RESURS O1-N4

RESURS O1-N4 is an active satellite operated by Russia (CIS), launched on 1998-07-10 from Baikonur, Kazakhstan. With over 28 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 806 km and 810 km with an inclination of 98.9°. It travels at approximately 26,825 km/h (7.45 km/s), completing one full orbit every 101 minutes — that’s roughly 14.25 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 ~100–500 years. Orbital Radar tracks RESURS O1-N4 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

RESURS O1-N4 orbits at an average altitude of 808 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 RESURS O1-N4’s average altitude, there are currently 439 active payloads and 2,320 tracked debris or rocket body fragments — notable neighbours include NOAA 20, ONEWEB-0179, ONEWEB-0455. With an inclination of 98.9°, RESURS O1-N4 passes over latitudes between 98.9°N and 98.9°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. Russia (CIS) operates approximately 1,286 active satellites in total, of which 86 share a similar altitude band with RESURS O1-N4.