OPS 9794

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OPS 9794
Mission typeNavigation
OperatorUS Air Force
COSPAR ID1983-072A[1]
SATCAT no.14189[1]
Mission duration5 years (planned)
10 years (achieved)
Spacecraft properties
Spacecraft typeGPS Block I
Launch mass759 kilograms (1,673 lb)[2]
Start of mission
Launch date14 July 1983, 10:21 (1983-07-14UTC10:21Z) UTC
RocketAtlas E/F SGS-2, 75E[3]
Launch siteVandenberg SLC-3W[3]
End of mission
Deactivated4 May 1993 (1993-05-05)
Orbital parameters
Reference systemGeocentric
RegimeMedium Earth
Perigee altitude19,924 kilometres (12,380 mi)[4]
Apogee altitude20,439 kilometres (12,700 mi)[4]
Inclination62.8 degrees[4]
Period717.96 minutes[4]

OPS 9794, also known as Navstar 8, GPS I-8 and GPS SVN-8, was an American navigation satellite launched in 1983 as part of the Global Positioning System development program. It was the eighth of eleven Block I GPS satellites to be launched.[2]

OPS 9794 was launched at 10:21 UTC on 14 July 1983, atop an Atlas E/F carrier rocket with an SGS-2 upper stage. The Atlas used had the serial number 75E, and was originally built as an Atlas E.[3] The launch took place from Space Launch Complex 3W at Vandenberg Air Force Base,[5] and placed OPS 9794 into a transfer orbit. The satellite raised itself into medium Earth orbit using a Star-27 apogee motor.[2]

By 14 August 1983, OPS 9794 had been raised to an orbit with a perigee of 19,924 kilometres (12,380 mi), an apogee of 20,439 kilometres (12,700 mi), a period of 717.96 minutes, and 62.8 degrees of inclination to the equator.[4] The satellite had a design life of 5 years and a mass of 758 kilograms (1,671 lb).[2] It broadcast the PRN 11 signal in the GPS demonstration constellation, and was retired from service on 4 May 1993.


  1. ^ a b "Navstar 8". US National Space Science Data Center. Retrieved 25 June 2012.
  2. ^ a b c d e Krebs, Gunter. "GPS (Navstar)". Gunter's Space Page. Retrieved 12 July 2012.
  3. ^ a b c McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 12 July 2012.
  4. ^ a b c d e McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 12 July 2012.
  5. ^ McDowell, Jonathan. "Launch List". Launch Vehicle Database. Jonathan's Space Page. Retrieved 12 July 2012.