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)
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 |
