Bengaluru: India's own satellite navigation system is being rebuilt one launch at a time, and the next attempt comes on Friday night. ISRO will put NVS-03 into orbit on the GSLV-F18 rocket from the Second Launch Pad at the Satish Dhawan Space Centre in Sriharikota at 11.51 pm.
It will be the 20th flight of the Geosynchronous Satellite Launch Vehicle. The roughly 50-metre rocket, with a lift-off mass of about 420 tonnes, will place the approximately 2,250-kg satellite into a geosynchronous transfer orbit with a perigee of 170 km, an apogee of 37,023 km and an inclination of 20.75 degrees.
NVS-03 is the third satellite in ISRO's next-generation navigation series, meant to keep the Indian Regional Navigation Satellite System — now Navigation with Indian Constellation, or NavIC — running. NavIC is designed to provide position, navigation and timing services across India and about 1,500 km beyond the landmass, cutting dependence on foreign systems.
"NVS-03 carries an indigenous atomic clock alongside procured clocks and introduces the L1 signal, in addition to the existing L5 and S signals," ISRO said. The addition is expected to widen compatibility with more user devices.
The launch comes at an awkward moment, with NavIC operating below its minimum requirement. Earlier this year, Union minister Jitendra Singh told Parliament that after IRNSS-1F completed its 10-year mission life, the constellation had three satellites — IRNSS-1B, IRNSS-1I and NVS-01 — for providing positioning services, against a minimum of four needed for basic positioning. The government acknowledged that NavIC "cannot provide standalone positioning service, however timing service is functional".
The trouble has come from ageing satellites, atomic-clock failures and a failed replenishment mission. IRNSS-1F completed its mission life in March 2026, and its procured onboard atomic clock soon stopped working, taking it out of navigation service. The sharper setback was NVS-02, launched on January 29, 2025 on GSLV-F15: the satellite separated and deployed its solar panels but could not perform the orbit-raising manoeuvres. An ISRO apex committee traced the failure to the pyro system, concluding that a drive signal did not reach the pyro valve in the oxidiser line. The panel's recommendations on redundancy have been implemented, the agency said.
A successful launch raises the number of navigation-capable satellites but will not by itself restore full service. The spacecraft must complete orbit-raising, reach its designated slot and be validated. The government has said NVS-04 and NVS-05 are in an advanced stage of realisation.