During a press conference on Wednesday 18 January, the Director-General of the European Space Agency (ESA), Jan Wörner, announced that the multiple breakdowns in the atomic satellite clocks in the European Galileo navigation constellation programme, could possibly lead to delays in the launch of the next batch of satellites.
The atomic clocks play a crucial role in the accuracy of navigation satellites, explained the Director-General, as part of his introduction. He also said that in an effort to improve the precision and reliability of the Galileo system, no fewer than four atomic clocks had been installed on each satellite. Mr Wörner indicated that so far, for reasons that are still not yet known, nine clocks had failed (three rubidium and six hydrogen maser clocks are not working). According to another source five satellites have been affected out of the 18-satellite constellation.
The question of why these failures occurred is crucial if they are to work out whether they are systematic or not and whether they will have to delay putting into orbit the next satellites to complete the Galileo constellation, explains the Director-General. He added that the question is more complicated than it would appear because not launching the new satellites could ultimately mean reducing the long-term capacity of the constellation and that launching new satellites could help to “maintain or indeed increase” constellation capacity. Satellites are effectively deemed operational as long as the on-board timekeepers are functioning.
This is yet another concern since the initial services were launched as recently as last December (see EUROPE 11689) and the fact that the Galileo space programme is a priority within the European Space strategy with implications on the security and defence goals of member states (see EUROPE 11655). (Original version in French by Pascal Hansens)