ISO

ISO is an active satellite operated by ESA (European Space Agency), launched on 1995-11-17 from Guiana Space Centre, Kourou. With over 31 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Highly Elliptical Orbit (HEO) at altitudes between 493 km and 70,015 km with an inclination of 1.2°. It travels at approximately 11,140 km/h (3.09 km/s), completing one full orbit every 23 hours 29 minutes — that’s roughly 1.02 orbits per day. Its orbital eccentricity of 0.8351 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. At geostationary altitude, there is no meaningful atmospheric drag — this object will remain in orbit indefinitely unless actively deorbited. Orbital Radar tracks ISO in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

ISO follows a Highly Elliptical Orbit, sweeping between 493 km (perigee) and 70,015 km (apogee). It spends most of its 23 hours 29 minutes orbital period near apogee, effectively loitering over a region of interest before rapidly sweeping through perigee — a profile used for high-latitude communications (Molniya orbits), early-warning systems and magnetospheric science. Within ±50 km of ISO’s average altitude, there are currently 3 active payloads and 14 tracked debris or rocket body fragments. This is a relatively sparse altitude band, containing less than 1% of all active satellites. With an inclination of 1.2°, ISO passes over latitudes between 1.2°N and 1.2°S, concentrating coverage over equatorial and near-equatorial regions. Low-inclination orbits maximise revisit rates over specific tropical zones. ESA (European Space Agency) operates approximately 93 active satellites in total.