What is MEO?
Medium Earth Orbit (MEO) encompasses the region between 2,000 km and 35,786 km altitude. It sits between the radiation-intensive Van Allen belts and below the geostationary ring. MEO offers a compromise between LEO's low latency and GEO's large coverage footprint, with latency typically in the 70–150 ms range.
Primary uses
MEO is the home of global navigation satellite systems (GNSS). GPS satellites orbit at 20,200 km with a 12-hour period; Europe's Galileo operates at 23,222 km with a 14-hour period; Russia's GLONASS and China's BeiDou use similar shells. Each system requires about 24–30 satellites for global coverage — far fewer than a LEO constellation.
MEO for broadband: O3b mPOWER
SES operates O3b mPOWER at 8,063 km, a non-geostationary MEO constellation providing terabits of broadband capacity with latency around 130 ms. Launched from 2024 onwards, it targets cellular backhaul, maritime, and government customers that need higher throughput than GEO and lower latency than traditional GEO without the complexity of managing a LEO mega-constellation.
Radiation environment
MEO passes through or sits above the Van Allen radiation belts, requiring radiation-hardened electronics. This increases satellite manufacturing cost compared to LEO but results in longer satellite lifetimes (10–15 years vs. 5–7 for LEO).