PRISMA

PRISMA is an active satellite operated by Italian Space Agency (Italy), launched on 2019-03-22 from Guiana Space Centre, Kourou. It orbits in Low Earth Orbit (LEO) at altitudes between 617 km and 619 km with an inclination of 97.9°. It travels at approximately 27,187 km/h (7.55 km/s), completing one full orbit every 97 minutes — that’s roughly 14.84 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 PRISMA in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

PRISMA orbits at an average altitude of 618 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 PRISMA’s average altitude, there are currently 1,547 active payloads and 748 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0050, STARLINK-3090, STARLINK-3077. This makes it one of the more crowded altitude bands, containing roughly 8.9% of all active satellites. With an inclination of 97.9°, PRISMA passes over latitudes between 97.9°N and 97.9°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. Italy operates approximately 88 active satellites in total, of which 31 share a similar altitude band with PRISMA.