Is NavIC setback a concern for India’s national security and defence preparedness?

Parliament has now placed on record a development with direct consequences for India's military strength. India’s navigation constellation, NavIC, has fallen below the minimum number of satellites needed to fix a position. Only three satellites are presently sending usable Positioning, Navigation and Timing data. The system can no longer stand alone as a fully sovereign Indian capability.

Interestingly, NavIC was never built merely as a convenience for finding a restaurant on a map. It was built as a strategic military asset. “In peacetime, Indian forces freely use the American GPS, Russian GLONASS, European Galileo and Chinese BeiDou. These work well as long as relations remain friendly. In war, that changes completely. Signals can be restricted over a particular region, deliberately weakened, or jammed and spoofed. Jamming means drowning the signal with noise. Spoofing is more dangerous; a fake signal fools your receiver into believing it is somewhere else. An Indian system covering the whole country and 1,500 kilometres beyond our borders was designed to remove this dependence,” pointed out defence and space analyst Girish Linganna.

The present shortfall began with the failure of the atomic clock on IRNSS-1F. This satellite was launched in March 2016 and has completed its planned ten-year life. But why should a clock decide whether navigation works? Because satellite navigation is really a game of time, not distance.

“Each satellite keeps broadcasting a signal. A receiver on the ground, in an aircraft or inside a guided weapon measures how long that signal took to arrive. That tiny time gap is multiplied by the speed of light to get the distance. If the onboard clock drifts even by one millionth of a second, the calculated position can be wrong by hundreds of metres. In military operations, such an error is simply unacceptable,” added Linganna.

Union Minister of State for Space Dr Jitendra Singh told Parliament in writing that at least four working satellites are needed for basic positioning. Three satellites can roughly place you in three-dimensional space. The fourth corrects the clock error inside your own receiver, because ordinary receivers cannot carry atomic clocks. Without that fourth signal, the mathematics simply does not close. At present, only IRNSS-1B, IRNSS-1I and NVS-01 deliver full services. The rest of the constellation is limited or no longer giving reliable position data.

For the armed forces, the immediate operational impact is limited. Almost every modern military receiver is multi-constellation, meaning it listens to several satellite systems at once. Soldiers, ships, aircraft and weapon systems keep working by combining the remaining NavIC signals with foreign ones. Daily navigation, targeting and troop movement go on without visible disruption. What has been lost is the purely Indian option—the confidence of operating even if foreign signals are denied.

That distinction matters greatly in a high-intensity conflict. “Precision-guided munitions, artillery fire-control, special forces in hostile territory, naval navigation across the Indian Ocean Region and coordinated air operations all depend on a trusted national source of position and time. Network-centric warfare, where every unit is digitally linked, demands even sharper timing. Secure communications, electronic warfare systems, radar networks and data links must stay synchronised to the microsecond. Here there is good news. NavIC's timing service works normally and still supports these critical functions. Its emergency messaging also remains available, a useful extra channel for coastal and maritime security,” explained Linganna.

Even so, the loss of independent positioning removes a layer of safety defence planners counted upon. Adversaries have already shown they can interfere with foreign satellite signals. A system under full Indian control was meant to be our insurance against exactly that. Until four or more healthy satellites are working, that insurance is thinner than intended.

Recovery is already under way. The next satellite, NVS-03, is ready for launch. NVS-04 and NVS-05 are in advanced development. These second-generation spacecraft carry atomic clocks developed inside India. Earlier satellites used imported clocks, a weakness that has hurt the constellation more than once. Indian-made clocks reduce that dependence and make the system easier to sustain. The moment one more satellite joins, NavIC crosses the critical mark of four and regains independent positioning.

A navigation constellation is not a monument built once and admired forever. It is a living system that needs continuous replenishment. Major powers retire old satellites on schedule and induct new ones before gaps appear. India has built the foundation of NavIC successfully. Sustaining it now matters just as much as creating it. Until the next satellite is operational, our forces will keep relying on multi-constellation receivers. Closing that gap quickly is both a technical and a strategic priority.