Galileo running out of time?

Malcolm Latarche
Malcolm Latarche

24 January 2017


Galileo, the European Union’s GPS system that has yet to begin functioning has suffered a further setback that looks to extend the already 17-year delay and $24Bn budget overrun. The European Space Agency (ESA) has admitted that at least nine atomic clocks across the project’s 18 satellites have failed and are unlikely to be able to be fixed. There were initially ten failed clocks but one has apparently restarted. The clocks are essential to the operation of these satellites, as timing how long it takes for a signal to arrive on Earth is essential to locating where an object is. For the time being, the failures have not affected the functioning of the i- orbit satellites because there are extra clocks on board for redundancy but further failures could make the satellites useless. To function effectively, the system requires 30 satellites but budget cuts and delays have already seen the number of definitely planned satellites reduced to 26. In addition, although initially planned to be more accurate than the US GPS system, the changes made to Galileo means that it will actually be less accurate and will need to rely on the US satellites to boost accuracy. European Space Agency Director-General Jan Woerner said on 18 January that the agency has not decided whether to go ahead as planned with an Ariane 5 launch in August of the next batch of four Galileo spacecraft. The launch is one of two scheduled over the next two years to complete the constellation needed to give Europe’s GPS alternative global coverage. In a statement ESA said that it was committed to launching the next four satellites before the end of the year and that while investigations continue has agreed with its industrial partners “that some refurbishment is required on the remaining clocks still to be launched on the eight Galileo satellites currently being constructed or tested.