ISRO Launches NVS-03: NavIC Gets Back to Four Working Satellites
The Indian Space Research Organisation (ISRO) launched the navigation satellite NVS-03 on 30 October 2026 at 11:51 pm IST. It flew on the GSLV-F18 rocket from the Second Launch Pad of the Satish Dhawan Space Centre, Sriharikota.
GSLV-F18 was the 20th flight of the GSLV rocket. ISRO said the rocket placed the satellite correctly into a Geosynchronous Transfer Orbit (GTO), an oval "parking" orbit from which the satellite climbs up on its own.
NVS-03 weighs about 2,230 to 2,250 kg (sources differ slightly). It will now fire its own engine several times to reach its working slot at 32.5° East in geosynchronous orbit.
It is the third satellite of the second-generation NVS series of NavIC, India's own navigation system. It carries an Indian-made atomic clock along with bought (imported) atomic clocks, and sends L1, L5 and S-band signals.
Before this launch, only three NavIC satellites were working (IRNSS-1B, IRNSS-1I and NVS-01). At least four are needed for a receiver to find its position, so NavIC could give only timing, not standalone positioning. Once NVS-03 is in place and tested, NavIC returns to a four-satellite, standalone service.
NavIC (IRNSS): India's Regional Navigation Satellite System
NavIC is India's own satellite navigation system, like the American GPS but covering only India and the region around it. Its official name is the Indian Regional Navigation Satellite System (IRNSS), and NavIC stands for "Navigation with Indian Constellation". It tells a user their exact position and the exact time. It covers India and an area of about 1,500 km beyond India's borders. Its full design has seven satellites: three in geostationary orbit and four in inclined geosynchronous orbit.
NavIC had fallen to three working satellites after IRNSS-1F's clocks stopped and NVS-02 failed to reach its orbit, so it could not give standalone positions. NVS-03, parked at 32.5°E (the old IRNSS-1F slot), brings the count back to four and restores basic positioning for India.
Atomic Clocks: The Heart of Any Navigation Satellite
An atomic clock keeps time by counting the natural, fixed "ticks" of atoms such as rubidium or caesium. It is so accurate that it drifts by only a tiny fraction of a second over many years. A navigation satellite needs such a clock because a receiver finds its distance from a satellite by measuring how long the signal took to arrive. An error of just one millionth of a second in time can put the position wrong by about 300 metres, because radio signals travel at the speed of light.
Clock failures are the main reason NavIC lost working satellites over the years. NVS-03's mix of Indian-made and procured atomic clocks is meant to keep the satellite giving accurate time, and therefore accurate positions, through its life.
GSLV (Geosynchronous Satellite Launch Vehicle) Programme
The Geosynchronous Satellite Launch Vehicle (GSLV) is an ISRO rocket built to carry heavier satellites of about 2 to 2.5 tonnes into high orbits. It places communication, weather and navigation satellites into a Geosynchronous Transfer Orbit (GTO). From there, each satellite uses its own engine to climb to its final orbit about 36,000 km above the Earth. The current version, GSLV Mk II, has three stages and four liquid "strap-on" boosters.
NVS-03, at about 2.2 tonnes, sits right at the top of what GSLV Mk II can carry to GTO. The rocket did its part by placing the satellite in the right transfer orbit; the satellite's own engine must now finish the climb, the step where NVS-02 failed in 2025.
- NVS-03 launch: 30 October 2026, 11:51 pm IST, Second Launch Pad, Satish Dhawan Space Centre, Sriharikota
- Rocket: GSLV-F18, the 20th GSLV flight; three stages with a cryogenic upper stage
- Satellite mass: about 2,230 to 2,250 kg; first placed in a Geosynchronous Transfer Orbit
- Transfer orbit: perigee about 170 km, apogee about 37,023 km, inclination 20.75°
- Final working slot: 32.5° East (geosynchronous)
- Signals: L1, L5 and S-band; clocks: indigenous plus procured atomic clocks
- NavIC coverage: India plus about 1,500 km beyond its borders
- NavIC design: 7 satellites (3 geostationary + 4 inclined geosynchronous); at least 4 needed for positioning
- Working satellites before NVS-03: 3 (IRNSS-1B, IRNSS-1I, NVS-01)
- NVS series: 5 satellites planned; NVS-01 (2023) worked, NVS-02 (2025) stranded, NVS-03 (2026) third