SELEX Galileo will provide its passive hydrogen MASER (PHM) atomic clocks for the Galileo FOC navigation satellites to Surrey Satellite Technology (SSTL) under a €30m ($39.7m) contract.

The PHM clocks will be installed on each of the 14 satellites in the Galileo system.

The clock is the most stable ever produced for space applications with a frequency stability better than 10-14 day.

Eight PHMs are already being integrated into the payloads of the first four satellites of the Galileo IOV navigation system, each satellite being equipped with two PHMs as a master clock.

The frequency stability of the PHMs will provide the precision required by the Galileo system for over eight hours without any correction or upload from the ground.