Technology
Low Earth Orbit Satellite Constellation Internet
Quick fact
A LEO satellite orbits at just 500 km altitude, requiring about 90 minutes to circle Earth—and because it's so close, internet latency can be as low as 20–40 ms, comparable to cable broadband.
Why this is interesting
You’ve probably heard of Starlink, but have you wondered how a network of thousands of satellites can beam high-speed internet to your dish while zooming around Earth at 27,000 km/h?
Read the full explanation
Understanding Low Earth Orbit Satellite Constellation Internet
Imagine trying to shout across a football field versus whispering in someone's ear—being closer means faster communication. Traditional internet satellites park much farther away (about 35,000 km), so signals take a noticeable round trip. LEO satellites fly close to Earth, only a few hundred kilometres up, cutting that delay dramatically. Because they move fast and are not stationary, you can't rely on just one; instead, you need a whole 'constellation'—a coordinated fleet of satellites that work together. When one satellite disappears over the horizon, your connection seamlessly hands off to the next one, like a relay race with a baton of data. Your ground dish tracks the satellites automatically, keeping you online as the network orbits the globe.
A deeper explanation
The key to LEO internet is the low altitude, which drastically reduces the distance a signal must travel. The speed of light is finite (about 300,000 km/s), so geostationary satellites, which sit ~35,786 km up, add roughly 120 ms of round-trip delay just from the perpendicular travel—plus extra for path bends. LEO satellites at ~550 km cut that to mere milliseconds. But because they orbit every ~90 minutes, no single satellite is always overhead. So constellations use a large number of satellites (sometimes thousands) in multiple orbital planes, covering the whole globe. They communicate with ground stations and sometimes with each other via laser or radio links, routing data like a mesh network in the sky. This design enables high-speed, low-latency broadband to every corner of the planet, from oceans to deserts, and is reshaping how the world connects.