NAVSTAR 51 (USA 166) is a payload in MEO orbit, operated by US Air Force Space and Missile Center, launched 2003.
| Orbit class | MEO |
| Inclination | 54.8800° |
| Eccentricity | 0.0148150 |
| Period | 718.0 min |
| Apogee | 20,576 km |
| Perigee | 19,789 km |
| Mean motion | 2.00559479 rev/day |
| RAAN | 214.1790° |
| Arg of perigee | 53.1469° |
| Mean anomaly | 318.2156° |
| B* | 0.0000e+0 |
| Rev at epoch | 17,171 |
1 27663U 03005A 26188.06357402 .00000093 00000-0 00000-0 0 99962 27663 54.8800 214.1790 0148150 53.1469 318.2156 2.00559479171716{
"OBJECT_NAME": "NAVSTAR 51 (USA 166)",
"OBJECT_ID": "2003-005A",
"EPOCH": "2026-07-07T01:31:32.795+00:00",
"MEAN_MOTION": 2.00559479,
"ECCENTRICITY": 0.014815,
"INCLINATION": 54.88,
"RA_OF_ASC_NODE": 214.179,
"ARG_OF_PERICENTER": 53.1469,
"MEAN_ANOMALY": 318.2156,
"EPHEMERIS_TYPE": 0,
"CLASSIFICATION_TYPE": "U",
"NORAD_CAT_ID": 27663,
"REV_AT_EPOCH": 17171,
"BSTAR": 0,
"MEAN_MOTION_DOT": 9.3e-7,
"MEAN_MOTION_DDOT": 0
}Reconstructed from CelesTrak OMM mean-elements (element-set number is a placeholder). TLE/OMM data is approximate. Not for operational use or collision avoidance.
| Name | NAVSTAR 51 (USA 166) |
| Operator | US Air Force Space and Missile CenterHIGHvia GCAT — Jonathan McDowell's General Catalog⚠ sources disagree |
| Country | |
| Launch date | |
| Launch mass (kg) | 1077HIGH |
//Orbital data is approximate and not for operational use. Last ingested from CelesTrak on Jul 7, 2026.
| Mission purpose | — |
| Object class |
| Orbital regime |
| Status |