Ensuring that planes land safely, that ships find their routes, that banks carry out their transactions, and that we find our way through unfamiliar cities, all require help from above. Satellite networks are an indispensable part of the infrastructure of modern societies. Not only do they support us in our everyday lives, they also enable activities such as climate research and weather forecasts, and provide data on changes in the oceans or the melting of glaciers.
Germany has had satellites in space since 1969, currently more than 80. At an altitude of roughly 500 kilometers, TerraSAR-X and TanDEM-X orbit the Earth and scan its surface with high precision using radar equipment. These satellites have already mapped the entire surface of the Earth several times and, among other things, demonstrated the extent of climate change: For example, the highly accurate radar data demonstrated losses in the ice thickness of the Great Aletsch Glacier in Switzerland of up to 50 meters over just a few years.
