A Constellation Is Only as Strong as Its Spares: What NavIC's Collapse Teaches India

NavIC Did Not Fail Because It Was Badly Designed. It Failed Because It Was Not Replenished. Here is

what a navigation satellite actually does: it broadcasts the exact time. A receiver on the ground compares the time each signal was sent with when it arrived and because radio waves travel at the speed of light, that gap gives a distance.

With signals from several satellites, the receiver works out where it is. Light covers about 30 cm in a billionth of a second, so even a tiny timing error turns into a large position error. That is why every navigation satellite carries atomic clocks and why the clocks matter more than almost anything else on board.

How a Working System Stopped Working

NavIC was designed as a seven-satellite constellation covering India and about 1,500 km around it. The first satellite, IRNSS-1A, went up in 2013 and enough satellites to give a position were in orbit by 2015. Then several things went wrong at once.

First, the clocks. The first-generation satellites carried imported rubidium atomic clocks and their failures disabled several satellites. A navigation satellite without a working clock is, for positioning purposes, switched off.

Second, the replacements. IRNSS-1H, meant to replace IRNSS-1A, never reached orbit because the PSLV's heat shield did not separate in 2017. NVS-02 reached a transfer orbit in 2025, but its propulsion system could not raise it to its final position.

Third, time itself. Most of the original satellites have now passed their 10-year design life. Of the 11 navigation satellites ISRO launched before NVS-03, six have failed. Earlier in 2026, the government reportedly told Parliament that the constellation was no longer providing positioning data.

The Missing Piece Nobody Saw: Receivers The CAG's 2018

report found that work on user receivers, such as chips for phones, began only in 2017, four years after the first satellite went up. Satellites were spending their limited lives transmitting signals that very few devices could use. A navigation system is three things working together: satellites in orbit, ground control and receivers in people's hands. India built the first and second faster than the third.

What NVS-03 Fixes and What It Cannot

The second-generation satellites address two of the weak links. They carry indigenous rubidium atomic clocks built by the Space Applications Centre in Ahmedabad, removing dependence on imported clocks. They also add the L1 frequency to the existing L5 and S bands.

L1 is the band GPS mainly uses, so adding it lets low-power, single-frequency chips in phones and wearables use NavIC alongside GPS. What NVS-03 cannot fix by itself is pace. A constellation is like a relay team that needs a reserve runner ready when anyone stumbles.

India had none. Each satellite now has a 12-year life, but unless replacements are built and launched before old ones fail, the system will degrade again.

Where India Stands India is

one of a small group of countries with its own regional system; Japan's QZSS is another. China built BeiDou in stages, regional first and global later, keeping its constellation replenished throughout. For India, the test is no longer whether it can build a navigation satellite. It is whether it can keep enough of them working at once.

Why This Matters for the Exam

Strategic autonomy in navigation is not a single launch. It is a supply chain of clocks, rockets, spares and receivers. NavIC shows that weakness in any one link can switch the whole system off.