Open pyro valves guide today’s crucial NavIC-03 launch by ISRO

At 23:51 IST on October 30, 2026, from the Second Launch Pad at Satish Dhawan Space Centre, Sriharikota, GSLV-F18 will lift off carrying NVS-03, with live coverage from 23:20 IST on ISRO's official online stream. This is the GSLV's twentieth flight, and reports and online discussions suggest ISRO may be trying something new: opening the pyro valves on the ground before liftoff so propellant is ready the moment the engines need it. Think of leaving a tap open rather than trusting a remote switch later. ISRO has not confirmed this; official word is expected after launch.

Above the Earth, the NVS-02 satellite drifts in an orbit it was never meant to keep. Its tanks are full, and its engine is sound, yet it cannot move. Pyro valves, tiny one-time switches that open with a small explosive charge when an electrical signal arrives, never received that signal. Without them, neither the main engine, called the Liquid Apogee Motor, nor the small steering thrusters that keep it correctly oriented could draw fuel and oxidiser. The valves were fitted in pairs as backups, but ISRO's review traced the fault to a disengaged contact in a connector on the oxidiser line, cutting off the main and backup paths at once. A spare offers no comfort when the command itself never leaves the plug.

“The stakes are national. NavIC, earlier called IRNSS, is meant to tell us where we are, like America's GPS, Russia's GLONASS, Europe's Galileo and China's BeiDou. A Parliament reply on 29 July 2026 admitted that only three satellites, IRNSS-1B, IRNSS-1I and NVS-01, deliver position, navigation and timing. Fixing a location without foreign help needs at least four, much as you need several landmarks to place yourself on a map. So NavIC today can still give exact time, but cannot on its own tell you where you stand. Of eleven satellites launched, one has been retired, two never reached their intended orbits, and several offer only one-way messaging, not full navigation. The full design calls for seven,” explained space analyst Girish Linganna.

NVS-03, weighing about 2,232 kg, is the third second-generation satellite. It carries an atomic clock built in India beside clocks sourced abroad, a hard-won point of pride. In 2016, the clocks on IRNSS-1A stopped, and others later faltered; NVS-01, launched in May 2023, became the first Indian navigation satellite with a home-grown clock. Timekeeping matters because a receiver finds its position by measuring how long signals take to arrive, so a whisker of clock error becomes hundreds of metres on the ground. NVS-03 also adds a new L1 signal to the existing L5 and S-band, letting more everyday devices tune in. Its coverage spans India and 1,500 km beyond our borders.

“The rocket stands roughly 50 metres tall and weighs about 420 tonnes at liftoff. Its core is the S139 solid booster, holding 139 tonnes of propellant, flanked by four liquid strap-ons, each with a Vikas engine and about 40 tonnes. The whole first stage separates as one unit. A second liquid stage, powered by Vikas, takes over, and the 3.4-metre nose cover, or payload fairing, is shed once the air thins. The cryogenic upper stage, burning super-cold liquid hydrogen and liquid oxygen, then releases NVS-03 into a long oval path between about 170 km and 37,023 km above Earth. The rocket's job ends there; the satellite's own motor must fire repeatedly to round that oval into a high circular orbit, called geosynchronous, where it keeps pace with the Earth's spin. NVS-02 performed flawlessly to this point; the real test for NVS-03 begins where its sibling fell silent,” remarked Linganna.

Space Minister Dr Jitendra Singh has said the NVS-02 faults have been corrected and the fix successfully tested on CMS-03, also known as GSAT-7R, a 4,410 kg communication satellite lofted by the LVM3 on 2 November 2025 to keep the Indian Navy connected across the Indian Ocean. NVS-04 and NVS-05 are in their final stages, with one more to follow to complete the seven.

Should tonight succeed, India will have four working NavIC satellites, the minimum for independent positioning serving armed forces, railways and highways, power grids and banks, and rescue teams racing towards floods and cyclones. Full recovery still demands that new satellites arrive on time and keep working. But for one night, the hopes of a programme scarred by years of setbacks will ride a column of fire over Sriharikota, carried by engineers who chose to learn from loss rather than be defined by it.