Desi satellite to have three improved atomic clocks
Chennai: IRNSS-1H, with three rubidium atomic clocks of an improved design, will replace the first of the seven Indian Regional Navigational Satellite System or NaVIC, when it takes off on board a PSLV from Sriharikota on Thursday. The rubidium atomic clocks, made by Astrium, a European aerospace manufacturer, is meant to provide accurate locational data.
The new satellite is being launched as IRNSS-1A's atomic clocks stopped functioning. However, the satellite will continue to be used for other functions as only the clocks are found to be faulty.
Director of space application centre, Indian Space Research Organisation (Isro), Tapan Mishra said that issues like temperature, rubidium bulb that produce light and electronic power supply resulted in the failure of the atomic clocks installed in IRNSS-1A. Navigation satellites require precise time to measure accurate location. IRNSS-1A was launched on July 1, 2013. Last year, Isro scientists found that all three atomic clocks installed in the satellite stopped.
"We have addressed these anomalies and have improved the design of the clocks installed in the new satellite," he said.
Mishra explained they have to measure the satellite's position at an accuracy of 0.5m and atomic clocks help in determining it.
"The clocks that failed are the first set of clocks we received. We have improved the design in the subsequent satellites. Usually, there is a probability of the clocks failing in the first three-year time frame. Also, we are not the only one who has had problems with the clocks," he said.
Atomic clocks in Glonass, Russia's navigation satellite system and Galileo, the European Union's navigation satellite system have also failed earlier.
Isro had imported 27 sophisticated timekeepers, which run on the element rubidium, for nine satellites of the navigation system. Seven of the satellites are now in orbit and two of them are on standby.
In an earlier launch, Isro chairman Kiran Kumar said the failure of the atomic clocks in one of the seven satellites in orbit, will not affect the performance of the navigation system.
"The original mission was identified with seven satellites and two spare satellites. A minimum of four satellites are required to provide services. We have six fully functional ones. The services from these satellites are available and companies have started building hardware to use these resources," he said.
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