SPARTAN

SPARTAN is an active satellite operated by Endurosat (Bulgaria), launched on 2021-06-30 from Cape Canaveral, Florida. It orbits in Low Earth Orbit (LEO) at altitudes between 330 km and 331 km with an inclination of 97.7°. It travels at approximately 27,764 km/h (7.71 km/s), completing one full orbit every 91 minutes — that’s roughly 15.80 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 months to ~1 year. Orbital Radar tracks SPARTAN in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

SPARTAN orbits at an average altitude of 331 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 SPARTAN’s average altitude, there are currently 1,077 active payloads and 29 tracked debris or rocket body fragments — notable neighbours include STARLINK-1036, STARLINK-1043, STARLINK-1048. This makes it one of the more crowded altitude bands, containing roughly 6.2% of all active satellites. With an inclination of 97.7°, SPARTAN passes over latitudes between 97.7°N and 97.7°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. Bulgaria operates approximately 6 active satellites in total.