ISRO Set to Launch EOS-05 Earth-Observation Satellite Aboard GSLV-F17

The Indian Space Research Organisation (ISRO) is preparing to launch its EOS-05 Earth observation satellite, also known as GISAT-1A, aboard the GSLV-F17 rocket from the Satish Dhawan Space Centre in Sriharikota, about 110 kilometres from Chennai. The launch is expected in the early hours of September 4 at 2:55 a.m. IST from the centre's Second Launch Pad, though ISRO has not officially confirmed the date. It will be the 19th flight of India's Geosynchronous Satellite Launch Vehicle (GSLV).

EOS-05 will be India's first imaging satellite to operate from a Sub-Geosynchronous Transfer Orbit (Sub-GTO), an orbit closer to Earth than a full geostationary transfer orbit. The three-stage GSLV-F17 rocket, which uses an indigenous cryogenic upper stage, stands 51.7 metres tall and weighs 420.5 tonnes at liftoff. Carrying a 4-metre-diameter Ogive-shaped composite payload fairing, it will place the 2,367-kilogram EOS-05 spacecraft into an orbit with a perigee of 170 kilometres and an apogee of 28,934 kilometres, inclined about 19.28 degrees, plus or minus one degree, to the equator.

The mission comes nearly five years after ISRO lost its GISAT-1 satellite on August 21, 2021, when the GSLV-F10 rocket carrying it suffered a glitch in its cryogenic upper stage shortly after liftoff.

Once operational, EOS-05 is designed to capture near-real-time images of the Earth in multi-spectral and hyper-spectral bands under cloud-free conditions, to support monitoring of land and the environment. ISRO says the satellite can image a selected area every five minutes and cover the entire Indian landmass every 30 minutes, at a spatial resolution of 42 metres.