OBJECT J

OBJECT J (NORAD ID 49403) is a space object catalogued under Japan, launched on 2021-11-09 from Uchinoura, Japan on the RAISE-2 launch. It orbits in Low Earth Orbit (LEO) at altitudes between 302 km and 310 km with an inclination of 97.3°. It travels at approximately 27,815 km/h (7.73 km/s), completing one full orbit every 91 minutes — that’s roughly 15.89 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 OBJECT J in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

OBJECT J orbits at an average altitude of 306 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 OBJECT J’s average altitude, there are currently 522 active payloads and 14 tracked debris or rocket body fragments — notable neighbours include STARLINK-1067, STARLINK-1068, STARLINK-1171. With an inclination of 97.3°, OBJECT J passes over latitudes between 97.3°N and 97.3°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 2 share a similar altitude band with OBJECT J.