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Atomic clocks on indigenous navigation satellite develop snag

Discussion in 'Education & Research' started by Agent_47, Jan 30, 2017.

  1. Agent_47

    Agent_47 Admin - Blog IDF NewBie

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    NavIC, the indigenously built satellite- based positioning system, has developed a technical snag in the atomic clocks on its first satellite.

    In the NavIC, a constellation of seven satellites, one of the three crucial rubidium timekeepers on IRNSS-1A spacecraft failed six months ago. The other two followed subsequently.

    A. S. Kiran Kumar, Chairman of the Indian Space Research Organisation, confirmed the glitch in the clocks but clarified that the satellite was otherwise all right, and the rest of the satellites were performing its core function of providing accurate position, navigation and time. However, without its clocks, the IRNSS-1A “will give a coarse value. It will not be used for computation. Messages from it will still be used.”

    ISRO, he said, was trying to revive the clocks on 1A and readying one of the two back-up navigation satellites to replace it in space in the second half of this year.

    “There are some anomalies in the atomic clock system on board. We are trying to restart it. Right now we are working out a mechanism for operating it,” he told The Hindu .

    He added, “The problem is only with the clock system of one spacecraft. The signals are all coming, we are getting the messages, everything else is working and being used, except the stability portion which is linked to the clock.”

    Mr. Kiran Kumar said a minimum of four working satellites was sufficient to realise the full use of the navigation system”.

    NavIC has 21 atomic clocks on seven spacecraft. “How would the other clocks fare? Would ISRO reconsider the supplier of its atomic clocks? Such questions are not easy to answer. Generally any [space] hardware is an issue. We have to find ways of going around it,” he said.

    The troubled IRNSS-1A spacecraft was put in space in July 2013 and has an expected life span of 10 years. The seventh navigation satellite, IRNSS-1G, was launched in April 2016.

    The satellites of the Rs. 1,420-crore NavIC, short for Navigation with Indian Constellation, and also known as the Indian Regional Navigation Satellite System, give precise information on position, navigation and time (PNT) of objects or persons to users on ground, sea and air.

    The system has a restricted military component.

    Similar glitches

    Mr. Kiran Kumar agreed that the problem on NavIC was similar to the atomic clock glitches that struck the European navigation constellation Galileo.

    On January 18, Jan Woerner, Director General of the European Space Agency (ESA), which is putting up the 26-satellite Galileo system, made their problem public. Galileo has placed 18 spacecraft in space and is now deciding whether it should launch the four satellites as planned this year. He had also said they were in touch with ISRO after nine of their clocks developed snags.

    ESA’s and ISRO’s clocks reportedly come from the same Swiss company.

    http://www.thehindu.com/todays-pape...on-satellite-develop-snag/article17114592.ece
     
  2. Ripcord322

    Ripcord322 Lieutenant FULL MEMBER

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    Where were those clocks from...!?
     
  3. Gessler

    Gessler Lt. Colonel IDF NewBie

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    It's written in the article -

    The company is Spectratime.
     
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  4. bharathp

    bharathp Developers Guild IDF NewBie

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    <sarcasm on> so much for swiss watches huh <sarcasm off>
    two positives:
    1) that the NavIC system is still functional (Redundancy built in)
    2) that the ISRO officials are already working to fix it and have a backup satellite ready

    two negatives:
    1) the cost of reduced utility from that satellite means we cannot fully recoup the investment
    2) If a similar problem was reported by other agencies in using the same clock makers, we should have probably been smarter about it.

    over all - a news to be worried about, but also to have faith on ISRO.
     
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  5. Zer0reZ

    Zer0reZ 2nd Lieutant FULL MEMBER

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    India's native navigation system has developed serious problems with four atomic clocks on the six satellites facing unexplained errors. With these, a total seven out of 21 clocks onboard have shown some difficulties.

    Sources said that more atomic clocks have faced difficulties in providing data which is likely to be compensated with the launch of a replacement satellite in near future. Rubidium atomic clocks were manufactured by the Swiss company Spectracom. However, India's CSIR-NPL has developed and transferred the critical technology of Rubidium atomic clock for space applications to ISRO. A model has been developed at CSIR-NPL and is undergoing further developments at Satellite Applications Center before being integrated into the payload of the IRNSS.
     

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