The European Data Relay System (EDRS), also called the SpaceDataHighway, will use two geostationary "relay" satellites to provide real time, high bandwidth links to the lower-flying earth observation satellites. This means the observation satellites are no longer tied to the short contact times during their flight over the respective earth stations and significantly greater quantities of data can be transferred from space to Earth.
The project also plans to use optical laser technology for data transfer for the first time with small laser communication terminals able to transfer up to 1.8Gbit/s over a distance of 45,000km. This has been developed with funding from the German Space Agency (DLR).
The project, run by European satellite maker Astrium for the European Space Agency (ESA), will see four state-of-the-art satellite control stations and data reception facilities at Weilheim, Germany, Redu in Belgium and Harwell in the UK, all operating in the Ka band and supplied by the SES Techcom subsidiary of satellite operator SES in an €11.5m contract announced yesterday.
The first EDRS payload of a laser communications terminal and a Ka-band inter-satellite link, will be carried on board Eutelsat’s new Eurobird 9B satellite. This is due to be launched in 2014 and positioned at the 9°E orbital location.
A second dedicated spacecraft, also carrying a laser communications terminal, will follow in 2015 and will be positioned at 22.5°E. These two elements form the initial core space infrastructure providing direct coverage for the low Earth orbit satellites flying over Europe, the Middle East, Africa, the Americas, Asia and the poles.
Two further spacecraft are planned to complement the system in 2017 and 2019 to give complete coverage of the Earth and providing long-term system redundancy beyond 2030.