 Artist's impression of a Block IIF GPS satellite in orbit | |||
| Manufacturer | Boeing | ||
|---|---|---|---|
| Country of origin | United States | ||
| Operator | United States Air Force | ||
| Applications | Satellite navigation | ||
| Specifications | |||
| Launch mass | 1,633 kg (3,600 lb)[1] | ||
| Power | 1952watts (end of life)[1] | ||
| Regime | Semi-synchronousMEO | ||
| Design life | 12 years (planned) | ||
| Production | |||
| Status | Production completed | ||
| On order | 0 | ||
| Built | 12 | ||
| Launched | 12 | ||
| Operational | 11 | ||
| Maiden launch | GPS IIF SV-1 28 May 2010, 03:00UTC | ||
| Last launch | GPS IIF-12 5 February 2016, 13:38 UTC | ||
| |||
GPS Block IIF, orGPS IIF is an interim class ofGPS (satellite) which were used to bridge the gap between previous NavstarGlobal Positioning System generations until theGPS Block III satellites became operational. They were built byBoeing, operated by theUnited States Air Force, and launched by theUnited Launch Alliance (ULA) usingEvolved Expendable Launch Vehicles (EELV).[2] 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 1,633 kg (3,600 lb) and a design life of 12 years. Like earlier GPS satellites, Block IIF spacecraft operate insemi-synchronousmedium Earth orbits, with an altitude of approximately 20,460 km (12,710 mi), and anorbital period of twelve hours.
The satellites supplement and partially replace theGPS Block IIA satellites that were launched between 1990 and 1997 with a design life of 7.5 years.[3] The final satellite of the Block IIA series was decommissioned on 09 October 2019.[4] Theoperational constellation now includes Block IIR, IIRM, IIF and III variants.
Because the Evolved Expendable Launch Vehicles are more powerful than theDelta 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 carryapogee 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.[5]
Overall, 12 GPS Block IIF satellites were launched, all of which are currently operational:
| Satellite | USA designation | Launch date (UTC) | Rocket | Launch site | Status | Notes | Ref. |
|---|---|---|---|---|---|---|---|
| GPS IIF-1 | USA-213 | 28 May 2010, 03:00 | Delta IV-M+(4,2), s/n D349 | Cape Canaveral,SLC-37B | In service | [6][7][8] | |
| GPS IIF-2 | USA-232 | 16 July 2011, 06:41 | Delta IV-M+(4,2), s/n D355 | Cape Canaveral, SLC-37B | Retired 10 August 2023[9][10] | [11] | |
| GPS IIF-3 | USA-239 | 4 October 2012, 12:10 | Delta IV-M+(4,2), s/n D361 | Cape Canaveral, SLC-37B | In service | This launch came shortly before the 10th anniversary of the inaugural Delta IV launch. | [12] |
| GPS IIF-4 | USA-242 | 15 May 2013, 21:38 | Atlas V 401, s/n AV-039 | Cape Canaveral,SLC-41 | In service | [13][14] | |
| GPS IIF-5 | USA-248 | 21 February 2014, 01:59 | Delta IV-M+(4,2), s/n D365 | Cape Canaveral, SLC-37B | In service | [15] | |
| GPS IIF-6 | USA-251 | 17 May 2014, 00:03 | Delta IV-M+(4,2), s/n D366 | Cape Canaveral, SLC-37B | In service | [16] | |
| GPS IIF-7 | USA-256 | 2 August 2014, 03:23 | Atlas V 401, s/n AV-048 | Cape Canaveral, SLC-41 | In service | [17][18] | |
| GPS IIF-8 | USA-258 | 29 October 2014, 17:21 | Atlas V 401, s/n AV-050 | Cape Canaveral, SLC-41 | In service | [19][20] | |
| GPS IIF-9 | USA-260 | 25 March 2015, 18:36 | Delta IV-M+(4,2), s/n D371 | Cape Canaveral, SLC-37B | In service | [21] | |
| GPS IIF-10 | USA-262 | 15 July 2015, 15:36 | Atlas V 401, s/n AV-055 | Cape Canaveral, SLC-41 | In service | [17] | |
| GPS IIF-11 | USA-265 | 31 October 2015, 16:13 | Atlas V 401, s/n AV-060 | Cape Canaveral, SLC-41 | In service | [17][22] | |
| GPS IIF-12 | USA-266 | 5 February 2016, 13:38 | Atlas V 401, s/n AV-057 | Cape Canaveral, SLC-41 | In service | [17][23] | |
| (Last update: September 26, 2024) | |||||||
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