NEMO-HD

NEMO-HD is an active satellite operated by Center of Excellence for Space Sciences and Technologies (SPACE-SI) (SVN), launched on 2020-09-03 from Guiana Space Centre, French Guiana on the SSMS launch. It orbits in Low Earth Orbit (LEO) at altitudes between 425 km and 426 km with an inclination of 97.2°. It travels at approximately 27,569 km/h (7.66 km/s), completing one full orbit every 93 minutes — that’s roughly 15.47 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 ~1–3 years. Orbital Radar tracks NEMO-HD in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

NEMO-HD orbits at an average altitude of 426 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 NEMO-HD’s average altitude, there are currently 6,973 active payloads and 121 tracked debris or rocket body fragments — notable neighbours include ISS (ZARYA), STARLINK-1017, STARLINK-1039. This makes it one of the more crowded altitude bands, containing roughly 36.8% of all active satellites. With an inclination of 97.2°, NEMO-HD passes over latitudes between 97.2°N and 97.2°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. SVN operates approximately 2 active satellites in total.