NOAA 21

NOAA 21 is an active satellite operated by NOAA (United States), launched on 2022-11-10 from Vandenberg SFB, California. It orbits in Low Earth Orbit (LEO) at altitudes between 826 km and 828 km with an inclination of 98.7°. It travels at approximately 26,790 km/h (7.44 km/s), completing one full orbit every 101 minutes — that’s roughly 14.20 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. It is part of the Weather constellation group. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~100–500 years. Orbital Radar tracks NOAA 21 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

NOAA 21 orbits at an average altitude of 827 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 NOAA 21’s average altitude, there are currently 374 active payloads and 2,243 tracked debris or rocket body fragments — notable neighbours include NOAA 20, ONEWEB-0179, ONEWEB-0455. With an inclination of 98.7°, NOAA 21 passes over latitudes between 98.7°N and 98.7°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. United States operates approximately 12,339 active satellites in total, of which 126 share a similar altitude band with NOAA 21.