NAVSTAR 55 (USA 178) is a payload in MEO orbit, operated by US Air Force Space and Missile Center, launched 2004.
| Orbit class | MEO |
| Inclination | 54.8759° |
| Eccentricity | 0.0159588 |
| Period | 718.0 min |
| Apogee | 20,607 km |
| Perigee | 19,759 km |
| Mean motion | 2.00557801 rev/day |
| RAAN | 85.9756° |
| Arg of perigee | 302.4989° |
| Mean anomaly | 284.7450° |
| B* | 0.0000e+0 |
| Rev at epoch | 16,140 |
1 28361U 04023A 26186.40522939 -.00000014 00000-0 00000-0 0 99922 28361 54.8759 85.9756 0159588 302.4989 284.7450 2.00557801161401{
"OBJECT_NAME": "NAVSTAR 55 (USA 178)",
"OBJECT_ID": "2004-023A",
"EPOCH": "2026-07-05T09:43:31.819+00:00",
"MEAN_MOTION": 2.00557801,
"ECCENTRICITY": 0.0159588,
"INCLINATION": 54.8759,
"RA_OF_ASC_NODE": 85.9756,
"ARG_OF_PERICENTER": 302.4989,
"MEAN_ANOMALY": 284.745,
"EPHEMERIS_TYPE": 0,
"CLASSIFICATION_TYPE": "U",
"NORAD_CAT_ID": 28361,
"REV_AT_EPOCH": 16140,
"BSTAR": 0,
"MEAN_MOTION_DOT": -1.4e-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 55 (USA 178) |
| 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 |