HELIOS 1A

HELIOS 1A is an active satellite operated by France, launched on 1995-07-07 from Guiana Space Centre, Kourou. With over 31 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 540 km and 558 km with an inclination of 98.2°. It travels at approximately 27,322 km/h (7.59 km/s), completing one full orbit every 96 minutes — that’s roughly 15.06 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. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~3–10 years. Orbital Radar tracks HELIOS 1A in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

HELIOS 1A orbits at an average altitude of 549 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 HELIOS 1A’s average altitude, there are currently 3,455 active payloads and 358 tracked debris or rocket body fragments — notable neighbours include STARLINK-1184, STARLINK-1276, ONEWEB-0050. This makes it one of the more crowded altitude bands, containing roughly 19.8% of all active satellites. With an inclination of 98.2°, HELIOS 1A 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. France operates approximately 115 active satellites in total, of which 29 share a similar altitude band with HELIOS 1A.