Failure of atomic clock cripples ISRO’s NavIC system

The final atomic clock aboard the Indian Area Analysis Organisation’s (ISRO) Indian Regional Navigation Satellite tv for pc System (IRNSS)-1F satellite tv for pc has failed, ISRO has stated in a press release. This additional weakens the nation’s indigenous ‘GPS’ system, informally known as NavIC.

Atomic clocks are essential to satellites having the ability to supply positional, navigational, and timing companies. Because the first of the eight satellites within the IRNSS system had been launched between 2013-2018, the federal government has inspired Indian enterprises, together with laptop producers and digital items having timing companies, to depend on NavIC for figuring out the Indian Normal Time. 

At the moment, the U.S.’s International Positioning System (GPS), with its 30 satellite tv for pc programs, is the reference normal for such functions.

“On thirteenth March 2026, the procured on-board atomic clock stopped functioning. Nevertheless, the satellite tv for pc will proceed to perform in-orbit for numerous societal functions to offer a method broadcast messaging companies. IRNSS-1F satellite tv for pc launched in March 2016 has accomplished its design mission lifetime of 10 years on tenth March 2026,” ISRO stated in a press release on its web site late on Friday (March 13, 2026).

9 IRNSS satellites have been launched since 2013. Eight of them reached their supposed orbit. The final of this constellation of satellites (IRNSS-1I) was launched in 2018. Whereas equal American, Chinese language and European programs present international positioning companies, NavIC is predicted to take action solely inside India and inside a radius of 1,500 km. That is, nevertheless, seen extra as a fall again system in case of future international conflicts during which India is denied entry to those overseas constellations.

In July 2025, ISRO revealed through a Proper to Data request that 5 of the NavIC satellites had been fully defunct, with all three of clocks in every satellite tv for pc not working. In one of many three satellites with functioning atomic clocks, two of the three clocks had failed.

The atomic clocks on this constellation of satellites had been imported by ISRO from SpectraTime, a Switzerland-based maker of excessive precision atomic clocks. 4 working satellites might be relied upon for offering positional and navigation companies, the Union Minister for Area Jitendra Singh has stated in Parliament. With the failure of the IRNSS-1F’s clock, their quantity is down to 3.

For the subsequent collection of satellites that can substitute the impaired and ageing fleet of IRNSS satellites — two of the three getting used have handed their rated shelf lifetime of 10 years although it’s doable for these programs to perform past — ISRO has determined to put in indigenously developed rubidium clocks.

One substitute satellite tv for pc, the NVS-01 launched in Might 2023, hosts an indigenously developed rubidium (atomic) clock. The second, the NVS-02 satellite tv for pc, launched in January 2025, failed to succeed in its supposed orbit.

ISRO had earlier stated that it could be launching at the very least three satellites by the tip of 2026 to switch defunct and ageing satellites.