Galileo is the global navigation satellite system (GNSS) that is currently being created by the European Union (EU) and the European Space Agency (ESA).[1] The €5 billion project[2] is named after the Italian astronomer Galileo Galilei. One of the aims of Galileo is to provide an indigenous alternative high-precision positioning system upon which European nations can rely, independently from the Russian GLONASS and US GPS systems, in case they were disabled by their operators.[3] The use of basic (low-precision) Galileo services will be free and open to everyone. The high-precision capabilities will be available for paying commercial users. Galileo is intended to provide horizontal and vertical position measurements within 1-metre precision, and better positioning services at high latitudes than other positioning systems.
In December 2010 EU ministers in Brussels voted Prague in the Czech Republic as the headquarters of the Galileo project. Since 2012, the headquarters are located in Prague's district of Holešovice. In operation Galileo will use two ground operations centres, Oberpfaffenhofen near Munich in Germany and Fucino in Italy.
On 21 October 2011 the first two of four (Galileo #1 and #2) operational satellites were launched to validate the system. The next two (Galileo #3 and #4) followed on 12 October 2012, making it "possible to test Galileo end-to-end".[4] Once this In-Orbit Validation (IOV) phase was completed, additional satellites are being launched to reach Initial Operational Capability (IOC) around mid-decade. The first determination of a position relying on signals emitted only from Galileo satellites was achieved on 12 March 2013.[5] On 22 August 2014, two (Galileo #5 and #6) more satellites were launched from French Guiana[6] but were injected into an incorrect orbit.[7] Analysis indicated that the third stage of the Soyuz launch vehicle, the Fregat space tug, failed to circularize the satellites' orbit correctly, resulting in a semi-minor axis 3,700 km (2,300 mi) less than desired and a 5° inclination error.[8][dated info] These orbits have now been corrected (December 2014 and March 2015) at the cost of reduced propellant, shortening the life-span of the satellites to 12 years operation.[9][10] On 27 March 2015 the next two (Galileo #7 and #8) satellites were launched successfully from Guiana Space Centre using a Soyuz four stage launcher.[11][12] Using the same Soyuz launcher and launchpad, satellites number 9 and 10 were launched successfully on 11 September 2015.[13]
Galileo is planned to provide[when?] a unique global search and rescue (SAR) function. Satellites will be equipped with a transponder which will relay distress signals from the user's transmitter[clarification needed] to the Rescue Co-ordination Centre, which will then initiate a rescue operation. At the same time, the system is projected to provide a signal to the users, informing them that their situation has been detected and help is on the way. This latter feature is new and is considered a major upgrade compared to the existing GPS and GLONASS navigation systems, which do not provide feedback to the user.[14] Tests in February 2014 found that for Galileo's search and rescue function, operating as part of the existing International Cospas-Sarsat Programme, 77% of simulated distress locations can be pinpointed within 2 km, and 95% within 5 km.[15]
Galileo will start offering first services from 2016.[16] Full completion of the 30-satellite Galileo system (24 operational and 6 active spares) is expected by 2020.[17]