Three satellites short: ISRO’s NavIC stops navigating

The Centre recently told Parliament something India did not want to hear. Our own satellite navigation system, NavIC, can no longer guide anyone on its own.

After losing positioning data from one satellite in March 2026, the seven-satellite constellation has fallen below the minimum strength needed to fix a location.

NavIC, formally the Indian Regional Navigation Satellite System or IRNSS, was built to give India its own positioning service, covering the entire country and up to 1,500 km beyond our borders.

The idea was simple and strategic. Every time we open a map on our phone, we depend on satellites owned by another country.

In a crisis, that dependence can become a weakness. NavIC was India's answer: our own eyes in the sky, under our own control.

The trouble began with IRNSS-1F, which had been launched in March 2016. ISRO confirmed earlier this year that the satellite had completed its planned ten-year life, and its on-board atomic clock stopped working. “An atomic clock may sound like a small part, but it is the heart of any navigation satellite. Positioning works entirely on time.

A satellite sends a signal, and the receiver in your phone measures how long that signal took to arrive. Multiply that tiny time gap by the speed of light, and you get distance.

If the clock drifts even by a millionth of a second, the location error can run into hundreds of metres. So when the clock dies, the satellite may still be flying, but it can no longer be trusted to tell you where you are,” explained space analyst Girish Linganna.

At present, only three satellites are providing Positioning, Navigation and Timing services—IRNSS-1B, IRNSS-1I and NVS-01.

Union Minister of State for Space Dr Jitendra Singh stated in a written reply in Parliament that at least four working satellites are needed in orbit for basic positioning.

Why four satellites? 

Three satellites can pin down your position in space, but a fourth is needed to correct the clock error inside your own device. Without that fourth signal, the maths simply does not close.

With only three left, NavIC cannot offer independent positioning. Its timing service, however, continues to work normally.

So what happens to ordinary users? 

In practice, almost nothing changes today. This is because nearly every modern receiver is a multi-constellation GNSS receiver. GNSS stands for Global Navigation Satellite System, and your phone quietly listens to several of them at once—the American GPS, Europe's Galileo, Russia's GLONASS, China's BeiDou and, until now, India's NavIC.

The government's reply confirmed that since NavIC was always used alongside these systems, users are not facing any loss of accuracy. Applications built for aviation, shipping, railways and mobile phones will keep working, because those devices can simply lean on the other constellations.

“The real loss, then, is not accuracy. It is independence. Foreign systems are generous in peacetime, but they belong to foreign governments. Signals can be degraded, restricted or switched off over a region during conflict, and that possibility is precisely what pushed India to build NavIC in the first place.

The reply noted that our armed forces still use NavIC signals, but as part of a combined multi-constellation setup. In other words, NavIC is now one voice in a chorus rather than a system we can stand on alone,” added Linganna.

It is also worth remembering what NavIC still does well. It continues to broadcast highly accurate time signals, which quietly run our banking networks, telecom towers and power grids, where operations must stay synchronised to the microsecond.

It can also transmit emergency alert messages a service that has genuinely helped fishermen at sea receive cyclone warnings far from any mobile tower.

What is the alternative?

Recovery is already on the way. The next satellite, NVS-03, is ready for launch, while NVS-04 and NVS-05 are in the final stages of development. The NVS series is a modernised generation carrying indigenous atomic clocks developed in India, which reduces our dependence on imported components—the very failure point that has hurt the constellation repeatedly since its early days.

Once even one more satellite joins, NavIC crosses the magic number of four and stands on its own feet again.

The lesson here is about maintenance, not failure. A satellite constellation is not built once and forgotten. It must be constantly replenished, like a fleet of buses where old vehicles retire, and new ones must roll in on time. India built the system. The task now is to keep it flying.