ISRO NavIC Constellation

Context

NavIC (Navigation with Indian Constellation) or IRNSS is a regional satellite navigation system of India that is aimed at providing precise position and time information. Even so, the system is currently limited in its operational capabilities, with only a limited number of satellites operating in their full capacity as of March 2026. To accomplish its strategic objective of having a strong, autonomous network of navigation, ISRO needs to fix important technical and launching problems prior to the launch of the second generation (NVS) satellites.

Current Status and Core Issues with NavIC

1. Atomic Clock Failures: The most severe loss has been atomic clock failure in rubidium atomic clocks which is essential in determination of accurate locations. There were several first-generation satellites (1A, 1C, 1D, 1E, 1G) that had problems with their clocks. In recent times, IRNSS-1F has lost the last useful atomic clock which made it useless in positioning.
2. Constellation and Replenishment Rates: The rate of degradation of the constellation is higher than the rate of its replacement. A large number of satellites are already experiencing or approaching 10 years of mission life leading to loss of precision.
3. Launch Failures (NVS-02 Setback): The most recent modernization effort (NVS-02 satellite) did not reach its orbit in January 2025 as the propulsion system did not work.
4. Poor Adoption: NavIC-capable receivers cannot compete with GPS regarding their number of applications in civilian consumer devices.

Issues ISRO Must Fix Before Next Launches 

A number of systemic problems should be solved to reinstate the strategic and commercial value of the NavIC prior to the planned release of NVS-03, 04 and 05 later in 2026.

1. Reliability of Indigenous Atomic Clocks

Although ISRO has replaced the imported European clocks with the locally developed Rubidium Atomic Frequency Standards (RAFS), there has been the problem of procurement and stability. To ensure resilience:

• Heightened Redundancy: New satellites will be suggested to have five atomic clocks, as opposed to the former three so that the mission will not fail due to the failure at one point.
• Strict Quality Control: Tough testing is required to get rid of batch defects that have resulted in a series of clocks malfunctioning in the same satellite.

2. Propulsion and Orbital Injection Systems

NVS-02 failed because of a pyro valve fault which blocked the ignition of thrusters to raise the orbit. ISRO must ensure:

• Hardware Integrity: Improved inspection of mechanical parts such as connectors and valves to eliminate electrical failures in space.
• Alternate Strategies: A strong protocol software to be developed that will be used to employ satellites in case they get stuck in unwanted elliptical orbit.

3. Interoperability and User Adoption

The initial generation satellites (IRNSS series) were restricted to L5 and S bands which restricted their applications in commercial smartphones.

• The L1 Band Requirement: All second generation (NVS) satellites should be able to broadcast in L1 frequency, which is globally compatible with GPS and is used in the majority of consumer products.
• Ecosystem Development: India has to hasten the manufacture of NavIC-compatible receivers in order to minimize dependence on foreign chips.

Strategic Significance and Future Outlook

In spite of these difficulties, NavIC is critical to the strategic autonomy of India, including 1,500 km in all directions, and extending to 1,500 km, primarily due to defense, air, sea, and disaster management. NVS series will enhance the lifespan of operations to 12 years and make operations more accurate.

Source: The Hindu

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