NavIC satellite loses its atomic clock: What this means for India’s bid for its own GPS

NavIC satellite loses its atomic clock: What this means for India’s bid for its own GPS

Atomic clocks are key for satellites being able to provide positioning data that is used for applications such as navigation of vehicles, mapping and surveying, and even planning large constructions with accuracy.

The Indian Space Research Organisation (ISRO) on Friday (March 13) informed that the atomic clock of one of the five remaining satellites that were still providing this data stopped working — meaning positioning data from the satellite IRNSS-1F was also lost.

"IRNSS-1F satellite launched in March 2016 has completed its design mission life of 10 years…On 13th March 2026, procured on-board Atomic clock stopped functioning. However, the satellite will continue to function in-orbit for various societal applications to provide one way broadcast messaging services," the space agency said.

Atomic clocks are key for satellites being able to provide positioning data that is used for applications such as navigation of vehicles, mapping and surveying, and even planning large constructions with accuracy.

Importantly, the NVS-02 — launched in January 2025 to replace one of the older satellites in the constellation — was also not able to reach its final orbit and thus provide positioning data.

What is the IRNSS — also known as NavIC — and how has the satellite navigation system fared so far? We explain.

What is IRNSS or NavIC?

The Indian Regional Navigation Satellite System (IRNSS) — also referred to with the operational name of Navigation with Indian Constellation (NavIC) — was planned to be a seven-satellite system to provide positioning data over the Indian subcontinent and 1500 km around it.

It was designed to be a regional system similar to the American GPS.

With all its satellites functioning, the system was designed to provide location accuracy of around 10 metres over the Indian landmass and surrounding countries.

The NavIC system is designed to be more accurate over India, with the satellites placed directly above the region.

This ensures better availability of signals even in difficult geographical locations than GPS, whose signals are received in India at an angle making it difficult to access in certain areas like valleys and forests.

Also in Explained | What ISRO is doing to boost the use of NavIC, India’s version of GPS

However, the system has been running into troubles since its inception.

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How many satellites in the constellation continue to provide positioning data?

After the successful 2023 launch, the constellation had five satellites that could provide the positioning data: IRNSS-1B, 1C, 1F, 1I, and NVS-01, which is the new generation of NavIC satellites.

Now, the atomic clock on board the IRNSS-1F has also been lost.

Atomic clocks on board some of the initial satellites started failing early on, with replacement satellites planned to keep the system running.

Besides the failing atomic clocks, some of the initial satellites are also aging out.

IRNSS-1A was launched into orbit on July 1, 2013, and the 1B and 1C satellites were launched in the following year.

1A is almost defunct — the failed 1H mission of 2018 was intended to replace this satellite — and the other two are also past their 10-year mission lives.

The last of the first-generation IRNSS satellites was 1I — a replacement for the failed 1H launch — which was launched in August 2018.

The NavIC system is crucial for various applications, including navigation of vehicles, mapping and surveying, and even planning large constructions with accuracy.

The loss of the atomic clock on the IRNSS-1F satellite is a setback for the NavIC system, which is already facing challenges in providing accurate positioning data.

The Indian government has been promoting the use of NavIC, and the loss of the atomic clock on the IRNSS-1F satellite may impact the system's ability to provide accurate positioning data.

The ISRO has planned to launch more satellites to replace the aging ones and to improve the accuracy of the NavIC system.

However, the loss of the atomic clock on the IRNSS-1F satellite is a significant setback for the NavIC system, and it remains to be seen how the ISRO will address this issue.

The NavIC system is crucial for various applications, including navigation of vehicles, mapping and surveying, and even planning large constructions with accuracy.

The loss of the atomic clock on the IRNSS-1F satellite is a setback for the NavIC system, which is already facing challenges in providing accurate positioning data.

The Indian government has been promoting the use of NavIC, and the loss of the atomic clock on the IRNSS-1F satellite may impact the system's ability to provide accurate positioning data.

The ISRO has planned to launch more satellites to replace the aging ones and to improve the accuracy of the NavIC system.

However, the loss of the atomic clock on the IRNSS-1F satellite is a significant setback for the NavIC system, and it remains to be seen how the ISRO will address this issue.