NAVSTAR 55 (USA 178)

NavigationMilitaryMEOUnited States

NAVSTAR 55 (USA 178) is a navigation satellite, with ownership listed as United States in CelesTrak's catalogue, currently in medium Earth orbit near 19,767 km. It completes one orbit of Earth roughly every 718 minutes at an inclination of 55.0°. It was launched in 2004. Track its live position and see when it passes over your location on azmth.

Orbital data

NORAD ID: 28361
COSPAR ID: 2004-023A
Type: Navigation
Orbit: MEO
Perigee (lowest): 19,767 km
Apogee (highest): 20,612 km
Inclination: 54.96°
Orbital period: 718 min
Launch year: 2004
Owner (CelesTrak): United States

Orbital data updated: 2026-10-18 · from CelesTrak, refreshed every 2 hours.

Who operates it

United StatesLIVEMission ended 2 Mar 2020

Navigation

GCAT lists it as GPS IIR-12.

Independent assessment

GCAT classes it as a military satellite for navigation and records its mission as ended on 2 Mar 2020 (17 Oct 2026).

Data: GCAT · CC BY 4.0 Class, mission and status adapted from GCAT by Jonathan McDowell, CC BY 4.0, data update 17 Oct 2026.

Military satellites, counted and explained →

About MEO orbit

Medium Earth Orbit. Between 2,000 and 35,786 km. Home to navigation constellations like GPS (~20,200 km), Galileo, and BeiDou. Orbital period 2 to 24 hours.