SMOS

SMOS is an active satellite operated by Centre National d'Etudes Spatiales (CNES)/European Space Agency (ESA) (ESA (European Space Agency)), launched on 2009-11-02 from PKMTR. After 17 years in orbit, it continues to be tracked by global surveillance networks. It orbits in Low Earth Orbit (LEO) at altitudes between 758 km and 760 km with an inclination of 98.4°. It travels at approximately 26,917 km/h (7.48 km/s), completing one full orbit every 100 minutes — that’s roughly 14.40 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 ~25–100 years. Orbital Radar tracks SMOS in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

SMOS orbits at an average altitude of 759 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 SMOS’s average altitude, there are currently 357 active payloads and 2,014 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0179. With an inclination of 98.4°, SMOS passes over latitudes between 98.4°N and 98.4°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. ESA (European Space Agency) operates approximately 93 active satellites in total, of which 10 share a similar altitude band with SMOS.