ProgrammeThe first experimental GALILEO satellite, GIOVE-A, was launched in December 2005. The objective was to characterise critical technologies that had already been developed. Further experimental satellites include GIOVE-B, scheduled for launch in March 2008 and GIOVE-A2, to be ready for launch in the second half of 2008.  The Galileo Constellation © ESA Thereafter, four operational satellites - the minimum for satellite navigation in principle - will be launched to validate both GALILEO segments - space and related ground infrastructure. Once this In-Orbit Validation (IOV) phase has been completed, the remaining satellites will be placed in orbit to reach the Full Operational Capability (FOC). When fully operational, GALILEO will feature satellites spread evenly around three orbital planes inclined at an angle of 56 degrees to the equator. Each satellite will take about 14 hours to orbit the Earth. One satellite in each plane will be a spare; on stand-by should any operational satellite fail. From most locations, six to eight satellites will always be visible, allowing positions and timing to be determined very accurately to within a few centimetres. Interoperability with the US system of 24 GPS satellites will only increase the reliability of GALILEO services. |