ST5-A

ST5-A is an active satellite operated by United States, launched on 2006-03-22 from WRAS. With over 20 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 297 km and 2,884 km with an inclination of 105.5°. It travels at approximately 25,473 km/h (7.08 km/s), completing one full orbit every 118 minutes — that’s roughly 12.20 orbits per day. Its orbital eccentricity of 0.1625 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is thousands of years. Orbital Radar tracks ST5-A in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

ST5-A orbits at an average altitude of 1,591 km in Medium Earth Orbit, the region between LEO and GEO (2,000–35,786 km). MEO’s higher altitude gives each satellite a much larger ground footprint than LEO, meaning fewer spacecraft are needed for global coverage — but signal latency is higher and radiation from the Van Allen belts is a significant design constraint. Within ±50 km of ST5-A’s average altitude, there are currently 34 active payloads and 214 tracked debris or rocket body fragments. This is a relatively sparse altitude band, containing less than 1% of all active satellites. With an inclination of 105.5°, ST5-A passes over latitudes between 105.5°N and 105.5°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.