SPARTAN

SPARTAN is an active satellite operated by Endurosat (Bulgaria), launched on 2021-06-30 from Cape Canaveral Space Force Station, United States on the Transporter-2 launch. It orbits in Low Earth Orbit (LEO) at altitudes between 249 km and 251 km with an inclination of 97.7°. It travels at approximately 27,932 km/h (7.76 km/s), completing one full orbit every 90 minutes — that’s roughly 16.13 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 weeks to months. 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 250 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 78 active payloads and 7 tracked debris or rocket body fragments — notable neighbours include STARLINK-1067, STARLINK-1068, STARLINK-1171. This is a relatively sparse altitude band, containing less than 1% 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 8 active satellites in total.