Chennai: The 25-hour countdown for the launch of RISAT-2B, a radar imaging earth observation satellite using PSLV-C46, began at 4.30 am today in the spaceport of Sriharikota.
Indian Space Research Organisation (ISRO) sources said the launch would take place from the First Launch Pad at 5.30 am Wednesday. About 15 minutes after lift off, the 300 kg RISAT-2B will be placed into an orbit of 555 km at an inclination of 37 deg to the equator.
Earlier, the Mission Readiness Review Committee met at SDSC and after the Launch Authorisation Board gave its clearance, the countdown commenced, during which propellant filling operations would be taken up ut in the four-stage 44.4 metre tall vehicle.
RISAT-2B is the fourth flight unit of the RISAT programme and it would be used for reconnaissance, strategic surveillance and disaster management. It uses an active SAR (Synthetic Aperture Radar) imager to provide continuity of service for RISAT-2.
The launch of RISAT-2B will also mark resumption of a vital ring of Indian all-seeing radar imaging satellites after seven years. The sources said that when it was cloudy or dark, ‘regular’ remote-sensing or optical imaging satellites, which work like a light-dependent camera, could not perceive hidden or surreptitious objects on the ground.