PARIS — Europe’s satellite data-relay system, which is targeting the U.S. Defense Department as a major prospective customer, is accelerating deployment this year with the launch of satellites carrying laser terminals to low Earth orbit and to geostationary orbit.
For Astrium Services, which is developing the European Data Relay Service (EDRS) in partnership with the 20-nation European Space Agency (), the push to attract U.S. military interest will include laser-communications tests between a satellite and a ground station installed on Mount Wilson in California.
Astrium has already tested satellite-to-ground links at ESA’s Optical Ground System in Spain’s Canary Islands. But nothing beats tests conducted in the backyard of a customer like the U.S. Defense Department, said Ako Hegyi, EDRS program manager at Astrium Services.
“It’s always good to be close to potential stakeholders,” Hegyi said in an April 5 interview explaining why the Mount Wilson campaign was needed on the back of the Canary Islands tests. “And the fact is that the laser terminals were not initially made for leo-to-ground links or geo-to-ground links. We are now looking at adaptive optics to improve” the reliability of transmissions between low-orbiting and geostationary-orbiting satellites, and between these satellites and the ground.
Developed by Tesat of Backnang, Germany, with funding from the German Aerospace Center, DLR, the laser communications terminals have already been well-tested in transmissions between the U.S. Missile Defense Agency’s NFIRE satellite and Germany’s TerraSAR-X radar Earth observation satellite.
Since 2012, the system has been tested using a Falcon business jet.
Optical transmissions are less easy to disrupt or jam than radio frequency signals, and they do not need to be coordinated with international regulators at the International Telecommunication Union.
ESA and the European Commission plan to use EDRS to relay environmental data from low-orbiting observation satellites to geostationary-orbit satellites for faster delivery to ground users.
Europe’s Sentinel 1A and Sentinel 1B environment-monitoring satellites, scheduled for launch by 2014, will both be equipped with laser communications terminals, as will the large Alphasat multimission spacecraft scheduled for launch this summer into geostationary orbit. Mobile satellite services providerof London will use Alphasat’s L-band payload for Inmarsat’s commercial business, but the spacecraft includes several ESA-funded technology demonstration payloads, including a laser terminal.
Transmission speeds of 1.8 gigabits per second are expected for the links between low-orbiting and high-orbiting satellites. The transmission between NFIRE and TerraSAR-X, both in low Earth orbit, was triple that speed.
Two further geostationary satellites with laser terminals are under construction. Atelecommunications satellite planned for launch late this year or early in 2014 will be located at 9 degrees east, and a telecommunications satellite to be used by Avanti Communications of London at 31 degrees east is scheduled for launch in mid-2014.
“With these two satellites we can provide near-global coverage to low-orbiting satellites because the elevation angle we need is very low,” Hegyi said. For airborne applications — aircraft or unmanned aerial vehicles — the coverage stretches from the extreme northeast of North America across Europe, Central Asia, South Asia and to most of East Asia. The service is promising direct data delivery to any NATO or coalition teleport in Europe.
Astrium Services, with its sister company Astrium Satellites, is looking for other opportunities among commercial satellite operators to place a laser terminal on a satellite over North America to afford full global coverage.
Astrium Services is pitching the service to the U.S. military as a possible partnership in which the customer would provide a launch in return for access to data. The company is also pursuing a cooperation arrangement with MDA Corp. of Canada, and the Canadian government, which recently began full construction of the three-satellite Radar Constellation Mission.