SENTINEL-1D

SENTINEL-1D is an active satellite operated by ESA / Copernicus (ESA (European Space Agency)), launched on 2025-11-04 from Guiana Space Centre, Kourou. As a relatively recent addition to the catalogue, its orbital elements are well-characterised. It orbits in Low Earth Orbit (LEO) at altitudes between 695 km and 697 km with an inclination of 98.2°. It travels at approximately 27,037 km/h (7.51 km/s), completing one full orbit every 99 minutes — that’s roughly 14.59 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 ~10–25 years. Orbital Radar tracks SENTINEL-1D in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

SENTINEL-1D orbits at an average altitude of 696 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 SENTINEL-1D’s average altitude, there are currently 275 active payloads and 1,405 tracked debris or rocket body fragments — notable neighbours include TERRA, AQUA, LANDSAT 9. With an inclination of 98.2°, SENTINEL-1D passes over latitudes between 98.2°N and 98.2°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 8 share a similar altitude band with SENTINEL-1D.