USA-242

Summary

USA-242
Navstar-2F.jpg
Artist's impression of a GPS IIF satellite
Mission typeNavigation
OperatorUS Air Force
COSPAR ID2013-023A
SATCAT no.39166
Mission duration12 years (planned)
Spacecraft properties
SpacecraftGPS SVN-66 (IIF-4)
Spacecraft typeGPS Block IIF
ManufacturerBoeing
Launch mass1,630 kilograms (3,590 lb)[1]
Start of mission
Launch date15 May 2013, 21:38 (2013-05-15UTC21:38Z) UTC
RocketAtlas V 401, AV-039
Launch siteCape Canaveral SLC-41
ContractorULA
Orbital parameters
Reference systemGeocentric
RegimeMedium Earth
(Semi-synchronous)
Perigee altitude20,459 kilometers (12,713 mi)[2]
Apogee altitude20,459 kilometers (12,713 mi)[2]
Inclination55 degrees[2]
Period12 hours
EpochTarget
 

USA-242, also known as GPS IIF-4, GPS IIF SV-5, Navstar-68 and Vega,[3] is an American navigation satellite which was launched on 15 May 2013 and became operational on 21 June 2013.[4] The fourth Block IIF GPS satellite, it forms part of the Global Positioning System.

USA-242 is a 1,630-kilogram (3,590 lb) spacecraft, built by Boeing with a design life of 15 years.[1] It operates from a semi-synchronous medium Earth orbit, at an altitude of 20,459 kilometers (12,713 mi) an inclination of 55 degrees,[2] in slot 5 of plane C of the GPS constellation.[5] The new satellite was originally intended to replace the seventeen-year-old USA-117 satellite,[6] but currently both USA-117 (SVN-33) and USA-242 (SVN-66) are in active use.[7] USA-242 broadcasts its navigation signals using the PRN-27 signal modulation.

United Launch Alliance conducted the launch of GPS IIF-4, using an Atlas V 401 carrier rocket. Launch took place from Space Launch Complex 41 at the Cape Canaveral Air Force Station, with liftoff occurring at 21:38 UTC on 15 May 2013, the beginning of an 18-minute launch window. The launch marked the first time since 1985 that a GPS satellite had launched on an Atlas rocket, or indeed any rocket other than a Delta.[6]

References

  1. ^ a b Krebs, Gunter. "GPS-2F (Navstar-2F)". Gunter's Space Page. Retrieved 15 May 2013.
  2. ^ a b c d "GPS IIF-4 Atlas V Mission Overview" (PDF). United Launch Alliance. Archived from the original (PDF) on 16 September 2013. Retrieved 15 May 2013.
  3. ^ McDowell, Jonathan. "Issue 679 (draft)". Jonathan's Space Report. Retrieved 16 May 2013.
  4. ^ "NANU 2013035". United States Coast Guard. Retrieved 25 June 2013.
  5. ^ Ray, Justin. "Mission Status Center". Spaceflight Now. Retrieved 15 May 2013.
  6. ^ a b Graham, William (15 May 2013). "ULA Atlas V successfully [sic] deploys new GPS satellite". NASASpaceflight.com. Retrieved 16 May 2013.
  7. ^ "GPS Constellation Status". United States Coast Guard. Retrieved 25 June 2013.