SOLRAD 11A

SOLRAD 11A is an active satellite operated by NRL (United States), launched on 1976-03-15 from Cape Canaveral Space Force Station, United States on the LES 8 launch. After more than 50 years in orbit, it is one of the longest-surviving objects in the space catalogue. It orbits in Medium Earth Orbit (MEO) at altitudes between 117,698 km and 119,250 km with an inclination of 14.7°. It travels at approximately 6,433 km/h (1.79 km/s), completing one full orbit every 122.0 hours — that’s roughly 0.20 orbits per day. At geostationary altitude, there is no meaningful atmospheric drag — this object will remain in orbit indefinitely unless actively deorbited. Orbital Radar tracks SOLRAD 11A in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

SOLRAD 11A orbits at an average altitude of 118,474 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. With an inclination of 14.7°, SOLRAD 11A passes over latitudes between 14.7°N and 14.7°S, concentrating coverage over equatorial and near-equatorial regions. Low-inclination orbits maximise revisit rates over specific tropical zones. United States operates approximately 13,279 active satellites in total.