GSLV-F17 places EOS-05, India's first geosynchronous imaging satellite, in transfer orbit
Where it stands
ISRO launched EOS-05 at 2:55 am on 4 September 2026. The GSLV-F17 rocket lifted off from Sriharikota. The rocket placed EOS-05 in its intended sub-geosynchronous transfer orbit. EOS-05 weighs about 2,367 kg. The spacecraft will next move towards its working geosynchronous orbit. ISRO calls EOS-05 India's first imaging satellite designed for that orbit. The high orbit will let one spacecraft repeatedly observe a large area. EOS-05 is an Earth observation spacecraft. The launch was the 19th flight of the Geosynchronous Satellite Launch Vehicle. The successful insertion begins the satellite's in-orbit commissioning phase.
Background
Most Earth imaging satellites use low or sun-synchronous orbits. Low-orbit satellites pass over the same place at intervals. A geosynchronous satellite completes one orbit in the time Earth takes to rotate once. The satellite can therefore observe the same broad region repeatedly. A transfer orbit is only an intermediate path. The spacecraft uses its own propulsion to raise and shape the final orbit. GSLV uses three stages. The GSLV third stage uses liquid hydrogen and liquid oxygen at very low temperatures.
How it developed
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4 September 2026, 2:55 amHow it started
GSLV-F17 lifts off from Sriharikota with the 2,367 kg EOS-05
GSLV-F17 lifted off at 2:55 am on 4 September 2026. The rocket departed from the second launch pad at Sriharikota. The rocket carried the 2,367 kg EOS-05 Earth observation spacecraft.
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4 September 2026, about 18 minutes after lift-offNew fact
Rocket places EOS-05 in the intended sub-geosynchronous transfer orbit
GSLV-F17 placed EOS-05 in its intended orbit after lift-off. The nominal transfer orbit has a 170 km perigee and a 28,934 km apogee. The elliptical path is not the satellite's final working orbit.
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4 September 2026Consequence
EOS-05 becomes India's first imaging satellite for geosynchronous orbit
ISRO describes EOS-05 as a state-of-the-art Earth observation spacecraft. EOS-05 is India's first imaging satellite designed for geosynchronous orbit. The successful insertion starts the spacecraft's journey towards its working orbit.
Why it matters for UPSC
For GS3, separate the launch vehicle from the satellite. GSLV-F17 carried EOS-05. EOS-05 performs Earth observation. Also separate a transfer orbit from the working orbit. The rocket placed EOS-05 in a sub-geosynchronous transfer orbit. The spacecraft must later raise its orbit. For Prelims, remember one distinction. Every geostationary orbit is geosynchronous. A geosynchronous orbit need not appear fixed over one point. A geostationary orbit must be circular and above the equator.
Key terms
Sources (4)
- Indian Space Research Organisation · official · GSLV-F17/EOS-05 mission page4 Sep, 10:50 am
- Business Standard · ISRO launches EOS-05, India's first imaging satellite in geosynchronous orbit4 Sep, 10:50 am
- Akashvani News · official · ISRO successfully launches EOS-05 from Sriharikota4 Sep, 10:50 am
- Indian Space Research Organisation · official · GSLV-F17/EOS-05 mission brochure4 Sep, 10:50 am