PSLV-C19 SUCCESSFULLY LAUNCHES RISAT-1

The PSLV-C19, the newest in the series of polar satellite launch vehicles of the Indian Space Research Organisation (ISRO), burst off the launch-pads of Sriharikota in the wee hours of April 26 on its space mission of placing indigenously developed Radar Imaging Satellite the RISAT-1 in a polar circular orbit.

After a customarily tense countdown at the ISRO's Satish Dhawan Space Centre in Sriharikota, at precisely 5.47 a.m., the launch vehicle’s core stage igniters and set of six strap-on motors ignited within seconds of each to signal the successful lift-off of the PSLV-C19 with the RISAT -1 firmly docked inside its metal frames. 

The RISAT-1 with a payload of 1858 kg, the heaviest satellite being launched yet by the PSLV, is a state-of-the-art Active Microwave Remote Sensing Satellite carrying a Synthetic Aperture Radar (SAR) payload that will operate in the C-band. In simpler terms, the RISAT-1 can beam back imaging of the earth surface features during day and night and under all imagined weather conditions. The SAR which gives the RISAT-1 its magic lens also makes it superior to the generation of optical remote sensing satellites in terms of clearer imaging at all times and under any condition.

Once the PSLV-C19 successfully completed each of the four stages of its flight in a span of 18 minutes and reported normal parameters, congratulatory scenes broke out at the Mission Directorate at Sriharikota. 

According to ISRO scientists, once the satellite onboard propulsion system will raise the orbital altitude to 536 km with orbital inclination of approximately 97 degrees to place the RISAT-1 into a polar sun-synchronous orbit, the satellite will begin its daily routine of 14 orbits with a of 25 days. During its mission life of five years, 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 applications.

The satellite’s applications will range across agriculture — paddy monitoring in the kharif season — and management of natural disasters like flood and cyclone and could greatly assist food security planning in India.

The Polar Satellite Launch Vehicle, in its 21st flight (PSLV-C19), launches India’s first Radar Imaging Satellite – RISAT-1 into a Polar Circular Orbit with an altitude of 480 km (+ 40.5 km) and orbital inclination of 97.552 (+ 0.2). RISAT-1 weighing 1858 kg is the heaviest satellite being launched by PSLV.

This is the third flight of the high end version (PSLV-XL) with six extended strap-on motors, each carrying 12 tonnes of solid propellant. (The two earlier flights of PSLV-XL were used to launch Chandrayaan-1 and GSAT-12 Communication Satellite) 

 RISAT-1

Radar Satellite-1 (RISAT-1) is a state of the art Microwave Remote Sensing Satellite carrying a Synthetic Aperture Reader (SAR) Payload operating in C-band (5.35 GHz), which enables imaging of the surface features during both day and night under all weather conditions. 

Lift-off Mass	1858 kg
Orbit	Circular Polar Sun Synchronous
Orbit Altitude	536 km
Orbit Inclination	97.552o
Orbit Period	95.49 min
Number of Orbits per day	14
Local Time of Equator Crossing	6:00 am / 6:00 pm
Power	Solar Array generating 2200 W and one 70 AH Ni-H2 battery
Repetivity	25 days
Attitude and Orbit Control	3-axis body stabilised using Reaction Wheels, Magnetic Torquers and Hydrazine Thrusters
Nominal Mission Life	5 years
Launch date	April 26, 2012
Launch site	SDSC SHAR Centre, Sriharikota, India
Launch vehicle	PSLV- C19