The Indian Space Research Organisation (ISRO) achieved a major milestone on Friday by successfully launching EOS-05, an advanced Earth observation satellite designed to operate from a geosynchronous orbit and provide high-value data for national applications.
The 2,367-kg satellite was injected into its designated sub-geosynchronous transfer orbit around 18 minutes after liftoff aboard the GSLV-F17 rocket from the second launch pad at the Satish Dhawan Space Centre in Sriharikota.
The mission marks ISRO’s first successful launch of 2026 and represents a significant step in the country’s Earth observation capabilities. Unlike most Earth observation satellites that operate in low Earth orbit, EOS-05 is intended to be positioned at an altitude of about 36,000 km, where its orbital period will correspond with the Earth’s rotation.
The satellite has been described by ISRO scientists as an “eye in the sky” because of its ability to provide near-real-time imagery. Its data is expected to support applications such as agriculture, disaster management and other national requirements.
The successful mission also marks a significant achievement for the GSLV programme. Weighing 2,367 kg, EOS-05 is the heaviest satellite ever launched by the GSLV and the heaviest payload the vehicle has placed into a geosynchronous transfer or sub-GTO orbit.
ISRO Chairman V Narayanan announced the successful completion of the mission, saying the GSLV-F17 had precisely injected the EOS-05 satellite into its intended orbit.
The launch was the 107th from Sriharikota and the 19th mission of the GSLV. Officials noted that the launch vehicle’s payload capacity has increased considerably since the first GSLV mission, which carried a 1,536-kg satellite.
Following the separation of the satellite, ISRO confirmed that its systems were functioning normally and that the solar panels had been deployed successfully. The agency will now carry out a series of orbit-raising manoeuvres to move EOS-05 to its final geosynchronous position.
Mission Director Thomas Kurien said the satellite featured a specialised configuration capable of near-real-time imaging and described it as the heaviest satellite launched by the GSLV into a GTO or sub-GTO orbit.
Project Director (Satellite) Imteyaz Ahamad said EOS-05 was a complex satellite equipped with multi-band capabilities, making it distinct in terms of its configuration and functions.
The launch followed a 27-hour countdown that began at 11.30 pm on Wednesday. The GSLV lifted off at 2.55 am on Friday from the second launch pad at the Satish Dhawan Space Centre.
Despite the pre-dawn timing and rain, a large number of spectators gathered at the spaceport to witness the launch. The GSLV-F17 is a three-stage, 51.7-metre launch vehicle powered by a cryogenic upper stage. It has a lift-off mass of about 420.5 tonnes and carried the EOS-05 satellite inside its nose cone.
The mission also has significance in the wake of the unsuccessful GSLV-F10/EOS-03 mission in 2021. That mission was aborted about 307 seconds after liftoff following an anomaly in the Cryogenic Upper Stage. A subsequent investigation identified the upper-stage anomaly as the cause of the failure.
Friday’s success came nearly eight months after ISRO’s previous launch and followed the failure of the PSLV-C62 mission on January 12. The PSLV-C62, carrying 16 satellites, failed to place its payloads into the intended orbit after an anomaly occurred in the rocket’s third stage.
With EOS-05 now successfully placed in its initial orbit, ISRO is set to proceed with the next phase of the mission to position the satellite in its operational geosynchronous orbit.