LEO Satellites Explained: Low Earth Orbit and Broadband
LEO satellites orbit ~160 to 2,000 km up. Here is why low Earth orbit powers low-latency broadband, why it needs huge constellations, and the tradeoffs.
Satellites & Communications
How satellites and satellite communications actually work: orbits, constellations, satcom bands, LEO broadband, and the new race to connect ordinary phones directly to spacecraft.
What Is SATCOM? Satellite Communications Explained
SATCOM, or satellite communications, relays signals through orbiting satellites. Here is how uplinks, transponders, orbits, and frequency bands work.
Satellites went from scarce to everywhere
A generation ago, satellites were rare, expensive, and mostly parked in high geostationary orbit. Today thousands of spacecraft fill low Earth orbit, launched by the truckload and replaced on a few-year cycle. That shift, from a handful of exquisite satellites to vast constellations of cheaper ones, is the single biggest change in the space industry, and it is why satellite broadband, real-time Earth imaging, and phone-to-satellite messaging suddenly work.
This section explains the machinery behind that shift without assuming an engineering background. We start with the fundamentals of how a satellite actually works, from its bus and payload to power and station-keeping, then build up to the systems reshaping connectivity.
Orbits and communications
Where a satellite sits determines what it is good for. Satellite communications, or satcom, has traditionally run through geostationary satellites that appear fixed in the sky, using frequency bands from L through Ka. The tradeoff is distance: a signal to geostationary orbit and back travels roughly 72,000 kilometers, adding noticeable delay. Low Earth orbit satellites sit far closer, cutting that delay dramatically, which is why the new broadband constellations live there, at the cost of needing thousands of satellites and constant handoffs as they race across the sky.
The constellations changing connectivity
The best-known LEO constellation is Starlink, SpaceX's broadband network, now joined by competitors like OneWeb and Amazon's Project Kuiper. The next frontier is skipping the dish entirely: direct-to-cell services aim to connect an ordinary, unmodified smartphone to a satellite for texting and, eventually, data, filling the coverage gaps that terrestrial towers never will.
Because Starlink is a division of SpaceX, readers often ask how to invest in it, which we cover in is Starlink publicly traded. And if you just want to see orbital motion for yourself, our live satellite tracker shows where the International Space Station is right now.
How to use this section
Each page is a durable explainer, written to stay accurate as constellations grow. We describe capabilities in ranges rather than exact figures that change weekly, and we hedge anything volatile. Start with satcom or how satellites work if you want the fundamentals, or jump straight to LEO, Starlink, or direct-to-cell.