European Data Relay System reached first truly milestone on way of its development – first pictures were transmitted from Copernicus satellite.
On 1 June 2016 ESA informed about transmission via European Data Relay System (EDRS). It was performed using Eutelsat-9B satellite to transmit to ground control station images taken by Sentinel-1A satellite operating under ESA Copernicus program.
Sentinel-1A was launched on 2014 on atop of Soyuz-2.1a from Guiana Space Center. As part of the Sentinel-1 series of satellites, its main objective is providing imaging services with C band synthetic aperture radar (SAR). Satellite was based on Prima bus and manufactured under contract signed in by Thales Alenia Space and ESA. Sentinel-1A was also used to perform one of previous tests of EDRS in November 2014 using laser communication equipment installed on Inmarsat-4A F4 satellite.
Result of recently performed test was unveiled on June 1, 2016. It covered transmission of two pictures taken by Sentinel-1A over La Reunion Island; images were taken in high resolution mode and with wide swath mode for both detailed and wide angle pictures. Imaging data were transmitted from Sentinel-1A during flight performed with speed at 28000 km/h to EDRS-A node which remained on GEO orbit. Laser beam used for data transmission achieved high efficiency-speed of transmission was at 600 Mbit/s (laser is able to work with even better data transmission speed, up to 1.8 Gbit/s to provide transmission of 50 TB of data for 24 hours). Distance between Sentinel-1A and EDRS terminal on Eutelsat-9B was 35000 km; process was performed automatically. It is worth to remind that Sentinel-1A remains on orbit with altitude of 693 km and inclination at 98.18° and Eutelsat-9B, launched on 29 January 2016,was placed on GEO orbit (9°E Eutelsat slot) with altitude at 35800 km with inclination at 0.1°. Data from Eutelsat-9B were received by German Space Operations Center in Oberpfaffenhofen and next they were sent to ESA for further analysis and post processing which is necessary to transform RAW data into pictures.
European Data Relay System is developed by ESA independent relay data system operating in real time for satellites, spacecraft, UAVs which are not able to connect with ground control stations directly due the long distance. System is not requiring any regulations of frequency; there is no problem with jamming and system is resistant for Sun influence. EDRS is part of the ARTS (Advanced Research in Telecommunications Systems) program which is joint public-private partnership of ESA, DLR and Airbus Defense and Space. EDRS will provide highly efficient, secure and fast communication with laser beam between satellites or any other vehicles and Ka band transmitters which will communicate with ground stations after receiving data transmitted with laser. First transmission using EDRS was performed between German Terrasar-X satellite and American NFIRE satellite on 21 February 2008. Both spacecrafts were equipped with laser terminals made by German company TESAT, which is prime contractor for EDRS. During first test achieved speed of transmission for 5000 km distance was 5.6 Gbit/s. Second test performed between LEO and GEO satellites was performed on November 2014. Sentinel-1A (Copernicus satellite) transmitted image for 36000 km with TESAT laser terminals to Alphasat satellite; both spacecrafts were equipped with Laser Communication Terminal (LCT) of second generation. Next Alphasat retransmitted image to ground station with on Ka band with radio transmitter.
TESAT laser emitting and receiving terminals were funded by ESA and DLR. Program was developed under public-private partnership with participation of ESA and Airbus Defense and Space. Necessary ground stations were funded by ESA; launch service provider and system integrator will be Airbus Defense and Space, which will become owner of EDRS in future (it is planned for 2030); ESA will still remain main customer, but system will be also offered commercially. Next planned launch of EDRS-B node is planned for 2017. It will be EDRS-C on SmallGEO platform by OHB Systems AG along with HYLAS-3 telecommunication payload.
On picture above: laser communication device attached to International Space Station.