STSAT 3

STSAT 3 is an active satellite operated by South Korea, launched on 2013-11-21 from OREN on the Dnepr Rideshare 8 launch. After 13 years in orbit, it continues to be tracked by global surveillance networks. It orbits in Low Earth Orbit (LEO) at altitudes between 552 km and 563 km with an inclination of 97.6°. It travels at approximately 27,306 km/h (7.58 km/s), completing one full orbit every 96 minutes — that’s roughly 15.03 orbits per day. Its near-polar, sun-synchronous orbit means it passes over any given point on Earth at approximately the same local solar time, ideal for consistent Earth observation lighting conditions. Its near-circular orbit (eccentricity close to zero) means it maintains a very consistent altitude throughout each revolution. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~3–10 years. Orbital Radar tracks STSAT 3 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

STSAT 3 orbits at an average altitude of 558 km in a sun-synchronous orbit (SSO), a specialised subset of LEO where the orbital plane precesses to maintain a constant angle relative to the Sun. This provides consistent lighting conditions on every pass — essential for Earth observation, weather monitoring and environmental science. Within ±50 km of STSAT 3’s average altitude, there are currently 2,286 active payloads and 413 tracked debris or rocket body fragments — notable neighbours include STARLINK-1184, STARLINK-1276, ONEWEB-0050. This makes it one of the more crowded altitude bands, containing roughly 12.8% of all active satellites. With an inclination of 97.6°, STSAT 3 passes over latitudes between 97.6°N and 97.6°S, providing near-global coverage including the polar regions. Polar and near-polar orbits are used for reconnaissance, weather monitoring and Earth-observation missions that need to image every part of the planet. South Korea operates approximately 54 active satellites in total, of which 14 share a similar altitude band with STSAT 3.