GSLV places next-generation navigation satellite into orbit

Why in the News

India’s own navigation system NavIC, weakened by repeated atomic clock failures, now has a new satellite in orbit. The Indian Space Research Organisation’s (ISRO) Geosynchronous Satellite Launch Vehicle (GSLV-F18) placed NVS-03 in its intended transfer orbit 18 minutes after lift off. The satellite carries an indigenous atomic clock, an answer to the failures and the missed orbit of the earlier replacement NVS-02 that had left the system degraded.

What is NavIC, and why did it weaken?

1. NavIC: Navigation with Indian Constellation (NavIC) is India’s independent regional satellite navigation system, like a home grown Global Positioning System (GPS). It gives Position, Navigation and Timing (PNT) service in India and about 1,500 km beyond.
2. Role of atomic clocks: A receiver finds its position from the exact time signals take to arrive, so every satellite depends on its atomic clocks. A satellite with failed clocks cannot give a reliable fix.
3. Failure record: Of the 11 satellites launched for the seven satellite system, six have failed, mostly because of defective imported atomic clocks.
4. Latest setback: On 13 March this year the last functioning atomic clock on IRNSS-1F, a satellite of the Indian Regional Navigation Satellite System (IRNSS), stopped working.
5. The takeaway: NavIC’s timing source failed repeatedly, and the system stayed weak until a replacement could be launched.

What did the GSLV-F18 launch achieve?

1. Launch: GSLV-F18 lifted off late on Friday from the second launch pad at Sriharikota and placed the 2,250 kg NVS-03 in the intended geosynchronous transfer orbit, a stepping orbit from which satellites climb to working position.
2. NVS series: NVS-03 is the third satellite of the next generation series meant to provide continuity of services for the IRNSS series, with a mission life of 12 years.
3. Clocks: It carries an indigenous atomic clock along with procured atomic clocks.
4. New signal: It adds an L1 signal to the existing L5 and S signals, widening the services over the same footprint.

Why does NVS-03 matter for NavIC?

1. Civil and defence use: India uses NavIC for civilian and defence navigation on the mainland and beyond, so a working system reduces reliance on foreign satellite services.
2. Indian Standard Time: The Legal Metrology (Indian Standard Time) Rules, 2026 allow NavIC and other approved Indian sources to broadcast official time, a shift away from foreign sources such as GPS for critical infrastructure timing.
3. Indigenous clock: A home built clock reduces dependence on imported clocks whose defects caused earlier failures.

Challenges

1. Launch reliability: Friday’s launch is only the third of the year for ISRO. The PSLV-C62 mission failed in January, and GSLV-F17 succeeded in September.
2. Orbit raising: NVS-02 failed when its propulsion gave out in transfer orbit, so NVS-03 must still prove it can reach its working orbit.
3. Clock dependence: Procured clocks still fly beside the indigenous one, so import risk is reduced, not removed.
4. Incomplete series: NVS-03 is the third of its series, so continuity depends on the remaining satellites reaching orbit and working.

Way Forward

1. Clock qualification: Fly and test the indigenous clock on more satellites until imported clocks become a backup.
2. Pre launch checks: Add checks on propulsion and launch systems for the rest of the series.
3. Wider adoption: Encourage NavIC capable chips in devices and critical infrastructure timing, building on the Indian Standard Time rules.

Conclusion

NVS-03 puts a new satellite in orbit, but NavIC’s recovery is not yet complete. The marker to watch is the satellite reaching its working orbit and switching on its signals, followed by the next launch in the series.

Matching Previous Year Question

“[2018] With reference to the Indian Regional Navigation Satellite System (IRNSS), consider the following statements : 1. IRNSS has three satellites in geostationary and four satellites in geosynchronous orbits. 2. IRNSS covers entire India and about 5500 sq. km beyond its borders. 3. India will have its own satellite navigation system with full global coverage by the middle of 2019. Which of the statements given above is/are correct ? (a) 1 only (b) 1 and 2 only (c) 2 and 3 only (d) None ANSWER: (a)”