Europe's satellite laser comms system set to shine

The European Space Agency (ESA) and Airbus Defence and Space are poised to launch the first orbiting component of the European Data Relay System (EDRS), aka the "SpaceDataHighway", described as "the most sophisticated laser communication network ever designed".

On 27 January, the EDRS-A node will lift off from Baikonur Cosmodrome atop a Russian Proton rocket. In 2017, it'll be followed by the EDRS-C satellite, which will be carried aloft by a Ariane 5 from Kourou, French Guiana. Once up and running, the two geostationary (GEO) nodes over Europe will receive data from other Low Earth Orbit (LEO) satellites via laser links and beam it earthwards to ground stations at rates up to 1,800 Mbit/s.

Fast: The EDRS laser communications terminal

ESA explains:

Earth-observing satellites travel in low-Earth orbit (LEO) gathering data and making a full circuit of Earth about every 100 minutes. They must wait to be over their respective ground stations to downlink the information they have acquired, however. Generally, this leaves only 10 minutes out of every 100 to transfer their information to the users on the ground. Any data gathered between these windows must be stored until the next downlink opportunity.

EDRS solves the downlink delay by connecting to the LEO satellites as they orbit past. EDRS collects the LEO data from its higher position in GEO and relays it down to its European ground stations, avoiding the time delay that occurs when the LEO satellite has to wait for 'line of sight' with its ground station. In fact, just one of the EDRS nodes can quadruple the Earth observer’s contact time with its ground segment.

ESA is the "anchor customer" for EDRS, with its Copernicus Sentinel-1 and -2 satellites. Ultimately, the aim is to attract more users with an extended EDRS ("GlobeNet"*), boasting further satellites offering global coverage. ®

Bootnote

*Mercifully not dubbed "Skynet".