PACE

PACE is an active satellite operated by VKI / NCKU (TWN), launched on 2014-06-19 from Yasny / Dombarovsky, Russia on the Dnepr Rideshare 9 launch. After 12 years in orbit, it continues to be tracked by global surveillance networks. It orbits in Low Earth Orbit (LEO) at altitudes between 528 km and 535 km with an inclination of 98.1°. It travels at approximately 27,357 km/h (7.60 km/s), completing one full orbit every 95 minutes — that’s roughly 15.12 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 PACE in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

PACE orbits at an average altitude of 532 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 PACE’s average altitude, there are currently 5,007 active payloads and 331 tracked debris or rocket body fragments — notable neighbours include STARLINK-1184, STARLINK-1276, STARLINK-1451. This makes it one of the more crowded altitude bands, containing roughly 26.8% of all active satellites. With an inclination of 98.1°, PACE passes over latitudes between 98.1°N and 98.1°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. TWN operates approximately 32 active satellites in total, of which 16 share a similar altitude band with PACE.