The Indian space agency ISRO (Indian Space Research Organisation) has recently developed an atomic clock with the aim of using it in navigation satellites for measuring the precise location data. The agency has been using atomic clocks imported from Astrium, European aerospace manufactures for its navigation satellites.
An ISRO official stated that the SAC (Space Applications Centre) has successfully developed a native atomic clock and will be ready to use after it undergoes some qualification tests. And once the desi atomic clock clears all the tests, it will be fitted in an experimental navigation satellite to further test its durability and accuracy in space.
With the development of its own atomic clock, ISRO has managed to become one of the very few space organizations that have achieved the capability to develop this very high sophisticated technology in the entire world. The desi clock is said to be as good as the imported one and is expected to work for more than 5 years without any trouble.
Seven satellites have been launched so far as a part of the NaVIC or IRNSS (Indian Regional Navigation Satellite System), and each satellite had 3 Rubidium atomic clocks which are imported. All the atomic clocks in these seven satellites launched are synchronized. The difference in time between all the atomic clocks of these different satellites positioned at entirely different orbits are used to find the accurate position of a navigation receiver or an Earth object. Even if a single clock malfunction, the measurements and time differences calculated between it and the other clocks of other satellites will also be inaccurate, which in turn will give wrong positioning of an object. Other than atomic clocks, navigations are also fitted with crystal clocks which give a little less accurate information compared to atomic clocks. So, if 3 atomic clocks of any satellite show an error, a new backup satellite will have to be launched with a new set of atomic clocks.
According to the information received, nine atomic clocks of the launched 21, in some of the navigation satellites are showing error data. Therefore, ISRO is planning to launch four navigation satellites as a backup to keep the navigation in India effective. The backup satellites which will be sent will have the indigenous atomic clocks inside and are waiting for the financial clearance from the government.