SUNSAT

SUNSAT is an active satellite operated by South Africa, launched on 1999-02-23 from Vandenberg SFB, California. With over 27 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 637 km and 837 km with an inclination of 96.5°. It travels at approximately 26,959 km/h (7.49 km/s), completing one full orbit every 100 minutes — that’s roughly 14.46 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. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~25–100 years. Orbital Radar tracks SUNSAT in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

SUNSAT orbits at an average altitude of 737 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 SUNSAT’s average altitude, there are currently 364 active payloads and 1,876 tracked debris or rocket body fragments — notable neighbours include TERRA, LANDSAT 9. With an inclination of 96.5°, SUNSAT passes over latitudes between 96.5°N and 96.5°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 Africa operates approximately 3 active satellites in total.