning-system/|publisher=Boeing|access-date=6 May 2016}}
| power = 1952 watts (end of life)
| batteries =
| equipment =
}}
GPS Block IIF, or GPS IIF is an interim class of GPS (satellite) which were used to bridge the gap between previous Navstar Global Positioning System generations until the GPS Block III satellites became operational. They were built by Boeing, operated by the United States Air Force, and launched by the United Launch Alliance (ULA) using Evolved Expendable Launch Vehicles (EELV).{{cite web|title=Global Positioning System (GPS) IIF|url=http://www.boeing.com/defense-space/space/gps/index.html|publisher=Boeing|access-date=27 May 2010}} They are the final component of the Block II GPS constellation to be launched. On 5 February 2016, the final Block IIF satellite was successfully launched, completing the series.
The spacecraft have a mass of {{cvt|1633|kg}} and a design life of 12 years. Like earlier GPS satellites, Block IIF spacecraft operate in semi-synchronous medium Earth orbits, with an altitude of approximately {{cvt|20460|km}}, and an orbital period of twelve hours.
The satellites supplement and partially replace the GPS Block IIA satellites that were launched between 1990 and 1997 with a design life of 7.5 years.{{cite web |url=http://www.dailytech.com/First+Block+2F+GPS+Satellite+Launched+Needed+to+Prevent+System+Failure/article18483.htm|title=First Block 2F GPS Satellite Launched, Needed to Prevent System Failure |publisher=DailyTech|access-date=2010-05-30|archive-url=https://web.archive.org/web/20100530023659/http://www.dailytech.com/First+Block+2F+GPS+Satellite+Launched+Needed+to+Prevent+System+Failure/article18483.htm|archive-date=May 30, 2010|url-status=dead}} The final satellite of the Block IIA series was decommissioned on 09 October 2019.{{cite web|url=https://insidegnss.com/farewell-to-a-great-generation-gps-iia/|title=Farewell to a Great Generation: GPS IIA|date=15 April 2020 |publisher=Inside GNSS|access-date=14 May 2023}} The operational constellation now includes Block IIR, IIRM, IIF and III variants.
Because the Evolved Expendable Launch Vehicles are more powerful than the Delta II, which was used to orbit earlier Block II GPS satellites, they can place the satellites directly into their operational orbits. As a result, Block IIF satellites do not carry apogee kick motors. The original contract for Block IIF, signed in 1996, called for 33 spacecraft. This was later reduced to 12, and program delays and technical problems pushed the first launch from 2006 to 2010.{{cite web|last=Pike|first=John|title=GPS Block II F|url=http://www.globalsecurity.org/space/systems/gps_2f.htm |publisher=Globalsecurity.org|access-date=27 May 2010}}
New characteristics
- Broadcasting L5 "safety of life" navigation signal demonstrated on USA-203
- Broadcasting a new M-code signal
- Doubling in the predicted accuracy
- Better resistance to jamming
- Reprogrammable processors that can receive software uploads
- The first GPS satellites not to have Selective Availability (SA) hardware installed, which degraded civilian accuracy when turned on in the original satellite fleet
Launch history
Overall, 12 GPS Block IIF satellites were launched, all of which are currently operational:
| class="wikitable" style="margin: 1em auto 1em auto; font-size:90%; width:90%;"
|+ GPS Block IIF satellites |
| style="width:8%; text-align:center; background:#BBB" | Satellite
! style="width:7%; text-align:center; background:#BBB" | USA designation ! style="width:15%; text-align:center; background:#BBB" | Launch date ! style="width:15%; text-align:center; background:#BBB" | Rocket ! style="width:15%; text-align:center; background:#BBB" | Launch site ! style="width:10%; text-align:center; background:#BBB" | Status ! style="width:25%; text-align:center; background:#BBB" | Notes ! style="width:5%; text-align:center; background:#BBB" | Ref. |
|---|
| style="text-align:center;" nowrap | GPS IIF-1 (Polaris)
| style="text-align:center;" | USA-213 | style="text-align:right;" | 28 May 2010, 03:00 | style="text-align:left;" | Delta IV-M+(4,2), s/n D349 | style="text-align:left;" | Cape Canaveral, SLC-37B | {{yes|In service}} | style="text-align:left;" | | style="text-align:left;" | {{cite web|title=Mission Overview|url=http://www.ulalaunch.com/uploads/docs/Mission_Booklets/DIV/div_gpsiifsv1_mob.pdf|work=Delta IV Launches GPS IIF SV-1|publisher=United Launch Alliance|date=28 May 2010|access-date=29 October 2015|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304053628/http://www.ulalaunch.com/uploads/docs/Mission_Booklets/DIV/div_gpsiifsv1_mob.pdf|url-status=dead}}{{cite web|url=http://www.space.com/missionlaunches/air-force-new-gps-satellite-launch-100527.html|title=Air Force Launches Advanced New GPS Satellite|author=Tariq Malik|publisher=SPACE.com|date=28 May 2010}}{{cite web|title=ULA Marks Delta 50th Anniversary with Successful Delta IV GPS IIF SV-1 Launch|url=http://www.ulalaunch.com/ula-marks-delta-50th-anniversary-with.aspx?archived=True&Category=2|publisher=United Launch Alliance|date=28 May 2010|access-date=29 October 2015}} |
| style="text-align:center;" | GPS IIF-2 (Sirius)
| style="text-align:center;" | USA-232 | style="text-align:right;" | 16 July 2011, 06:41 | style="text-align:left;" | Delta IV-M+(4,2), s/n D355 | style="text-align:left;" | Cape Canaveral, SLC-37B | {{no|Retired | style="text-align:left;" | |
| style="text-align:center;" | GPS IIF-3 (Arcturus)
| style="text-align:center;" | USA-239 | style="text-align:right;" | 4 October 2012, 12:10 | style="text-align:left;" | Delta IV-M+(4,2), s/n D361 | style="text-align:left;" | Cape Canaveral, SLC-37B | {{yes|In service}} | style="text-align:left;" | This launch came shortly before the 10th anniversary of the inaugural Delta IV launch. |
| style="text-align:center;" | GPS IIF-4 (Vega)
| style="text-align:center;" | USA-242 | style="text-align:right;" | 15 May 2013, 21:38 | style="text-align:left;" | Atlas V 401, s/n AV-039 | style="text-align:left;" | Cape Canaveral, SLC-41 | {{yes|In service}} | style="text-align:left;" | | style="text-align:left;" | {{cite web|title=ULA Atlas V sets sail with new GPS satellite|url=http://www.nasaspaceflight.com/2013/05/ula-atlas-v-launch-new-gps-satellite/|publisher=NASASpaceFlight.com |date=15 May 2013|access-date=15 May 2013}}{{cite web|title=Orbit Data and Resources on Active GNSS Satellites|date=21 August 2012 |url=http://gpsworld.com/the-almanac/|publisher=GPS World|access-date=6 March 2014}} |
| style="text-align:center;" | GPS IIF-5 (Canopus)
| style="text-align:center;" | USA-248 | style="text-align:right;" nowrap | 21 February 2014, 01:59 | style="text-align:left;" | Delta IV-M+(4,2), s/n D365 | style="text-align:left;" | Cape Canaveral, SLC-37B | {{yes|In service}} | style="text-align:left;" | |
| style="text-align:center;" | GPS IIF-6 (Rigel)
| style="text-align:center;" | USA-251 | style="text-align:right;" | 17 May 2014, 00:03 | style="text-align:left;" | Delta IV-M+(4,2), s/n D366 | style="text-align:left;" | Cape Canaveral, SLC-37B | {{yes|In service}} | style="text-align:left;" | |
| style="text-align:center;" | GPS IIF-7 (Capella)
| style="text-align:center;" | USA-256 | style="text-align:right;" | 2 August 2014, 03:23 | style="text-align:left;" | Atlas V 401, s/n AV-048 | style="text-align:left;" | Cape Canaveral, SLC-41 | {{yes|In service}} | style="text-align:left;" | | style="text-align:left;" | {{cite web|url=http://www.boeing.com/boeing/defense-space/space/bss/launch/launch_sched.page|title=Boeing Satellite Launch Schedule|publisher=Boeing |access-date=17 May 2014|url-status=dead|archive-url=https://web.archive.org/web/20140611071855/http://www.boeing.com/boeing/defense-space/space/bss/launch/launch_sched.page|archive-date=June 11, 2014}}{{cite web|title=Atlas V to Launch GPS IIF-7|url=http://www.ulalaunch.com/atlas-v-to-launch-gps-iif7.aspx?title=Atlas+V+to+Launch+GPS+IIF-7|publisher=United Launch Alliance|access-date=2 August 2014}} |
| style="text-align:center;" | GPS IIF-8 (Spica)
| style="text-align:center;" | USA-258 | style="text-align:right;" | 29 October 2014, 17:21 | style="text-align:left;" | Atlas V 401, s/n AV-050 | style="text-align:left;" | Cape Canaveral, SLC-41 | {{yes|In service}} | style="text-align:left;" | | style="text-align:left;" | {{cite web |title=Atlas V successfully vaults satellite to orbit |url=http://www.floridatoday.com/story/tech/science/space/2014/08/02/ula-atlas-v-blasts-off-cape-canaveral-gps-satellite/13502135/ |publisher=Florida Today |date= 2 August 2014|access-date=29 October 2015}}{{cite web|url=http://www.navcen.uscg.gov/?Do=gpsShowNanu&num=2014090|title=NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2014090|publisher=United States Coast Guard|date=12 December 2014|access-date=29 October 2015}} |
| style="text-align:center;" | GPS IIF-9 (Deneb)
| style="text-align:center;" | USA-260 | style="text-align:right;" | 25 March 2015, 18:36 | style="text-align:left;" | Delta IV-M+(4,2), s/n D371 | style="text-align:left;" | Cape Canaveral, SLC-37B | {{yes|In service}} | style="text-align:left;" | | style="text-align:left;" | {{cite web|title=United Launch Alliance GPS IIF-9|url=http://www.ulalaunch.com/uploads/docs/Mission_Booklets/DIV/div_gpsiif9_mob.pdf|access-date=25 March 2015}} |
| style="text-align:center;" | GPS IIF-10 (Antares)
| style="text-align:center;" | USA-262 | style="text-align:right;" | 15 July 2015, 15:36 | style="text-align:left;" | Atlas V 401, s/n AV-055 | style="text-align:left;" | Cape Canaveral, SLC-41 | {{yes|In service}} | style="text-align:left;" | |
| style="text-align:center;" | GPS IIF-11 (Altair)
| style="text-align:center;" | USA-265 | style="text-align:right;" | 31 October 2015, 16:13 | style="text-align:left;" | Atlas V 401, s/n AV-060 | style="text-align:left;" | Cape Canaveral, SLC-41 | {{yes|In service}} | style="text-align:left;" | | style="text-align:left;" | {{cite web|title=Atlas V to Launch GPS IIF-11|url=http://spaceflightnow.com/2015/10/29/av-060-journal/|date=31 October 2015|access-date=31 October 2015}} |
| style="text-align:center;" | GPS IIF-12 (Betelgeuse)
| style="text-align:center;" | USA-266 | style="text-align:right;" | 5 February 2016, 13:38 | style="text-align:left;" | Atlas V 401, s/n AV-057 | style="text-align:left;" | Cape Canaveral, SLC-41 | {{yes|In service}} | style="text-align:left;" | | style="text-align:left;" | {{cite web|title=New GPS satellite begins transmitting to users around the globe|url=http://spaceflightnow.com/2016/03/09/new-gps-satellite-begins-transmitting-to-users-around-the-globe/|access-date=9 March 2016}} |
| colspan="7" style="font-size: smaller;" | (Last update: September 26, 2024) |