The experimental satellite, called Galileo In-Orbit Validation Element, will be used to test equipment on board and the functioning of ground stations.

The following are some key facts about Galileo:

* The Galileo system will consist of a constellation of 30 satellites to provide precise information about the location of an individual or an object. Some of the uses of Galileo include driver assistance, help in search and rescue missions, the monitoring of crop yields and tracking livestock.

* The first operational satellites are scheduled to be launched in 2006, with the system expected to become operational in 2008.

* The non-EU nations which have joined the Galileo project are China, India, Israel and Ukraine.

* Galileo is estimated to cost $4.27 billion to develop and deploy. Some $260 million will be spent each year from 2008 to maintain the system.

* The global market for satellite navigation services is estimated to be 1.8 billion users in 2010, doubling to 3.6 billion in 2020, according to the European Space Agency (ESA).

* Galileo will be interoperable with GPS as well as Russia's global satellite navigation system GLONASS.

* Europe's biggest aerospace companies are part of the Galileo consortium, including EADS, France's Thales and Alcatel, Britain's Inmarsat, Germany's T-Systems, Italy's Finmeccanica and Spain's AENA and Hispasat.

* The Galileo consortium's headquarters will be based in Toulouse, France. Two control centres will be located in Germany and Italy, with additional facilities in Spain.