The final countdown for Tara, Samuel, Anna and Ellen begins: Only 1 hour and 30 minutes until the new Galileo satellites are launched into orbit onboard an Ariane 5 launcher.

In short: the European Galileo program is the counterpart to the US GPS system and is though an independent, global satellite navigation system. Tesat-Spacecom's part for the four new satellites was to deliver the essential TT&C transponders, which are being used to properly determine the position of an object in space and though are crucial for a satellite-based positioning serivce.

The launch can be found at this link, the launch is today at 13:00 CEST.

Picture © ESA