XRISM

XRISM is an active satellite operated by Japan, launched on 2023-09-06 from TNSTA. It orbits in Low Earth Orbit (LEO) at altitudes between 523 km and 534 km with an inclination of 31.0°. It travels at approximately 27,363 km/h (7.60 km/s), completing one full orbit every 95 minutes — that’s roughly 15.12 orbits per day. 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 XRISM in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

XRISM orbits at an average altitude of 529 km in the core of Low Earth Orbit, the most heavily utilised altitude band. The balance of moderate drag (limiting debris accumulation) and short signal path (enabling low-latency links and high-resolution imaging) makes this regime the default for most commercial and government missions. Within ±50 km of XRISM’s average altitude, there are currently 6,772 active payloads and 287 tracked debris or rocket body fragments — notable neighbours include STARLINK-1184, STARLINK-1231, STARLINK-1276. This makes it one of the more crowded altitude bands, containing roughly 38.9% of all active satellites. With an inclination of 31.0°, XRISM passes over latitudes between 31.0°N and 31.0°S, covering the tropical and temperate zones where most of the world’s population resides. Low-to-mid inclination orbits are efficient to reach from equatorial and mid-latitude launch sites. Japan operates approximately 189 active satellites in total, of which 47 share a similar altitude band with XRISM.