India’s Navigation with Indian Constellation (NavIC), also called the Indian Regional Navigation Satellite System (IRNSS), had three operational satellites for Position, Navigation and Timing (PNT) services in March and April 2026. The active satellites were IRNSS-1B, IRNSS-1I and NVS-01, while the system required at least four operational satellites for accurate 3D PNT services.
NavIC and IRNSS
NavIC is India’s regional satellite navigation system developed by the Indian Space Research Organisation (ISRO). It provides PNT services over India and the surrounding region, and it is designed as an independent navigation system for civilian and strategic use.
Operational Satellites and Design Life
- IRNSS-1B was launched in April 2014 and has crossed its intended 10-year design life.
- IRNSS-1I was launched in April 2018 and was nearing the end of its service life in 2026.
- NVS-01 was launched in May 2023 as the first second-generation NavIC satellite.
Atomic Clock Failure
The reduction to three operational satellites followed the failure of the atomic clock on IRNSS-1F on 13 March 2026. IRNSS-1F had completed its 10-year design life on 10 March 2026. Atomic clocks are essential components in navigation satellites because they provide precise time signals for PNT calculations.
Second-Generation NavIC Satellites
NVS-01 carries an indigenous rubidium atomic clock and supports the L1 band, which is compatible with smartphones. NVS-02 was launched in January 2025, but it failed to reach its intended orbit because of an electrical fault in its propulsion system.
Satellite Failures in the Constellation
Six of the 11 NavIC satellites launched so far have experienced atomic clock failures. Several of these failures were linked to imported clocks, while NVS-01 uses an indigenous clock.
Replacement Plan
A Parliamentary Committee report presented on 25 March 2026 stated that partial revival of NavIC may take 15 to 18 months. The replacement satellites NVS-03, NVS-04 and NVS-05 were expected to be launched within that period.
Exam-Relevant Facts
NavIC is India’s regional satellite navigation system and is part of the broader class of Global Navigation Satellite Systems (GNSS). PNT services are used in navigation, timing synchronisation, disaster management, agriculture and defence applications.
Last Modified: April 24, 2026