GSLV-F18 Put NVS-03, the Third Next-Generation NavIC Satellite and One Carrying an Indigenous Atomic Clock, in Orbit on 30 October 2026, and Its Own Engine Fired the Next Day to Begin the Climb

ISRO’s GSLV-F18 lifted off from the Second Launch Pad at Sriharikota at 23:51 IST on Friday 30 October 2026 and, about 18 minutes later, released the NVS-03 navigation satellite into a transfer orbit, ISRO and the Press Trust of India report. NVS-03 is the third satellite of the next-generation series for NavIC, India’s regional navigation system, and ISRO says it carries an indigenous atomic clock along with procured ones. At 16:48 IST on 31 October the satellite fired its own engine for 2,174.8 seconds, the first of the burns that will take it to its working slot.

What ISRO says happened on launch night

ISRO’s mission page says GSLV-F18 placed NVS-03 in a geosynchronous transfer orbit, a stretched ellipse that the satellite then has to round out with its own engine. A separate ISRO update gives the orbit it was injected into as 170.3 km by 38,080 km. The mission brochure had planned 170 km by 37,023 km, tilted 20.75 degrees to the equator, so the high point came out about 1,000 km above the plan. ISRO does not comment on the difference on the pages read for this article.

PTI, which reported from Sriharikota, says the countdown ran 24 hours and that all three stages worked, including the cryogenic upper stage, which burns liquid hydrogen with liquid oxygen. ISRO’s Chairman, V. Narayanan, said the vehicle had “successfully and precisely” injected the satellite, according to The Hindu. The Prime Minister wrote on X that the mission “marks an important step in strengthening NavIC, our indigenous satellite navigation system.”

The rocket and the 56-day gap

GSLV-F18 was the 20th flight of the Geosynchronous Satellite Launch Vehicle. The brochure describes a vehicle about 50 m tall with a lift-off mass of about 420 tonnes: a solid-fuel first stage with four liquid-fuel strap-on boosters, a liquid-fuel second stage and the cryogenic third stage, under a 3.4 m metallic nose fairing.

The previous flight, GSLV-F17 with the EOS-05 imaging satellite, left Sriharikota on 4 September 2026. Narayanan said the 56 days between the two were the shortest gap yet between successive GSLV missions, The Hindu and VARINDIA both report. The Hindu counts GSLV-F18 as ISRO’s third launch of 2026. The first, PSLV-C62 in January, was a failure by The Hindu’s account; ISRO’s mission page for it says the vehicle met an anomaly at the end of its third stage.

What NVS-03 carries

ISRO describes NVS-03 as the third satellite of the next-generation navigation series, built to keep the older IRNSS satellites’ services going. It adds a signal called L1 to the L5 and S signals the first-generation satellites already send. Coverage stays as before: the Indian landmass and a region reaching 1,500 km beyond India’s boundary.

On weight, the sources differ. ISRO’s brochure gives the payload mass as about 2,250 kg, the figure the Chairman used and The Hindu and VARINDIA repeat. PTI gives 2,232 kg. ISRO’s own page for NVS-01 in 2023 gives “about 2232 kg” for that earlier satellite, which may be where the PTI number came from, though no source says so.

The first burn, and why it is watched

Two of the series’ earlier flights carry the history that makes the 31 October burn worth reporting. NVS-01 flew on 29 May 2023 as the first second-generation satellite. NVS-02, launched on 29 January 2025, reached its transfer orbit of 170 km by 37,785 km but could not raise itself, because the drive signal never reached the pyro valve on the oxidiser line of its engine, an Apex Committee concluded in a note ISRO published on 25 February 2026. The committee’s most likely cause was at least one contact in each of the main and backup paths of a connector coming loose, and it recommended more redundancy in pyro systems.

For NVS-03, ISRO’s update of 31 October says the planned first manoeuvre was completed at 16:48 IST, about 17 hours after lift-off, using the satellite’s Liquid Apogee Motor. The estimated orbit afterwards is 5,477.6 km by 37,833.4 km, which means the low point rose from 170 km to roughly 5,478 km. ISRO reports the satellite health as normal. PTI reported that ISRO flew the satellite with its pyro valves already open; ISRO’s mission and manoeuvre pages do not describe the valve arrangement.

ISRO says more manoeuvres are planned “in the coming days” to place NVS-03 in geostationary orbit at 111.75 degrees East. PTI gave a different longitude, 32.5 degrees East, which does not match ISRO’s own page. As of 2 November 2026, ISRO’s home page lists one manoeuvre update for NVS-03.

Why the count of four matters

A position fix needs signals from four satellites, and the Press Information Bureau set out where NavIC stood on 29 July 2026, in a Lok Sabha reply from the Minister of State for Space. After IRNSS-1F finished its 10-year design life, three satellites were providing positioning, navigation and timing: IRNSS-1B, IRNSS-1I and NVS-01. The reply says that gives no standalone positioning, while the timing service works, and that the armed forces use NavIC alongside other satellite systems. It adds that NVS-03 was ready for launch and that NVS-04 and NVS-05 were in an advanced stage of realisation.

ISRO’s page on IRNSS-1F says its procured atomic clock stopped working on 13 March 2026, though the satellite can still send one-way broadcast messages. The NavIC explainer on tuput covers how the system is laid out and what it is used for, and how GPS works explains why four satellites are the minimum.

Narayanan said that with NVS-03 the constellation will have four working satellites and the country’s positioning services will be restored, VARINDIA reports. That depends on the satellite finishing its climb and passing its tests, which ISRO has not yet announced.

The clock claim, as sources put it

ISRO’s pages say NVS-03 carries an indigenous atomic clock along with procured clocks. They do not say how many Indian-built clocks fly on it, or that it is the first. ISRO’s NVS-01 page says an indigenous atomic clock was to fly for the first time on that 2023 satellite.

VARINDIA reports Narayanan as saying two Indian-made atomic clocks were already operating in space and a third had now gone up on NVS-03. The Hindu, like ISRO, says only that the satellite carries an indigenous clock. The count of three therefore rests on the Chairman’s remarks as VARINDIA reports them, and ISRO’s pages do not give it.

What is still ahead

ISRO has the remaining orbit-raising burns to complete, and the navigation payload still has to be switched on and tested before NVS-03 counts as a fourth working NavIC satellite. The Hindu reports a design life of 12 years for the satellite once it is in service.