| USA-239 | |
| Mission Type: | Navigation |
| Operator: | US Air Force |
| Cospar Id: | 2012-053A[1] |
| Satcat: | 38833 |
| Mission Duration: | 12 years (planned) |
| Spacecraft: | GPS SVN-65 (IIF-3) |
| Spacecraft Type: | GPS Block IIF |
| Manufacturer: | Boeing |
| Launch Date: | UTC |
| Launch Rocket: | D361 |
| Launch Site: | Cape Canaveral SLC-37B |
| Launch Contractor: | ULA |
| Orbit Reference: | Geocentric |
| Orbit Regime: | Medium Earth (Semi-synchronous) |
| Orbit Apoapsis: | 20231km (12,571miles) |
| Orbit Periapsis: | 20132km (12,509miles) |
| Orbit Inclination: | 54.87 degrees |
| Orbit Period: | 717.96 minutes |
| Apsis: | gee |
USA-239, also known as GPS IIF-3, GPS SVN-65, and Navstar-67 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.
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.[2] The launch took place from Space Launch Complex 37B at the Cape Canaveral Air Force Station,[3] and placed USA-239 directly into medium Earth orbit. 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.[4]
As of 18 February 2014, USA-239 was in an orbit with a perigee of 20231km (12,571miles), an apogee of 20132km (12,509miles), a period of 717.96 minutes, and 54.87 degrees of inclination to the equator.[5] 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 .[6] As of 2019 it remains in service.