DMSP 5D-3 F16 (USA 172)

DMSP 5D-3 F16 (USA 172) is an active satellite operated by DoD/NOAA (United States), launched on 2003-10-18 from Vandenberg SFB, California. With over 23 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 838 km and 850 km with an inclination of 99.0°. It travels at approximately 26,758 km/h (7.43 km/s), completing one full orbit every 102 minutes — that’s roughly 14.14 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 ~100–500 years. Orbital Radar tracks DMSP 5D-3 F16 (USA 172) in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

DMSP 5D-3 F16 (USA 172) orbits at an average altitude of 844 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 DMSP 5D-3 F16 (USA 172)’s average altitude, there are currently 245 active payloads and 2,115 tracked debris or rocket body fragments — notable neighbours include NOAA 20, ONEWEB-0179, ONEWEB-0455. With an inclination of 99.0°, DMSP 5D-3 F16 (USA 172) passes over latitudes between 99.0°N and 99.0°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 12,360 active satellites in total, of which 47 share a similar altitude band with DMSP 5D-3 F16 (USA 172).