18 May 2018
Europe’s EDRS system for rapid download by laser link of data from Earth observation satellites has successfully made 10,000 laser connections in the 18 months since operations began, with reliability now running at 99.8%. And, according to Airbus – which operates the system as a public-private partnership with the European Space Agency – the number of connections per month has this year reached 1,000.
EDRS – the European Data Relay System, also called the SpaceDataHighway – currently has a capacity of 40 terrabytes per day and serves Europe’s four Sentinel-1 and -2 satellites; next year the system will also relay information from the Columbus module of the International Space Station and the Pleiades Neo satellites will join from 2020.
The system works by connecting, via a high-capacity laser link, low-Earth orbit satellites to a relay satellite in geostationary orbit, which in turn sends data to the ground. Normally, satellites like the Sentinels have a download window of maybe 10 minutes per 100-minute orbit, when they are in view of a ground station. But for much of their orbit those satellites in LEO can “see” a relay satellite in a 36,000km-high geostationary orbit, and that relay satellite is in constant view of its ground station. The result is a quadrupling of the time per orbit that an observation satellite can transmit data; EDRS has been likened to the internet speed jump achieved by going from copper cables to fibre optics. Aircraft or drones could, if equipped with a suitable laser terminal, exploit this data transmission facility.
EDRS-A, the first relay satellite launched in 2016, offers coverage from the American East coast to India. A second satellite, EDRS-C, will be launched in 2019. It will double the system’s capacity over Europe to 80 terrabytes per day, and extend the coverage and redundancy of the system. Airbus intends to expand the SpaceDataHighway with a third node, ERDS-D, to be positioned over the Asia-Pacific region – providing global coverage.
EDRS is expected to be a feature of all future missions in Europe’s Copernicus EO programme and is available to private customers.