In the 1990s, there were already initial implementations for satellite Internet using satellites in a wide variety of orbits. In some of these concepts, predominantly GEO and MEO satellites, the latency caused by the transit times from the ground station to the satellite and back again impair Internet services such as Internet telephony
to such an extent that they cannot be used. In order to achieve global coverage of the Internet via satellites and also to be able to use services
thatare sensitive to delay times, LEO satellites
, which orbitthe earth
inlow orbits at altitudes of between 700 km and 1,500 km
, are the obvious choice. LEOsatellites
have asmall footprint due to their low orbit, which is why hundreds or even thousands of LEO satellites are needed to cover a large part of the Earth. The concept with the LEO satellites is pursued in Starlink, a global satellite network initiated by the US space company SpaceX. According to plans, Starlink intends to operate 1,500 satellites in an orbit of 550 km in the first expansion stage. The following expansion stage envisions 2,800 satellites in orbits between 1,100 km and 1,325 km. A further 30,000 satellites are planned for low orbits between 300 km and 600 km. In total, the Starlink satellites are distributed over more than 20 orbital planes. To ensure that regional areas are continuously supplied with the Internet, the satellites pass on their data to other satellites via Inter Satellite Links
(ISL). The ISL connection is made via laser light beams. Starlink is designed as a high-speed Internet and is intended to provide each user with a data transfer rate of 1 GB/s.