ISRO’s clock to prop up India’s own GPS


  • Time is running out for the seven-satellite Indian Regional Navigation Satellite System (IRNSS), also known as NavIC (Navigation in Indian Constellation).
  • NavIC, whose seventh satellite was launched in April 2016, was expected to provide India a satellite-based navigation system independent of the U.S.-controlled GPS (Global Positioning System).
  • But India’s own ‘regional GPS’ is yet to become officially operational owing to repeated failures of the atomic clocks on the satellites.

Facts for Prelims:

  • NavIC is meant to give Indian civil and military users reliable location and time information, for which the performance of the atomic clocks is critical.
  • The rubidium atomic clocks from Europe started failing on the first navigation satellite, IRNSS-1A, around 2016, soon after ISRO put the last and seventh satellite in orbit.
  • Until a few months ago, three more satellites were said to have suffered “one or two dysfunctional clocks” each, while two satellites did not have any problematic clocks.
  • Each satellite carries three atomic clocks, including a standby.
  • ISRO is concerned that if more clocks fail, it may render the ₹1,400-crore fleet a dud in space. NavIC, which will be controlled solely by India, unlike the American GPS or Russian Glonass navigation systems, will be useful as navigation aids for the armed forces.