Laser communication terminals for the European Data Relay System

For the first time, laser communication terminals will be operational in a commercial service, EDRS, the European Data Relay System. Future earth observation satellites call for satellite-to-ground links with high availability to make their data immediately available to the user. High availability is only achieved by GEO relay links, i.e. communication links from LEO satellites to a geostationary relay satellite which transmits the data to the ground. While RF communication limits the GEO relay's data rate to roughly 1 Gbps optical communication will extend its capacity into the 10 Gbps range. Today, laser communication terminals operated in LEO-LEO, LEO-to ground and ground-to-LEO links, all at a data rate of 5.625 Gbps, are applied in campaigns with scientific objectives and for technology demonstrating purposes. Adapted to the larger link distance of the LEO-to-GEO link the laser communication terminals will be applied in the GEO relay EDRS operated for the time being at 1.8 Gbps. Terminals will be delivered for the accommodation on Alphabus, EDRS-A and EDRS-C, European GEO-satellites, and on Sentinel-1a and Sentinel-2a, European LEO satellites.