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Navigation satellite clocks ticking; system to be expanded: ISRO

Starting July 2013, the Indian space agency has launched 7 navigation satellites

IANS  |  Chennai 

Navigation satellite clocks ticking; system to be expanded: ISRO

"The clocks are ticking." Every morning this announcement brings relief and not tension to the Indian space agency team that is managing the navigation system 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.

Three atomic clocks in the first navigation have already failed.

"The clocks are ticking well. It's not possible to share the technical details of mission management for important reasons. is adopting various strategies so that best results are obtained from its systems," A S Kiran Kumar, chairman, Indian Space Research Organisation (ISRO) told IANS on Saturday over the phone.

Sources close to ISRO, on the condition of anonymity, told IANS that two more atomic clocks in the system started showing abnormalities thereby taking the total number of failed clocks to five.

"Hence as a precaution and also to extend the operational life of satellites, the is running the system with one clock switched on instead of two. If the running clock fails then the standby clocks will be switched on," sources said.

The initial plan was to keep two clocks in the on while keeping the third one on standby.

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

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

The clocks are important to provide precise locational data.

"The clocks are working well. The signals are good. The replacement for 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, Space Applications Centre,

According to him, space sector is an unforgiving business and hence mission management is important.

Misra said it is not only the atomic clocks in the Indian 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 system, said Misra.

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

"We are already using the system for several applications. The replacement for will be launched in July or August. There are also plans to expand the system by taking the number of satellites to 11 from seven," Kumar said.

It is learnt that has got the atomic clocks replaced in the two standby satellites.

Starting July 2013, the Indian space agency has launched seven navigation satellites. The last one was launched on April 28, 2016. Each has a lifespan of 10 years.

The system was performing well till the three clocks in — the first — failed some months back.

First Published: Sat, June 10 2017. 16:00 IST
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