Low Earth Orbit

A satellite is a device that orbits the Earth instead of standing on it. To keep it from falling down, it has to fly sideways very fast. Low Earth Orbit refers to the region where it does this at low altitude: roughly between 160 and 2,000 kilometers above the ground. For comparison: it’s about 600 kilometers as the crow flies from Hamburg to Munich. So a satellite up there isn’t actually as far away as you might think. It takes about 90 minutes to complete one loop around the Earth, covering around 28,000 kilometers per hour in the process.

Why short distances in space determine internet speed

Radio signals travel at the speed of light, but even that is finite. The longer the path, the longer the delay. Older communications satellites sit at an altitude of around 36,000 kilometers, in what’s called geostationary orbit. From the ground, they appear to stand still because they orbit at exactly the same speed as the Earth rotates. That’s convenient for TV reception, but the round trip of the signal takes more than half a second.

In Low Earth Orbit, it’s only a few hundredths of a second. This delay is called latency. For video calls, online gaming, or remote-controlled machines, it determines whether something runs smoothly or stutters uselessly. That’s why companies like SpaceX with Starlink or Amazon with Kuiper are building their internet networks at this altitude.

Economically, this region has become interesting because rocket launches have gotten significantly cheaper. Reusable rockets and small, mass-produced satellites have driven down the cost per kilogram of payload considerably. What was once a field for states and a handful of corporations has become a market with many providers.

Chains of thousands of satellites instead of individual giants

The big drawback of low altitude: a single satellite only ever sees a small slice of the Earth. And because it keeps flying onward, it disappears from your location within a few minutes. So a single device can’t provide continuous coverage for a region. The solution is constellations: many satellites on coordinated orbits that hand off from one another.

Starlink now operates several thousand such satellites. Your antenna at home automatically switches to the next one as soon as the current one drops below the horizon. Think of it like a relay race: each runner carries the baton only a short distance, but the chain never breaks. Many satellites also relay data directly to each other via laser, instead of sending it down to the ground every time.

At this altitude, there are also remnants of the atmosphere. This thin air slowly brakes the satellites. Without regular boosts from small thrusters, they sink after a few years and burn up. This is annoying on one hand, but a self-cleaning effect on the other: faulty technology doesn’t stay up there forever.

From cell phone reception in the countryside to disputes over space debris

In everyday life, you encounter Low Earth Orbit mainly through internet connections in areas without fiber optics, such as farms, ships, or crisis regions. Earth observation also happens there: the images in map services, weather forecasts, and footage of wildfires often come from satellites at this altitude. The International Space Station also orbits in Low Earth Orbit, at an altitude of around 400 kilometers.

In the news, the term often comes up in connection with data centers and AI. The idea behind this: whoever runs models in space has unlimited sunlight there and free cooling from the cold of space. Such plans are experiments so far, not finished products. The data connection to the ground remains the bottleneck.

The biggest problem is space debris. Decommissioned satellites and fragments continue flying at several kilometers per second. Even a piece the size of a screw can destroy a functioning satellite. Astronomers also criticize that the bright satellite chains disrupt their images of the night sky. Anyone reading about Starlink or Kuiper will almost always find these conflicts in the fine print.