Low Earth Orbit: The New Cell Tower?

Satellite internet used to mean a large dish, a modest speed, and a delay long enough to make a video call painful. Traditional geostationary satellites sit about 36,000 kilometers up, so a round trip takes around 600 milliseconds. Low-earth-orbit constellations fly at only a few hundred kilometers, which brings latency down to tens of milliseconds, close to a decent terrestrial connection.

How a constellation works

At that altitude a satellite crosses the sky in minutes, so one spacecraft cannot serve anyone for long. Coverage therefore takes hundreds or thousands of them, each handing users off to the next. Early designs relayed traffic straight down to a ground station. Newer satellites pass data between themselves using laser links, so a signal can cross an ocean without touching the ground. SpaceX's Starlink is by far the largest of these systems, with many thousands of satellites in orbit, while Amazon and others are racing to catch up.

Who actually needs it

The clearest market is anywhere fiber will never reach: remote homes, mines, research stations and aircraft. Maritime customers took to it quickly. Cruise lines were among the most enthusiastic, because a ship full of passengers wants to stream, post and call just as it would at home. The onboard casino has also become less isolated from the shore. Slot systems, player accounts and card payments on a modern ship can now sync far more often than they could over the slow satellite links of a few years ago.

Satellites that talk to phones

The newest development is direct-to-device service, where a satellite acts like a very distant cell tower and connects to an ordinary phone with no extra hardware. Partnerships between satellite firms and mobile operators launched commercially in the past few years, starting with text messages and basic data. It is a lifeline in a dead zone, not a replacement for a local network, since the capacity per satellite beam is small and shared across a very large area.

Where the physics pushes back

• Capacity per area. A single beam covers a wide patch of ground, so dense cities overwhelm it quickly. Satellites suit sparse areas far better.
• Lifespan. Low-orbit satellites last only about five years and must be replaced continually, so launch costs never go away.
• The sky itself. Astronomers have raised concerns about light pollution and radio interference, and orbital debris is a growing worry.

A complement, not a successor

The best way to view these constellations is as another layer of the network. They will not replace fiber or towers where those already exist, but they do fill the gaps. Their arrival has also set a useful floor on what any rural broadband project now has to beat. Even so, the satellites still connect back to earth, usually at sites linked by the kind of fiber we discussed in our essay on glass.