A 2,367 kg Satellite Launched on 4 September 2026 Is India's First Imaging Satellite for Geosynchronous Orbit, and Three Engine Burns Had Lifted It to About 35,000 km by 7 September

ISRO’s GSLV-F17 lifted off from the Second Launch Pad at Sriharikota at 02:55 IST on Friday 4 September 2026 (21:25 UTC on 3 September, the date SpaceNews used) and released the 2,367 kg EOS-05 satellite into a transfer orbit about 18 minutes later. ISRO’s mission page calls EOS-05 India’s first imaging satellite from geosynchronous orbit, the band about 36,000 km up where a satellite circles at the pace of Earth’s rotation and so keeps one region in view.

By 7 September, three burns of the satellite’s own engine had taken it from the rocket’s drop-off orbit to an estimated 34,903 km by 35,884 km, according to ISRO’s mission updates. In a post on X, the Prime Minister called the launch “yet another outstanding achievement by ISRO” and said the growing partnership between ISRO and Indian industry was adding strength and scale to the space programme.

What the GSLV flew and what it carried

This was the 19th flight of the Geosynchronous Satellite Launch Vehicle, and, ISRO’s chairman said, the 107th launch from Sriharikota, The Week reported. ISRO’s brochure gives the vehicle as three stages, 51.7 m tall, with a lift-off mass of 420.5 tonnes under a 4 m composite nose fairing. A solid motor and four liquid-fuelled strap-on boosters form the first stage, a liquid-fuel stage follows, and the third, called CUS15, burns liquid hydrogen and liquid oxygen with 15 tonnes of propellant. The history of that cryogenic engine, which India had to build after a Russian sale was frozen in 1993, is told in India’s cryogenic engine saga.

The Week and DT Next both call EOS-05 the heaviest satellite the GSLV has carried. The mission director said it was the heaviest satellite the rocket had put into a geosynchronous transfer orbit or the lower sub-geosynchronous version of it, Outlook reported. According to The Week, the chairman said the first GSLV flight carried 1,536 kg.

Planned orbit, per the brochure: 170 km by 28,934 km, tilted 19.28 degrees to the equator. DT Next reported the achieved orbit as 171 km by 31,026 km and said the chairman told reporters the high point was above what had been expected. Both figures describe the rocket’s work only. The satellite had to do the rest of the climb.

Three burns to the final slot

Three short ISRO mission updates record the climb. On 5 September the engine fired for 5,406.4 seconds, finishing at 20:19, and the estimated orbit became 20,000 km by 31,129 km. On 6 September a 338.9 second burn, completed at 19:00, raised the high point to an estimated 35,786 km. On 7 September a 1,247 second burn, completed at 20:57, lifted the low point, and ISRO estimated the orbit at 34,903 km by 35,884 km. Each page says the satellite’s health is normal.

The first page names the target as the geosynchronous slot at 85.5 degrees East longitude. None of the updates I read says when the satellite reached that slot or when it will start imaging.

What a satellite that stays over India can see

Most Earth observation satellites fly a few hundred kilometres up and pass over a place briefly before returning on a later orbit. Open magazine’s report on the launch describes the trade: a satellite at geosynchronous height gives up fine detail but can watch the same broad region again and again. It also notes that clouds block visible and infrared cameras from either height.

ISRO’s brochure says only that EOS-05 is a state-of-the-art Earth observation spacecraft. Reports of the launch supply the imaging figures. DT Next and UNI give about 42 metres of resolution, selected fields revisited about every five minutes and the whole Indian landmass about every 30 minutes, in multispectral and hyperspectral bands under cloud-free conditions. Multispectral means several wide colour bands, and hyperspectral means many narrow ones. Open magazine adds that the bands run from visible to short-wave infrared. These are stated design figures, and the pages I opened do not show measured performance.

DT Next lists the intended uses as weather monitoring, floods, cyclones, forest fires, agriculture, forestry and national security. India already follows storms from geostationary weather satellites, as the piece on how India’s cyclone warnings improved describes. Open magazine says the INSAT series carries meteorological imagers, while EOS-05 is aimed at land and ocean targets. Open magazine contrasts it with the NISAR radar satellite, which sees through cloud and darkness from low orbit but returns to a given place only when its orbit brings it back.

The 2021 loss this follows

GSLV-F10 lifted off on 12 August 2021 at 05:43 carrying EOS-03. Its cryogenic stage deviated from its expected performance 297.3 seconds into the flight, and the onboard computer ended the mission at 307 seconds. The Failure Analysis Committee presented its findings on 24 March 2022. It found that pressure in the liquid hydrogen tank was too low at engine ignition, which starved the fuel booster turbopump, and that the most likely cause was a leak in the tank’s vent and relief valve.

It recommended an active tank pressurisation system, a stronger valve and its plumbing, and more cryogenic-stage readings monitored automatically before clearing a lift-off. The pages I read do not say which of those changes flew on GSLV-F17. Outlook and other outlets describe EOS-05 as the replacement for EOS-03, also known as GISAT-1, and Outlook says EOS-05 carries the name GISAT-1A under ISRO’s newer naming. The F17 mission page uses neither name.

The launch after January

SpaceNews described GSLV-F17 as ISRO’s first launch since a failure in January. ISRO’s page for PSLV-C62, flown from the First Launch Pad on 12 January 2026, says the mission “encountered an anomaly during end of the PS3 stage” and that a detailed analysis had begun. The Week and Onmanorama reported that the rocket, which carried 16 satellites, did not place them in the intended orbit.

What ISRO said comes next

DT Next reported the chairman as saying that the NVS-03 navigation satellite launch is next, that six more satellite launches are planned in the current financial year (April 2026 to March 2027), and that the first uncrewed Gaganyaan spacecraft is being prepared. Outlook, citing Indian Express, said NVS-03 was likely in November. As of 14 October 2026, ISRO’s homepage lists the three orbit-raising updates for EOS-05 and no image release or start date for routine imaging.