The atomic clock: absolute precision for measuring time

The dimension of time, its perception and measurement has been the subject of study and research since antiquity, starting from detailed philosophical analysis by Zeno, Plato and Aristotle. In the sixteenth century, the Renaissance genius Leonardo Da Vinci planned the construction of a leaf-spring clock. A century later, Galileo Galilei sensed the essential characteristic of pendular movement by observing and measuring with his pulse the swinging motions of the chandelier in Pisa’s cathedral. For the construction of the first pendulum clock we will have to wait until the mid-seventeenth century, for the work of Christian Huygens. On the other hand, it was well into the nineteenth century when Leon Foucault, during a famous experiment performed in Paris (1819-1868), was able to demonstrate the Earth’s rotation relative to fixed stars


Since then, science and technology have made extraordinary progress. Today, Leonardo- Finmeccanica boasts among its innovative technological solutions, the most accurate atomic clock ever made, for space travel applications: the Passive Hydrogen Maser (PHM)



The Maser clock, made in Leonardo-Finmeccanica's Nerviano (Milan) site, is used where high levels of precision are required, such as localising, timing, and other applications. Installed on the Galileo Constellation’s satellite navigation system, the Maser clock offers a precision that no space clock has ever had before. Its excellent frequency stability guarantees the accuracy required by the Galileo system for more than eight hours, without any synchronisation by ground control. It accumulates an error of just one second every three million years.  


Leonardo is also involved now in the miniaturisation and reduction in consumption of this product through the realisation of the Mini Maser, with the aim of it embarking on board the Galileo Second Generation (G2G), the second generation of Galileo Constellation satellites.



Maser’s innovative technology can find many fields of application. In fact, the more precise the time measurement is, the greater the tangible benefits derived from it in the ensuing and intersecting daily flow of activities on our planet. An example is the importance of time references in satellite navigation systems, which govern the mobility of people, goods and vehicles or in those for environmental monitoring, watching over land security. 


Born within the framework of the Innovation Award, an initiative that Leonardo-Finmeccanica has promoted internally for over 10 years and that is a true breeding ground for ideas, the Maser is one of the best examples of how a project can be developed and successfully marketed internationally.