Space laser communications satellite launches

The first node of the European Data Relay System is in orbit, promising much faster relay of important scientific data

A space laser system blasts into orbit

Up, up and away. A Russian Proton rocket carrying the Eutelsat 9B satellite lifts off from the Baikonur Cosmodrome. It’s destined to send hundreds of TV channels to European homes.

But it has something much more interesting on board: the first node of a laser communications system called the European Data Relay System or EDRS.

EDRS hopes to solve a problem that currently affects satellites in low earth orbit. This is about 400 to 600 kilometers above earth. That’s much closer than the 36,000 kilometers of TV and telecom satellites like Eutelsat 9B.

The satellites fly low because they’re taking pictures or collecting scientific data. But the low orbit means they are often out of range of a ground station that can receive their signals.

In a typical 90 minute orbit, they might only be able to transmit data for 10 minutes, so delays occur.

Because Eutelsat 9B is much higher, it can keep contact with the low earth orbit satellite for much more of its orbit, and that’s where EDRS comes in. The two satellites link via laser that can carry data at up to 1.8Gbits per second — much faster than a comparable a radio system could manage.

And because Eutelsat 9B is in geostationary orbit, it appears at the same place in the sky so is always in contact with a ground station.

The set up means much less delay in getting data back to scientists and emergency services.

The system will get its first proper test later this year when the Copernicus Sentinel-1 and -2 satellites are launched. EDRS can handle up to 50 terabytes of data per day, speeding the transmission of important satellite data

If it all works, the European Space Agency plans to launch a dedicated EDRS satellite in 2017 and move towards a global system from 2020.