FLEX

FLEX is an active satellite operated by ESA (European Space Agency), launched on 2026-09-15 from Guiana Space Centre, French Guiana on the Sentinel-3C/Flex launch. As a relatively recent addition to the catalogue, its orbital elements are well-characterised. It orbits in Low Earth Orbit (LEO) at altitudes between 812 km and 815 km with an inclination of 98.6°. It travels at approximately 26,815 km/h (7.45 km/s), completing one full orbit every 101 minutes — that’s roughly 14.23 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 FLEX in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

FLEX orbits at an average altitude of 814 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 FLEX’s average altitude, there are currently 454 active payloads and 2,517 tracked debris or rocket body fragments — notable neighbours include NOAA 20, ONEWEB-0455. With an inclination of 98.6°, FLEX passes over latitudes between 98.6°N and 98.6°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 95 active satellites in total, of which 10 share a similar altitude band with FLEX.