Lift-off for Europe's space laser network

For some applications - such as the monitoring of pollution incidents, or illegal fishing or ocean piracy - the time saved could be critical to achieving an effective response.
The European Data Relay System, or EDRS for short, has been more than 10 years in development. Getting satellites to talk to each other via a narrow laser beam is no easy task, says Esa project manager Michael Witting.


"The difficulty is basically that you have to hit another satellite with your laser beam over a distance of over 40,000km, which is akin to hitting a two-euro coin over the distance of the Atlantic," he told BBC News.
With a successful connection, data will move at a rate of up to 1.8Gbps.

EDRS will debut with the European Commission as its anchor customer. Brussels has a series of satellites called Sentinels that are systematically mapping the Earth, to help inform and enforce EU policies.
Prodigious volumes of data are expected from these satellites in the coming years and the traditional downlink solutions are no longer regarded as adequate to the task.

Esa officials will only declare Friday's launch a success when they get confirmation that the relay satellite survived its ride to orbit.
The spacecraft, which is owned by the Paris-based commercial operator Eutelsat, left the Kazakh Baikonur cosmodrome atop a Proton rocket at 22.20 GMT on Friday (04:20 local time Saturday).
The drop-off high above the Earth was not expected to occur until nine hours and 12 minutes after lift-off, meaning it would be 07:32 GMT on Saturday, at the earliest, before ground controllers could assess the status of the mission.

Many weeks of testing lie ahead. EDRS should go into full service in the summer.
A second relay satellite will go up in 2017. Further platforms will be required to provide fully global, round-the-clock laser connections.