The European Space Agency (ESA) announces that nine atomic clocks on satellites of the Galileo navigation system no longer work. There are four clocks per satellite, three of which serve as backups. The problems do not affect the operation yet.
According to the AFP news agency, ESA reports that six hydrogen maser clocks are defective and that three rubidium clocks no longer work. It is not yet clear whether the clocks can be reactivated, says ESA CEO Jan Woerner.
Each Galileo satellite has four atomic clocks, two of each type. Two clocks on one satellite are broken. Since only one working clock per satellite is required for system operation, the defects do not affect the operation of Galileo.
The European Space Agency does not know what caused the atomic clocks to go out and is currently investigating whether this is a systematic problem. If so, it may be decided to postpone the launch of new Galileo satellites. If no systematic cause is found, the ESA will continue to launch the satellites and ESA will have to rely on the presence of the backup clocks.
There are currently eighteen satellites for the navigation system in orbit. The European GPS alternative has been partially operational since December. Two more launches are planned, for 2017 and 2018. The entire system should be operational by 2020. It will then consist of thirty satellites, six of which are reserves.