Context:

• 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.

Source:TH