OPS 5118

OPS 5118, also known as Navstar 6, GPS I-6 and GPS SVN-6, was an American navigation satellite launched in 1980 as part of the Global Positioning System development programme. It was the sixth of eleven Block I GPS satellites to be launched.

OPS 5118 was launched at 22:00 UTC on 26 April 1980, atop an Atlas E/F carrier rocket with an SGS-1 upper stage. The Atlas used had the serial number 34F, and was originally built as an Atlas F. The launch took place from Space Launch Complex 3E at Vandenberg Air Force Base, and placed OPS 5118 into a transfer orbit. The satellite raised itself into medium Earth orbit using a Star-27 apogee motor.

By 27 May 1980, OPS 5118 had been raised to an orbit with a perigee of 20006 km, an apogee of 20357 km, a period of 717.94 minutes, and 62.8 degrees of inclination to the equator. The satellite had a design life of 5 years and a mass of 758 kg. It broadcast the PRN 09 signal in the GPS demonstration constellation, and was retired from service on 6 March 1991.