News Four years of Galileo signals   GIOVE-A ground track showing satellite location at 13:54 UTC on 12 January 2010   13 January 2010   Yesterday, ESA’s Galileo team celebrated the fourth anniversary of the transmission of the first Galileo signal from space.   Over the last four years, the GIOVE-A satellite has been securing the frequencies for the Galileo signals and validating the necessary technologies, such as the atomic clocks. In 2008, GIOVE-A was joined by GIOVE-B, which is also performing these tasks.   Built and operated by Surrey Satellite Technology Ltd, GIOVE-A was launched from Baikonur Cosmodrome on 28 December 2005 with a planned lifetime of two years. The satellite is equipped with a triple-redundant payload and transmits Galileo signals in two separate frequency bands. Given the good performance still available at the end of its expected life, the mission was extended.   More than four years after launch, GIOVE-A is still operating and faithfully transmitting Galileo navigation signals.     Related news  •  GIOVE-A satellite orbit raised (http://www.esa.int/esaNA/SEMFPPQXQZF_galileo_0.html) Related links  •  European Commission - Galileo (http://ec.europa.eu/enterprise/policies/satnav/galileo/index_en.htm)  •  Surrey Satellite Technolgy Limited (http://www.sstl.co.uk/)