NavIC's operational status has repeatedly been hit by satellite-level failures. Explain the technical and institutional measures ISRO has taken to make the NVS series more reliable.

NavIC needs at least four working satellites to give positions on its own. It has fallen short of that because of two kinds of failure. Ageing first-generation satellites have lost their bought-in atomic clocks; IRNSS-1F's clock stopped on 13 March 2026 [3]. The second-generation NVS-02 was left stuck in a 170 × 37,785 km transfer orbit in 2025 [2]. ISRO has responded with engineering fixes and new institutional checks.

Technical measures

• Pre-opened pyro valves: NVS-03 flew with three pyro valves already open. This takes the valve-firing signal, the step that failed on NVS-02, out of the flight sequence [1].
• Removing a shared weak point: NVS-02's main and backup firing signals ran through one connector, and a single loose contact cut both [2]. The Apex Committee's fixes to the pyro-firing system were first tested on CMS-03 (November 2025), where they worked as planned [2].
• Indigenous atomic clock: NVS-01 carried India's first home-built atomic clock [4]. It replaces imported clocks like the one that failed on IRNSS-1F [3].
• Atomic Clock Monitoring Unit (ACMU): Built by SAC, it produces the satellite's 10.23 MHz master timing signal. It also keeps checking the standby clock against the active one, so ISRO can switch to the standby if the active clock fails [5].

Institutional measures

• Formal failure analysis: An Apex Committee ran simulations. It traced the NVS-02 failure to a loose connector contact in both the main and backup paths [2].
• Public disclosure: ISRO published the root cause in February 2026 [1][2]. This opened its work to outside scrutiny, though about a year after the failure.
• Independent review before the next launch: A national committee led by former ISRO chief A.S. Kiran Kumar approved the open-valve design only after vibration and shock tests [1].
• Faster replacement: NVS-04 and NVS-05 are planned within about 5 and 10 months [1]. They are meant to refill the constellation as first-generation satellites retire [3].

With four satellites now active [1], NavIC is back at exactly the minimum it needs. Taken together, these steps move ISRO from fixing one faulty valve towards designing out shared weak points. Next, ISRO should treat NVS-04 and NVS-05 as spares in orbit rather than the bare minimum. It should also apply the Apex Committee's lessons to every critical connector. Together, these steps would give India reliable positioning, navigation and timing, in line with Atmanirbhar Bharat and strategic autonomy.