LEO satellites: Crowded heavens 

Far above our heads, the heavens are getting crowded. More and more satellites are orbiting the Earth: four years ago, there were fewer than 3,000 active satellites in orbit—now there are over 7,000. And by the year 2030, that figure could quadruple. The main driver of this strong growth is the increase in the number of LEO satellites.

LEO stands for low Earth orbit—the path taken by fast-orbiting communications satellites. Orbits in the LEO region are between around 250 and 2,000 km above the Earth’s surface. This means that these satellites can have short signal transit times compared to those in higher orbits and can be deployed on shorter—and thus cheaper—rocket flights. But there are downsides: The low orbit means that more communications satellites are needed to provide coverage to the entire surface of the Earth. What’s more, the air resistance still present in that region leads to greater wear and tear. While today’s LEO satellites orbiting at 550 km tend to burn up in the Earth’s atmosphere after about five years, a modern, four-metric-ton GPS satellite in a middle Earth orbit (MEO) at an altitude of over 20,000 km will have a service life of 15 years.

There are more than a dozen global LEO satellite operators offering not only phone services but a wide range of data, multimedia, and video services as well. The most well known and ambitious example of LEO satellites is the Starlink system owned by US entrepreneur Elon Musk’s company SpaceX. Between 2020 and mid-2023, the company installed more than 4,500 satellites 550 km above the Earth. Every week, SpaceX sent up one of its reusable Falcon 9 rockets to put up to 50 of these 300 kg Starlink satellites into orbit at once—an economical way to build up the system. There is now a new generation of Starlink satellites, but as they weigh considerably more (1.25 metric tons each), getting them into space won’t be quite as cost-effective. Nevertheless, Starlink plans to put more than 7,000 of these into orbit. Their launch has already been approved by the relevant US authorities.

Internet from space

Starlink’s specialty is providing people with internet access without the need for mobile communications networks and stationary hookups. Users require transmitter and receiver units, which are about the size of a milk carton, and a satellite dish. Tests carried out by DACHSER Corporate Research & Development recorded data rates of between 50 and 200 Mbit/s. The availability and reliability of a basic internet connection were rated between “good” and “very good.

LEO communications solutions are being developed at an impressive pace: Starlink and its partners have announced that they will be testing satellite internet for aircraft and smartphones in 2023. Apple’s iPhone 14 already comes with an emergency SOS via satellite function, which allows users to exchange short messages with emergency services even when no mobile network is available. This two-way communication is made possible through 48 LEO satellites orbiting the Earth at an altitude of 1,400 km and operated by Globalstar.

Other providers are also attempting to compete with LEO internet market leader Starlink. These include the UK provider OneWeb, Amazon, and government initiatives in China and the European Union. The EU has announced its intention to launch some 170 LEO devices into orbit by 2027 to establish an independent satellite data network.

As this future technology gradually becomes reality, in theory it offers logistics the option of maintaining data communication with loading units, vehicles, and transit terminals even when 4G and 5G networks are unavailable. Which applications will ultimately prove viable will be decided largely by the size, energy requirements, and cost of the transmitter and receiver devices as well as by the actual availability of data transmission bandwidths. DACHSER will continue to explore these options as part of its research and innovation activities.

Author: Andre Kranke, Head of Corporate Research & Development at DACHSER