|Mission type||Data transmission|
|Operator||German Aerospace Center|
|Website||European Data Relay System|
The European Data Relay System (EDRS) system is a European constellation of GEO satellites that relay information and data between satellites, spacecraft, UAVs, and ground stations. The first components (a payload and dedicated GEO satellite) were launched in 2016 and 2019.
The designers intend the system to provide almost full-time communication, even with satellites in low Earth orbit that often have reduced visibility from ground stations. It makes on-demand data available to, for example, rescue workers who want near-real-time satellite data of a crisis region.
There are a number of key services that will benefit from this system's infrastructure:
The system has been developed as part of the ARTES 7 programme and is intended to be an independent, European satellite system that reduces time delays in the transmission of large quantities of data. The programme is similar to the American Tracking and Data Relay Satellite System that was set up to support the Space Shuttle—but EDRS is using a new generation Laser Communication Terminal (LCT) which carries data at a much larger bit rate: the laser terminal transmits 1.8 Gbit/s across 45,000 km (the distance of a LEO-GEO link), while the TDRSS provides ground reception rates of 600 Mbit/s in the S-band and 800 Mbit/s in the Ku- and Ka-bands.
Such a terminal was successfully tested in 2007/8 during in-orbit verification between the German radar satellite TerraSAR-X and the American NFIRE satellite, both in LEO, when it achieved 5.5 gigabits per second. A similar LCT was installed on the commercial telecommunication satellite Alphasat.
EDRS infrastructure will consist of two geostationary payloads (two further payloads are in the planning stage), a ground system consisting of a satellite control centre, a mission and operations centre, a feeder link ground station (FLGS), and data ground stations.
The first EDRS payload, EDRS-A, comprising a laser communication terminal and a Ka band inter-satellite link, was placed on-board Eutelsat commercial telecommunication satellite, called Eutelsat 9B (COSPAR 2016-005A). The satellite was launched in January 2016 by a Proton-M rocket and will be positioned at 9°E.
A second EDRS payload was launched aboard a dedicated spacecraft. The EDRS-C (COSPAR 2019-049A), which is also carrying a laser communication terminal, was launched on 6 August 2019 and will be positioned at 31°E. The satellite also carries a payload meant for commercial communication satellite use, the HYLAS 3 payload. Thus the satellite is sometimes referred to as EDRS-C/HYLAS 3 or something similar.
The EDRS A and C form the initial core space infrastructure that provides direct coverage for LEO satellites over Europe, the Middle East, Africa, the Americas, Asia, and the Poles. Two further spacecraft are planned to complement the system from 2020 onwards, affording a complete coverage of the Earth and providing long-term system redundancy beyond 2030.
The ground segment of EDRS includes three ground receiving stations located at Weilheim, Germany, Redu, Belgium and Harwell, UK. The prime Mission Operations Centre is in Ottobrunn, Germany, while a backup centre will be installed in Redu, Belgium.
The EDRS-A payload as well as the EDRS-C satellite are operated by the German Space Operations Center (GSOC) of the German Aerospace Center in Oberpfaffenhofen near Munich, Germany.
The first users for EDRS will be the Sentinel-1 and -2 satellites of the Copernicus Programme (formerly the Global Monitoring for Environment and Security or GMES). The Sentinel satellites will provide data for the operational provision of geo-information products and services throughout Europe and the globe. EDRS will provide the data relay services for the Sentinel satellites facilitating a rapid downlink of large volumes of imagery. Extensive further capacities on the system will be available for third party users.[needs update]
EDRS is being implemented as a Public Private Partnership (PPP) between the European Space Agency (ESA) and Airbus Defence & Space (ADS, former Astrium). ESA funds the infrastructure development and is the anchor customer through the Sentinel satellite missions. ADS will carry the overall responsibility for the implementation of the space segment including launch, as well as the ground segment. ADS will then[when?] take over ownership of EDRS and will provide the data transmission services to ESA and customers worldwide. [needs update]