Failure of atomic clock cripples ISRO’s NavIC system

The past atomic timepiece aboard the Indian Space Research Organisation’s (ISRO) Indian Regional Navigation Satellite System (IRNSS)-1F satellite has failed, ISRO has said successful a statement. This further weakens the country’s indigenous ‘GPS’ system, informally called NavIC.

Atomic clocks are captious to satellites being capable to connection positional, navigational, and timing services. Since the archetypal of the 8 satellites successful the IRNSS strategy were launched betwixt 2013-2018, the authorities has encouraged Indian enterprises, including machine manufacturers and physics goods having timing services, to trust connected NavIC for determining the Indian Standard Time. 

Currently, the U.S.’s Global Positioning System (GPS), with its 30 outer systems, is the notation modular for specified purposes.

“On 13th March 2026, the procured on-board atomic timepiece stopped functioning. However, the outer volition proceed to relation in-orbit for assorted societal applications to supply 1 mode broadcast messaging services. IRNSS-1F outer launched successful March 2016 has completed its plan ngo beingness of 10 years connected 10th March 2026,” ISRO said successful a connection connected its website precocious connected Friday (March 13, 2026).

Nine IRNSS satellites person been launched since 2013. Eight of them reached their intended orbit. The past of this constellation of satellites (IRNSS-1I) was launched successful 2018. While equivalent American, Chinese and European systems supply planetary positioning services, NavIC is expected to bash truthful lone wrong India and wrong a radius of 1,500 km. This is, however, viewed much arsenic a autumn backmost strategy successful lawsuit of aboriginal planetary conflicts successful which India is denied entree to these overseas constellations.

In July 2025, ISRO revealed via a Right to Information petition that 5 of the NavIC satellites were wholly defunct, with each 3 of clocks successful each outer not working. In 1 of the 3 satellites with functioning atomic clocks, 2 of the 3 clocks had failed.

The atomic clocks successful this constellation of satellites were imported by ISRO from SpectraTime, a Switzerland-based shaper of precocious precision atomic clocks. Four moving satellites could beryllium relied upon for providing positional and navigation services, the Union Minister for Space Jitendra Singh has said successful Parliament. With the nonaccomplishment of the IRNSS-1F’s clock, their fig is down to three.

For the adjacent bid of satellites that volition regenerate the impaired and ageing fleet of IRNSS satellites — 2 of the 3 being utilized person passed their rated support beingness of 10 years though it’s imaginable for these systems to relation beyond — ISRO has decided to instal indigenously developed rubidium clocks.

One replacement satellite, the NVS-01 launched successful May 2023, hosts an indigenously developed rubidium (atomic) clock. The second, the NVS-02 satellite, launched successful January 2025, failed to scope its intended orbit.

ISRO had earlier said that it would beryllium launching astatine slightest 3 satellites by the extremity of 2026 to regenerate defunct and ageing satellites.