USA-47

USA-47, also known as GPS II-4 and GPS SVN-19, was an American navigation satellite which formed part of the Global Positioning System. It was the fourth of nine Block II GPS satellites to be launched, which were the first operational GPS satellites to fly.

USA-47 was launched at 09:31:01 UTC on 21 October 1989, atop a Delta II carrier rocket, flight number D188, flying in the 6925 configuration. The launch took place from Launch Complex 17A at the Cape Canaveral Air Force Station, and placed USA-47 into a transfer orbit. The satellite raised itself into medium Earth orbit using a Star-37XFP apogee motor.

On 21 November 1989, USA-47 was in an orbit with a perigee of 20081 km, an apogee of 20280 km, a period of 717.9 minutes, and 54.7 degrees of inclination to the equator. It operated in slot 5 of plane A of the GPS constellation. The satellite had a mass of 840 kg, and generated 710 watts of power. It had a design life of 7.5 years, and ceased operations on 11 September 2001.