ISRO Launches GSLV-F18 to Boost Aging NavIC Satellite Network

UPDATE - follow-up to ISRO set to launch GSLV-F18 carrying navigation satellite NVS-03 | LIVE: ISRO launched its third space mission of 2026, carrying the 2,250-kg NVS-03 satellite into orbit aboard the GSLV-F18 rocket from the Satish Dhawan Space Centre in Sriharikota. The mission aims to revive India's aging NavIC navigation satellite constellation. NavIC serves as India's indigenous alternative to global systems like the U.S. GPS, Russia's GLONASS, and China's BeiDou. Around 18 minutes and 40 seconds after liftoff from the Second Launch Pad, the rocket deploys the satellite into its initial Geosynchronous Transfer Orbit. ISRO then uses onboard thrusters to raise it to its final orbit.

Satellite Details

NVS-03 features an indigenous atomic clock alongside procured ones. It also includes the L1 signal to join the existing L5 and S-band signals for better navigation services. The launch follows long gaps between previous missions, with NVS-01 in May 2023 and NVS-02 in January 2025 marking a 19-month gap, and a 20-month gap before NVS-03. ISRO also faced setbacks with three failures in six missions between January 2025 and January 2026. Only three of the 11 constellation satellites currently perform primary functions, including aging first-generation satellites IRNSS-1B and IRNSS-1I, and second-generation satellite NVS-01, while NVS-02 suffered engine failures. Restoring NavIC to minimum capacity needs at least two more satellites, NVS-04 and NVS-05, while six to seven satellites are needed for long-term stability.

Context

Satellite navigation systems require multiple active spacecraft in orbit to maintain uninterrupted positioning and timing services for civilian and military users. Agencies often maintain extra backup capacity to ensure continuous coverage even if individual units stop working over time.