PROITERES

PROITERES is an active satellite operated by Japan, launched on 2012-09-09 from SRI. After 14 years in orbit, it continues to be tracked by global surveillance networks. It orbits in Low Earth Orbit (LEO) at altitudes between 613 km and 630 km with an inclination of 98.2°. It travels at approximately 27,180 km/h (7.55 km/s), completing one full orbit every 97 minutes — that’s roughly 14.83 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 ~10–25 years. Orbital Radar tracks PROITERES in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

PROITERES orbits at an average altitude of 622 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 PROITERES’s average altitude, there are currently 1,528 active payloads and 784 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0050, STARLINK-3090, STARLINK-3077. This makes it one of the more crowded altitude bands, containing roughly 8.8% of all active satellites. With an inclination of 98.2°, PROITERES passes over latitudes between 98.2°N and 98.2°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. Japan operates approximately 189 active satellites in total, of which 27 share a similar altitude band with PROITERES.