A. What is the difference between low-earth orbit (LEO) and traditional Geostationary-Earth Orbit (GEO) satellite Internet services?

Satellite technologies play an important role in global connectivity and earth observation. Both Low Earth Orbit (LEO) and Geostationary-Earth Orbit (GEO) satellites are used to provide internet connectivity services, but they differ significantly in their characteristics and performance.

LEO Satellites (e.g., Space X Starlink satellites) orbits the earth at low altitudes of between 200 and 2000 Kilometres. Because of this, LEO systems require a large constellation (sometimes 1000s) of satellites to provide global coverage. GEO satellites on the other hand orbit the earth at 35,786 KM and require about 3 satellites for global coverage (see Figure 1). They are called GEO satellites because they rotate at the same speed as the earth and so appear stationary.

The proximity to the earth of LEO satellites offers lower latency and higher speeds compared GEO satellites translating to superior user experience. LEO satellites communicate with each other in a constellation using lasers but are also connected to terrestrial communications at selected earth station hubs. Examples of LEO satellites operators with coverage in Kenya and Africa are Starlink and EUTELSAT Oneweb. The cost of setting up and maintaining a LEO satellite system is very high due to the high number of satellites required to operate. Moreover, LEO satellites operate in much harsher environments as compared to GEO satellites that include atmospheric drag resulting in a shorter lifespan of only about five years. A large number of replacement satellites must be launched every year.