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SBIRS GEO-4 (USA 273) — Live Satellite Tracking (NORAD 41937)
Track SBIRS GEO-4 (USA 273) (NORAD catalog number 41937) live on the WatchSat interactive 3D globe above. Its position is propagated in real time from the latest CelesTrak two-line element set using the SGP4/SDP4 orbital model — the same math professional trackers run. It has been on orbit since 2017, launched on the 4th orbital launch of that year (COSPAR designation 2017-004A). As of this element set it had completed roughly 3,542 revolutions of Earth.
Moving at about 3.07 km/s, SBIRS GEO-4 (USA 273) sits in the geostationary belt roughly 35,786 km above the equator, where its 24.1-hour orbit matches Earth's rotation — seen from the ground it stays parked over the same longitude around the clock. The orbit is essentially circular (eccentricity 0.0002). Its near-equatorial 2.4° inclination keeps it above the tropics at all times. Its orbital plane crosses the equator northbound at right ascension 45.2°.
Orbital elements
| Orbit regime | geostationary/geosynchronous orbit (GEO) |
|---|---|
| Perigee × apogee altitude | ~35,953 km × 35,971 km |
| Inclination | 2.40° |
| Orbital period | 1444.7 min (1.00 rev/day) |
| Eccentricity | 0.00022 |
| Element set epoch | 2026-09-07 |
| COSPAR designation | 2017-004A |
| NORAD catalog number | 41937 |
This page's orbital elements come from the CelesTrak catalog of 2026-09-08. The live 3D view above fetches its own current CelesTrak data when the page opens, through an edge cache that refreshes roughly every 30 minutes.
About the Other Active Satellites group
SBIRS GEO-4 (USA 273) is one of 4,471 active satellites in WatchSat's general catalog — the broad population of Earth-observation, communications, science, amateur-radio and technology spacecraft outside the giant broadband constellations. Browse all other active satellites live in 3D.
Can you see SBIRS GEO-4 (USA 273) from the ground?
Not with the naked eye. At its altitude SBIRS GEO-4 (USA 273) is far beyond unaided visibility — following satellites this high takes a telescope and good timing. You can still track it precisely in the live 3D view above, or check pass predictions for your location.
Related satellites
Nearest catalog neighbors of SBIRS GEO-4 (USA 273) in the Other Active Satellites group — usually craft from the same or adjacent launches:
- HISPASAT 36W-1 (NORAD 41942)
- TELKOM 3S (NORAD 41944)
- INTELSAT 32E (IS-32E) (NORAD 41945)
- IRIDIUM 111 (NORAD 41926)
- CARTOSAT-2D (NORAD 41948)
- IRIDIUM 112 (NORAD 41925)
Browse the Other Active Satellites directory or the full satellite directory · What is a TLE? · WatchSat live globe