What is LEO?
Low Earth Orbit (LEO) is the region of space between 160 and 2,000 km above Earth's surface. It is the most densely populated orbital shell, hosting approximately 55% of all active satellites. Most LEO broadband constellations cluster around 550 km (Starlink) or 1,200 km (OneWeb).
Key characteristics
A satellite at 550 km completes one orbit in roughly 95 minutes at 7.6 km/s, covering the sky rapidly relative to any fixed ground point. This motion requires either steerable antennas or, more commonly, a large constellation to ensure continuous coverage. Round-trip latency ranges from 15 to 70 ms — comparable to terrestrial broadband — compared to 550+ ms for GEO satellites.
Why LEO matters for connectivity
LEO's proximity to Earth reduces free-space path loss and latency, enabling applications that were impossible over GEO: real-time gaming, VoIP, financial trading, and low-latency enterprise connectivity in remote areas. SpaceX Starlink operates 10,000+ satellites in LEO, serving over 10 million customers across 150 countries as of 2026.
Trade-offs
The main drawback is coverage geometry: a single LEO satellite sees a ground footprint of only a few hundred kilometres, and passes over any fixed point for just 5–10 minutes. Global coverage therefore requires constellations of hundreds to thousands of satellites — and the associated costs, orbital coordination, and debris management challenges.
Key LEO operators
Starlink (SpaceX, ~550 km), Eutelsat OneWeb (~1,200 km), Iridium (~781 km, 66 satellites), Amazon Kuiper (planned ~630 km), Telesat Lightspeed (~1,000 km).