Mission type Navigation COSPAR ID 1991-047A Mission duration 7.5 years (planned) Inclination 55.1° Period 12 hours Launch mass 1,816 kg Rocket Delta II | Operator US Air Force SATCAT no. 21552 Spacecraft type GPS Block IIA Inclination 55.1° Launch mass 1,816 kg Launch date 4 July 1991 | |
USA-71, also known as GPS IIA-2, GPS II-11 and GPS SVN-24, is an American navigation satellite which forms part of the Global Positioning System. It was the second of nineteen Block IIA GPS satellites to be launched.
USA-71 was launched at 02:32:00 UTC on 4 July 1991, atop a Delta II carrier rocket, flight number D206, flying in the 7925-9.5 configuration. The rocket launched from Launch Complex 17A at the Cape Canaveral Air Force Station, and placed USA-71 into a transfer orbit. The satellite raised itself into medium Earth orbit using a Star-37XFP apogee motor.
On 14 August 1991, USA-71 was in an orbit with a perigee of 20,085 kilometres (12,480 mi), an apogee of 20,274 kilometres (12,598 mi), a period of 717.86 minutes, and 55.1 degrees of inclination to the equator. It has PRN 24, and operated in slot 1 of plane D of the GPS constellation until it was removed from service in September 2009. It was subsequently relocated, was operational again, briefly covering slot 2 in 2011, before being deactivated in November after USA-232 replaced it. It began transmitting navigation signals again in March 2012; however, it is not currently part of the operational GPS constellation. The satellite has a mass of 1,816 kilograms (4,004 lb), and a design life of 7.5 years.