Key statistics
Satellite NAVSTAR 51 (USA 166) at a glance.
Uptime
8255
Days in orbit
Revolutions
≈ 2.0
Per day
Orbit
MEO
Medium Earth Orbit
Inclination
55.0
Latest
Satellite identification and parameters
Extended collection of information and parameters for NAVSTAR 51 (USA 166).
Object identification
Identified? True
Debris? False
Object name: NAVSTAR 51 (USA 166)
International designator: 2003-005A
Object number (NORAD): 27663
Object ID (CCSDS): 27663
Country: UNITED STATES OF AMERICA (US)
Current information (Y/N): Y
RCS size: LARGE
Orbital parameters
Period: 718.026 minutes
Inclination: 54.9544 deg
SMA: 26561.566 km
Apoapsis: 20565.579 km
Periapsis: 19801.283 km
RAAN: 226.3337 deg
Eccentricy: 0.01438725
Argument of periapsis: 50.5641 deg
Mean anomaly: 134.669 deg
Mean motion: 2.00549806 rev/day
Mean motion (dot): 0.0000005 rev/day2
B* drag term: 0.0 1/REarth
Two-line elements (TLE)
Creation date: Sept. 4, 2025, 10:13 a.m.
Reference frame: TEME
Reference center: EARTH
Epoch: Sept. 4, 2025, 4:24 a.m. UTC
TLE line 0: 0 NAVSTAR 51 (USA 166)
TLE line 1: 1 27663U 03005A 25247.18377992 .00000050 00000-0 00000-0 0 9993
TLE line 2: 2 27663 54.9544 226.3337 0143872 50.5641 134.6690 2.00549806165576
Live tracking on map
Real-time ground track for satellite NAVSTAR 51 (USA 166).
In-orbit conjunctions
There are no conjunctions computed for NAVSTAR 51 (USA 166), at the moment. Check back to stay up to date, as we update our databases every day.
Go to all conjunctionsAssociated space launch
USA-166, also known as GPS IIR-8 and GPS SVN-56, is an American navigation satellite which forms part of the Global Positioning System. It was the eighth Block IIR GPS satellite to be launched, out of thirteen in the original configuration, and twenty one overall.
NAVSTAR 51 (USA 166) was lifted into orbit during the mission ‘Delta II | GPS IIR-8’, on board a Delta II space rocket.
The launch took place on Jan. 29, 2003, 6:06 p.m. from Space Launch Complex 17B.
For more information about the launch, click the button.
Delta II | GPS IIR-8
Agency: N/A
Status: Launch Successful
Launch date: Jan. 29, 2003, 6:06 p.m. UTC
Rocket: Delta II
Launch pad: Space Launch Complex 17B
Location: Cape Canaveral SFS, FL, USA
...
Latest news about this satellite
There are no fresh news available about this satellite. Check back as we update our databases every day.
Newsletter sign-up
Weekly statistics, charts and insights to help you stay on top of the space industry.
