International News

PARIS, July 4, (APP/AFP) – Investigators have
uncovered the problems behind the failure of atomic clocks onboard satellites belonging to the beleaguered Galileo satnav system, the European Commission said Monday.
For months, the European Space Agency — which runs the programme —
has been investigating the reasons behind failing clocks onboard some of the 18 navigation satellites it has launched for Galileo, Europe’s alternative to America’s GPS system.
Each Galileo satellite has four ultra-accurate atomic timekeepers,
two that use rubidium and two hydrogen maser. But a satellite needs just one working clock for the satnav to work — the rest are spares.
Three rubidium and six hydrogen maser clocks were not working, with
one satellite sporting two failed timekeepers.
“The main causes of the malfunctions have been identified and
measures have been put in place to reduce the possibility of further malfunctions of the satellites already in space,” commission spokeswoman Lucia Caudet said.
ESA found after an investigation that its rubidium clocks had a
faulty component that could cause a short circuit, according to European sources.
The investigation also found that operations involving hydrogen maser
clocks need to be controlled and closely monitored, the same sources said.
The agency has taken measures to correct both sets of problems, the
sources added, with the agency set to replace the faulty component in rubidium clocks on satellites not yet in orbit and improve hydrogen maser clocks as well.
“The supply of the first Galileo services has not and will not be
affected by the malfunctioning of the atomic clocks or by other corrective measures,” Caudet said, and that the malfunctions have not affected service performance.