ISRO : Navigation satellite clocks ticking, system to be expanded

Chennai: "The clocks are ticking." Every morning this announcement brings relief and not tension to the Indian space agency team that is managing the navigation satellite system NavIC with only one rubidium atomic clock switched on instead of two in the six satellites.

The phrase signals that the atomic clocks that provide locational data in the six navigation satellites are functioning normally.

Simply put, the Indian Regional Navigation Satellite System (IRNSS) is similar to the GPS (Global Positioning System) of the US, Glonass of Russia, Galileo of Europe and China's Beidou.

Each satellite has three clocks and a total of 27 clocks for the navigation satellite system (including the standby satellites) were supplied by the same vendor.

"The clocks are working well. The signals are good. The replacement satellite for IRNSS-1A will be sent up this year. Already our system is giving precise data even in areas populated with dense buildings and forest areas," said Tapan Misra, Director, Satellite Applications Centre, ISRO.

Misra said it is not only the atomic clocks in the Indian satellite navigation systems that have failed, the clocks in the European system Galileo too have failed as per reports.

The Indian space agency has signed up with several universities in the country to measure the performance of NavIC system, said Misra.

The Rs 1,420 crore Indian satellite navigation system NavIC consists of nine satellites  seven in orbit and two as substitutes.

It is learnt that ISRO has got the atomic clocks replaced in the two standby NavIC satellites. Starting July, 2013, the Indian space agency has launched seven navigation satellites. The last one was launched on April 28, 2016. Each satellite has a life span of 10 years.

The NavIC system was performing well till the three clocks in IRNSS-1A the first satellite failed some months back.