Launch details
The Indian Space Research Organisation (ISRO) is set to launch India's first imaging satellite destined for geosynchronous orbit from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh, on Friday, September 4. The Earth observation satellite, designated EOS-05 and also known as Gisat-1A, will lift off at 2:55 am aboard the Geosynchronous Satellite Launch Vehicle GSLV-F17, as reported by The Times of India.
The GSLV-F17 is the 19th flight of India's Geosynchronous Satellite Launch Vehicle, according to NewsBytes. The rocket will carry EOS-05 into a Sub-Geosynchronous Transfer Orbit, from where the satellite will move toward its intended orbit. Standing 51.7 meters tall and weighing 420.5 tons at liftoff, the three-stage launch vehicle uses the GSLV Mk II configuration with a four-meter-diameter ogive composite payload fairing.
The satellite and its capabilities
EOS-05 is an advanced Earth observation satellite that will operate from a geosynchronous orbit, allowing it to observe large areas of the Earth from a much higher altitude than conventional imaging satellites. According to The Times of India, the satellite will be positioned at an altitude of about 36,000 km, matching the speed of Earth's rotation so that it hovers over a fixed location. This enables continuous, real-time viewing of the same region without time gaps, unlike satellites in low Earth orbit (LEO) or sun-synchronous orbit, which may take days to revisit a particular location.
The satellite carries two multispectral imagers, one with a spatial resolution of 42 metres per pixel, as detailed by The Times of India. ISRO described EOS-05 as "state-of-the-art India's first-ever imaging satellite from geosynchronous orbit," according to the same report.
NewsBytes reported that the satellite's imaging capability could support monitoring of cyclones, floods, cloudbursts, and forest fires, among other natural events. The information could be useful for disaster management agencies, weather forecasters, agricultural planners, and security agencies, especially when quick updates are needed over large areas.
The Times of India noted that the satellite is meant for both military and civilian usage, providing what it described as continuous vigil on Indian borders and oversight of remote regions, strategic assets, and global conflict zones from space.
Mission context and significance
The EOS-05 launch comes after an earlier attempt to establish a similar capability failed. The GSLV-F10 mission carrying EOS-03 failed on August 12, 2021, due to an indigenous cryogenic upper stage problem, as reported by NewsBytes. The Times of India attributed the loss of the earlier satellite, Gisat-1, to a technical anomaly in the cryogenic upper stage of the GSLV-F10 rocket. EOS-05 is the successor to that lost mission, according to NewsBytes.
The current mission marks ISRO's return to the launchpad after a break of nearly eight months, as reported by The Times of India. NewsBytes noted that the mission comes after two consecutive PSLV (Polar Satellite Launch Vehicle) failures, though the GSLV and PSLV programs are separate and do not share engines or critical propulsion systems.
The EOS-05 launch is seen as a major test of the GSLV Mk II's reliability and its ability to place an Earth observation satellite into the required orbit, according to NewsBytes.