XRISM

XRISM is an active satellite operated by JAXA / ISAS/JAXA (Japan), launched on 2023-09-06 from Tanegashima Space Center, Japan on the XRISM/SLIM launch. It orbits in Low Earth Orbit (LEO) at altitudes between 522 km and 532 km with an inclination of 31.0°. It travels at approximately 27,366 km/h (7.60 km/s), completing one full orbit every 95 minutes — that’s roughly 15.13 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 527 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 5,212 active payloads and 304 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 27.9% 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 208 active satellites in total, of which 55 share a similar altitude band with XRISM.