How Satellite Orbits Work: A Beginner's Guide

Not all satellites are created equal — and neither are their orbits. A weather satellite hovering motionless over the equator, a GPS satellite circling at medium altitude, and the ISS racing overhead every 90 minutes are all following very different paths around Earth. Understanding how satellite orbits work will transform the way you read a live satellite map like SatFleet Live.

In this guide we explain the three main orbit families — LEO, MEO, and GEO — what makes each one unique, and why orbit type is one of the most important factors in satellite tracking.

Why Orbits Matter for Satellite Tracking

An orbit is the curved path a satellite follows around Earth, determined by the balance between its forward velocity and Earth's gravitational pull. Change the altitude, and everything changes: the orbital speed, the period (time per orbit), the coverage area, and how easy the satellite is to track or spot visually.

When you open SatFleet Live and see thousands of dots moving at different speeds across the map, you are watching this physics play out in real time. The fast-moving swarms near the poles are LEO satellites. The barely-moving dots near the equator are GEO satellites. Everything in between is MEO.

Low Earth Orbit (LEO)

LEO is by far the most crowded region of space. At these altitudes, LEO satellites complete a full orbit in roughly 90 minutes, moving so fast they cross your sky in 5 to 10 minutes. The low altitude means excellent ground resolution for Earth imaging, low communication latency for broadband internet, and relatively easy launch costs — which is why Starlink, OneWeb, and other mega-constellations have chosen LEO.

The downside is atmospheric drag. Even at 400 km altitude, trace amounts of atmosphere cause satellites to slow down and gradually spiral inward. Without periodic reboosts, LEO satellites would eventually reenter and burn up. This is why the ISS performs regular engine burns to maintain its orbit, and why TLE data for LEO satellites needs updating every 24–48 hours.

Medium Earth Orbit (MEO)

MEO is less crowded but strategically vital. Navigation systems like GPS use MEO satellites at around 20,200 km because this altitude provides the right balance: each satellite covers a large swath of Earth's surface, and a constellation of 24–30 satellites is enough to guarantee that at least four are visible from any point on the ground at any time — which is the minimum needed for accurate positioning.

MEO satellites move noticeably slower than LEO satellites. On SatFleet Live, you can identify them by filtering for GPS — those dots drift steadily rather than racing across the map. Their TLE data is also more stable, since atmospheric drag is negligible at 20,000 km, and updates every few days are sufficient for accurate tracking.

Geostationary Orbit (GEO)

Geostationary orbit is one of the most elegant concepts in space science. At exactly 35,786 km above the equator, the orbital period equals exactly 24 hours — so a satellite there moves at the same rate Earth rotates, appearing completely stationary from the ground. Point a fixed dish antenna at a GEO satellite once and it will always be in the same spot in the sky.

This makes GEO ideal for television broadcasting, weather monitoring, and communications. A single GEO satellite can see about 42% of Earth's surface continuously. Three well-placed GEO satellites can cover almost the entire planet (except the poles).

The trade-off is latency. At 35,786 km, a radio signal takes about 240 milliseconds each way — nearly half a second round-trip. This makes GEO unsuitable for real-time applications like online gaming or voice calls, which is why Starlink chose LEO instead for its broadband service.

Orbit Comparison at a Glance

How Orbit Type Affects Satellite Tracking

Understanding orbit types changes how you interpret everything on a real-time satellite tracker. Here is what orbit altitude means in practice for tracking:

Speed and pass duration

LEO satellites cross your sky in 5–10 minutes. MEO satellites take hours to move noticeably. GEO satellites are essentially fixed points. If you are using the Next Passes feature on SatFleet Live to plan an ISS observation, expect a brief but bright pass. If you are pointing a dish at a GEO communications satellite, set it once and forget it.

Visibility from the ground

LEO satellites are the easiest to spot with the naked eye precisely because they are close and moving. The ISS, at about 400 km altitude, can reach magnitude −4 — brighter than Venus. GEO satellites at 35,786 km are far too dim and too stationary to notice without a telescope.

TLE accuracy over time

The lower the orbit, the faster the TLE data becomes stale. A LEO satellite's position prediction degrades by kilometres per day due to atmospheric drag. A GEO satellite's TLE can remain accurate for weeks. This is why SatFleet Live prioritises frequent TLE updates and why the satellite count on the map may vary slightly between sessions.

Polar coverage

GEO satellites sit above the equator and cannot see the poles — coverage degrades significantly above 75° latitude. LEO satellites in polar or sun-synchronous orbits (like many Earth observation and weather satellites) cover the entire globe including the poles on each orbit, though only briefly over any given location.

Real Examples: ISS, Starlink, GPS and More

Frequently Asked Questions