FORMOSAT 3C

FORMOSAT 3C is an active satellite operated by TWN, launched on 2006-04-15 from Vandenberg SFB, California. With over 20 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 762 km and 812 km with an inclination of 72.0°. It travels at approximately 26,864 km/h (7.46 km/s), completing one full orbit every 101 minutes — that’s roughly 14.31 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~25–100 years. Orbital Radar tracks FORMOSAT 3C in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

FORMOSAT 3C orbits at an average altitude of 787 km in the mid-LEO band, where atmospheric drag is minimal but radiation exposure remains manageable. Objects at this altitude persist for decades to centuries, making debris mitigation critical. This regime is popular for remote sensing constellations and scientific instruments that need stable, long-duration orbits. Within ±50 km of FORMOSAT 3C’s average altitude, there are currently 403 active payloads and 2,222 tracked debris or rocket body fragments — notable neighbours include NOAA 20, ONEWEB-0179, ONEWEB-0455. With an inclination of 72.0°, FORMOSAT 3C passes over latitudes between 72.0°N and 72.0°S, covering most populated land masses in both hemispheres. This mid-inclination band balances global coverage with efficient launch energy requirements. TWN operates approximately 30 active satellites in total, of which 5 share a similar altitude band with FORMOSAT 3C.