India’s ‘own GPS’, which new ISRO satellite can restore

Why in the News

NavIC, India’s regional navigation system, was designed to give the public location data accurate to 10 metres, but it has stopped providing positioning data at all. The Indian Space Research Organisation (ISRO) is slated to launch NVS-03, its third new-generation navigation satellite, to restore the service after a launch delayed since late 2025.

What is NavIC?

1. What it is: NavIC (Navigation with Indian Constellation), formally the Indian Regional Navigation Satellite System (IRNSS), works like India’s own Global Positioning System (GPS). It covers India and up to 1,500 km around it.
2. Two services: A seven-satellite constellation, costing nearly ₹2,250 crore, was to give an open public service and a more accurate paid restricted service for select users such as the military or large construction projects.
3. Why India built it: GPS signals reach India at an angle, so they are hard to receive in valleys and forests. NavIC was meant to cover the Indian landmass better.
4. How positioning works: A navigation satellite uses atomic clocks to measure precisely how long a signal takes to travel to and from an object on Earth. A satellite whose clocks fail cannot give positions.
5. The takeaway: A sovereign navigation system works only while enough satellites keep working, and India has not kept that number up.

Why did the system stop working?

1. Failure count: ISRO has launched 11 navigation satellites for the system, and six have failed, mostly because of defective imported atomic clocks.
2. Late receivers: A 2018 Comptroller and Auditor General of India (CAG) report found that receivers (chips that read the signals) were developed only from 2017. Orbiting satellites lost years of life waiting for them.
3. Failed replacements: Two replacement satellites never reached their working orbits:
   • IRNSS-1H stayed stuck because the heat shield on the Polar Satellite Launch Vehicle (PSLV) did not open;
   • NVS-02 reached a transfer orbit, but its propulsion system failed to complete the manoeuvres.
4. Ageing fleet: Most of the initial satellites have reached the end of their 10-year mission life. The Centre told Parliament this year that the constellation no longer gives positioning data.

What changes with the second generation?

1. Indigenous clocks: The second-generation NVS satellites, starting with NVS-01, carry indigenously developed atomic clocks with a 12-year mission life.
2. Third frequency: They add the L1 frequency to the existing L5 and S signals. L1 is the band GPS uses most, so NavIC works better alongside other systems.
3. Wearable devices: L1 also lets smartwatches and other devices with low-power, single-frequency chips use NavIC data.
4. Extra checks: More thorough checks aim to prevent a propulsion failure like NVS-02’s.

Challenges

1. Smartphone adoption: Most smartphones still rely on GPS, and NavIC needs chipset support from global manufacturers.
2. Launch and propulsion risk: A single failed launch can leave the constellation short of satellites for years.
3. Clock dependence: Positioning stops when clocks fail, and the system has had no spare satellites ready.
4. Interoperability: NavIC still has to be made fully compatible with other navigation systems worldwide.

Way Forward

1. Spare satellites: ISRO should keep replacement satellites ready so a failure does not halt the service.
2. Receiver support: The Centre should push NavIC-capable chips in phones and vehicle trackers sold in India.
3. Fixed launch schedule: ISRO should complete the remaining second-generation satellites on a published timeline.

Conclusion

NavIC shows that navigation independence needs a steady supply of working satellites and receivers, not just a constellation design. Whether NVS-03 reaches its final orbit and restores positioning data is the immediate milestone.

Back2Basics: Global Navigation Satellite Systems (GNSS)

1. What it is: GNSS is the umbrella term for satellite constellations that provide positioning, navigation and timing.
2. Four global systems: The US’s GPS, Russia’s GLONASS, the European Union’s Galileo and China’s BeiDou cover the whole world.
3. GAGAN: The GPS-Aided GEO Augmented Navigation system, built by ISRO and the Airports Authority of India, improves GPS accuracy over India rather than replacing it.

Matching Previous Year Question

“[2015, GS3, 12 marks] What do you understand by ‘Standard Positioning Systems’ and ‘Protection Positioning Systems’ in the GPS era? Discuss the advantages India perceives from its ambitious IRNSS programme employing just seven satellites.”