USA-239

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USA-239
Navstar-2F.jpg
A Block IIF GPS satellite
Mission type Navigation
Operator US Air Force
COSPAR ID 2012-053A[1]
SATCAT no. 38833[1]
Mission duration 12 years (planned)
Spacecraft properties
Spacecraft GPS SVN-65 (IIF-3)
Spacecraft type GPS Block IIF
Manufacturer Boeing
Launch mass 1,630 kilograms (3,590 lb)[2]
Start of mission
Launch date 4 October 2012, 12:10 (2012-10-04UTC12:10Z) UTC
Rocket Delta IV-M+(4,2), D361[3]
Launch site Cape Canaveral SLC-37B[3]
Contractor ULA
Orbital parameters
Reference system Geocentric
Regime Medium Earth
(Semi-synchronous)
Perigee 20,132 kilometers (12,509 mi)[4]
Apogee 20,231 kilometers (12,571 mi)[4]
Inclination 54.87 degrees[4]
Period 717.96 minutes[4]

USA-239, also known as GPS IIF-3, and GPS SVN-65, is an American navigation satellite which forms part of the Global Positioning System. It was the third of twelve Block IIF satellites to be launched.[2]

Built by Boeing and launched by United Launch Alliance, USA-239 was launched at 12:10 UTC on 4 October 2012, atop a Delta IV carrier rocket, flight number D361, flying in the Medium+(4,2) configuration.[3] The launch took place from Space Launch Complex 37B at the Cape Canaveral Air Force Station,[5] and placed USA-239 directly into medium Earth orbit.[4] The rocket's second stage failed to provide the expected full thrust in all of its three burns due to a leak above the narrow throat portion of the thrust chamber, however the stage had enough propellant margins to put the satellite in the correct orbit.[6]

As of 18 February 2014, USA-232 was in an orbit with a perigee of 20,231 kilometers (12,571 mi), an apogee of 20,132 kilometers (12,509 mi), a period of 717.96 minutes, and 54.87 degrees of inclination to the equator.[4] It is used to broadcast the PRN 24 signal, and operates in slot 1 of plane A of the GPS constellation. The satellite has a design life of 15 years and a mass of 1,630 kilograms (3,590 lb). [2] As of 2014 it remains in service.

References[edit]

  1. ^ a b "Navstar 67". US National Space Science Data Center. Retrieved 18 February 2014. 
  2. ^ a b c Krebs, Gunter. "GPS-2F (Navstar-2F)". Gunter's Space Page. Retrieved 18 February 2014. 
  3. ^ a b c McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 18 February 2014. 
  4. ^ a b c d e f McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 18 February 2014. 
  5. ^ McDowell, Jonathan. "Launch List". Launch Vehicle Database. Jonathan's Space Page. Retrieved 18 February 2014. 
  6. ^ Ray, Justin. "Investigation finds Delta 4 rocket engine issue". Spaceflight Now. Retrieved 18 February 2014.