After GIOVE-B, the validation in orbit will be completed with the launch of four further satellites - the minimum required to obtain a satellite navigation position measurement. These satellites are currently being built at locations across Europe, for launch from the end of 2009.
To reach operational status, Galileo needs a constellation of 30 satellites and an associated network of ground stations spread all around the globe. This phase has just been confirmed with the decisions taken by the European Union, which has agreed on a financing package of € 3.4 billion Euros and proposed to entrust ESA with the full deployment of Galileo by 2013.
While waiting for Galileo, another positioning system is in its pre-operational phase in Europe. EGNOS, the European Geostationary Navigation Overlay System, is a network of ground stations that improves GPS signals and retransmits them via geostationary satellites. EGNOS allows position determination accurate to within two metres. Originally designed to improve air traffic safety, EGNOS is accessible to all and paves the way for Galileo.
With these steps, the European Commission and ESA are progressively setting up a civilian system able to offer guidance and help worldwide.
