India's first indigenously built all-weather Radar Imaging Satellite, RISAT-1, with applications ranging from agriculture to natural disaster management, is now in polar orbit after its carrier, the PSLV-C19, was launched with clinical precision from the Sriharikota spaceport of the Indian Space Research Organisation (ISRO) on Thursday.

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RISAT-1, weighing 1,858 kg and the heaviest satellite launched yet by the PSLV, is a state-of-the-art Active Microwave Remote Sensing Satellite carrying a Synthetic Aperture Radar (SAR) that will operate in the C-band.

In simpler terms, the RISAT-1 can beam back imaging of the earth surface features at day and night and under all imagined weather conditions. SAR, which gives the RISAT-1 its magical roving eyes, also makes it superior to the generation of optical remote sensing satellites in clearer imaging at all times and under any condition.

Terming the PSLV-C19 launch a “grand success,” ISRO Chairman K. Radhakrishnan said the RISAT-1 was precisely injected into an orbit in an altitudinal range of about 480 km. In the next three days, it would be raised to a 536-km polar orbit. After the satellite was placed in orbit, solar panels and SAR antenna were successfully deployed. This antenna would shortly be pointed at the earth, and by May 1, imaging operations were expected to be launched, he said.

According to ISRO scientists, once its on-board propulsion system raised the orbital altitude to 536 km, the satellite will begin its daily routine of 14 orbits with a repetitive cycle of 25 days. During its mission life of five years, the RISAT-1 will use its active microwave remote sensing capability for cloud penetration and day-night imaging of the earth surface and provide critical data inputs for a range of agricultural and soil moisture studies and forestry applications. Among the many tasks the RISAT-1 can perform are paddy monitoring in kharif season, crop estimation and mapping of forestry biomass, besides providing the big picture on natural disasters such as flood and cyclone.

In the early hours of Thursday, the mission command centre at the ISRO's Satish Dhawan Space Centre here went through the customarily tense countdown leading to the lift-off. At precisely 5.47 a.m., the launch vehicle's core stage and a set of six strap-on motors ignited within seconds to signal the successful lift-off of the PSLV-C19, with the satellite firmly docked in its metal frames.

Jubilant scenes erupted at the mission command centre once the PSLV-C19 executed with programmed precision each of the four stages of ignition and separation in a flight of 18 minutes, and in one final push injected the RISAT-1 into orbit with an altitude of about 480 km.

Prof. Yashpal and Prof. U.R. Rao, two of the doyens of India's space programme, were present to partake of the celebrations of what they described as a landmark event.

The approved cost of the mission was Rs. 488 crore — the assembling of the satellite involved Rs. 378 crore and the rocket Rs.110 crore.

The PSLV C-19 is the 21st flight in the PSLV series of satellite launches, the 20th consecutive successful launch and the third to involve the high-end version (PSLV-XL) equipped with six extended strap-on motors, each carrying 12 tonnes of solid propellant. The two earlier flights of the PSLV-XL were used to launch Chandrayaan-1 and the GSAT-12 communication satellite.