India’s indigenous navigation system NavIC has dropped below the minimum operational threshold, with only three satellites currently functional, meaning standalone positioning services are unavailable. 

Timing services remain active, but restoring the constellation is critical to reduce reliance on foreign systems.

The government has informed Parliament that NavIC, officially known as the Indian Regional Navigation Satellite System (IRNSS), is presently unable to provide standalone positioning services.

At least four operational satellites are required to independently determine a user’s position, but only three remain active: IRNSS-1B, IRNSS-1I, and NVS-01. This shortfall follows the end of IRNSS-1F’s mission life, which has left the constellation below the minimum requirement.

While NavIC’s timing services continue to function, the absence of sufficient satellites means that users cannot rely solely on NavIC for navigation. Instead, NavIC signals are currently integrated into a multi-constellation environment alongside GPS, Galileo, and GLONASS, ensuring that users do not face immediate security or operational vulnerabilities.

However, this hybrid reliance underscores India’s dependence on foreign infrastructure for critical navigation and timing services.

The failure of IRNSS-1F’s atomic clock marked a significant setback. Atomic clocks are essential for precise Positioning, Navigation and Timing (PNT) services, as even minor timing errors can cause large inaccuracies in determining position.

IRNSS-1F had already completed its planned ten-year mission life before its final clock failed, leaving the system unable to generate navigation signals. Although the satellite remains in orbit, it now only supports limited messaging services for disaster management and societal applications.

India has launched eleven satellites since 2013 to establish and maintain the NavIC constellation. Several first-generation satellites have lost navigation capability due to failures in imported rubidium atomic clocks.

The operational load now rests on IRNSS-1B, IRNSS-1I, and NVS-01, the latter being the first of the second-generation NavIC satellites launched in May 2023. Unfortunately, the NVS-02 mission suffered propulsion issues and could not reach its intended orbit, further delaying the restoration of full service.

ISRO is working to rebuild the constellation with upcoming launches of NVS-03, NVS-04, and NVS-05. These satellites are designed to provide accurate position, velocity, and timing services across India and up to 1,500 kilometres beyond its borders.

Civilian users can expect accuracy better than ten metres once the constellation is restored. The expansion of NavIC is also crucial for strategic applications, including defence, disaster management, and secure communications.

Despite the current shortfall, NavIC has already demonstrated significant utility. Over 10,400 locomotives use NavIC for real-time train tracking, while more than 40,000 fishing vessels are equipped with NavIC receivers for emergency alerts and navigation support.

Mobile handset manufacturers have also integrated NavIC compatibility into over 60 models, reflecting growing commercial adoption. The system provides critical services such as cyclone and tsunami warnings, potential fishing zone advisories, and international maritime boundary alerts.

Restoring NavIC’s full constellation is vital for India’s long-term strategic autonomy. Indigenous navigation capability reduces dependence on foreign systems, strengthens national security, and supports emerging technologies such as autonomous vehicles, precision agriculture, and resilient communication networks.

The government and ISRO are prioritising the launch of new satellites to ensure that India regains full standalone navigation capability in the near future.

Agencies