Mission typeNavigation
OperatorUS Air Force
COSPAR ID1992-058A[1]
SATCAT no.22108[1]
Mission duration7.5 years (planned)[2]
Spacecraft properties
Spacecraft typeGPS Block IIA[2]
Launch mass1,816 kilograms (4,004 lb)[2]
Start of mission
Launch date9 September 1992, 08:57:00 (1992-09-09UTC08:57Z) UTC
RocketDelta II 7925-9.5, D214[3]
Launch siteCape Canaveral LC-17A[3]
Orbital parameters
Reference systemGeocentric
RegimeMedium Earth
Perigee altitude19,914 kilometres (12,374 mi)[4]
Apogee altitude20,451 kilometres (12,708 mi)[4]
Inclination54.7 degrees[4]
Period717.98 minutes[4]

USA-84, also known as GPS IIA-6, GPS II-15 and GPS SVN-27, is an American navigation satellite which forms part of the Global Positioning System. It was the sixth of nineteen Block IIA GPS satellites to be launched.

USA-84 was launched at 08:57:00 UTC on 9 September 1992, atop a Delta II carrier rocket, flight number D214, flying in the 7925-9.5 configuration.[3] The launch took place from Launch Complex 17A at the Cape Canaveral Air Force Station,[5] and placed USA-84 into a transfer orbit. The satellite raised itself into medium Earth orbit using a Star-37XFP apogee motor.[2]

On 11 October 1992, USA-84 was in an orbit with a perigee of 19,914 kilometres (12,374 mi), an apogee of 20,451 kilometres (12,708 mi), a period of 717.98 minutes, and 54.7 degrees of inclination to the equator.[4] It had PRN 27, and operated in slot 4 of plane A of the GPS constellation.[6] The satellite has a mass of 1,816 kilograms (4,004 lb). It had a design life of 7.5 years,[2] but was in service for twenty years, until its retirement in October 2012.


  1. ^ a b "Navstar 2A-06". US National Space Science Data Center. Retrieved 10 July 2012.
  2. ^ a b c d e f Krebs, Gunter. "GPS-2A (Navstar-2A)". Gunter's Space Page. Retrieved 10 July 2012.
  3. ^ a b c McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 10 July 2012.
  4. ^ a b c d e McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 10 July 2012.
  5. ^ McDowell, Jonathan. "Launch List". Launch Vehicle Database. Jonathan's Space Page. Retrieved 10 July 2012.
  6. ^ Wade, Mark. "Navstar". Encyclopedia Astronautica. Retrieved 10 July 2012.