71-hour Countdown proceeding smoothly

CHENNAI: The 71-hour
countdown for the launch of
Polar Satellite Launch Vehicle
(PSLV), which would
put the 1,858 kg India’s
fi rst radar imaging satellite
RISAT-1in the orbit, was
progressing smoothly.
ISRO sources said the
countdown which began at
0647 hrs on Monday morning
was progressing without
any hitch at the Satish Dhawan
Space Centre at Sriharikota,
about 100 km from
here. The extended version
of ISRO’s workhorse launch
vehicle PSLV-XL, carrying
RISAT-1, would lift from
the fi rst launch Pad at 0547
hrs on April 26.
PSLV-C19 will inject
RISAT-1 satellite into an orbit
of 480 km altitude at an
inclination of 97.552 deg.
The satellite will be put in its
fi nal orbital confi guration at
536 km altitude using thrusters
onboard the satellite.
Having a life span of fi ve
years, RISAT-1 is basically
a remote-sensing satellite.
It would be ISRO’s fi rst radar
imaging satellite, which
could take pictures of the
earth In all conditions --
rain, sun, fog and cyclones
-- and through the clouds
using synthetic aperture radars.
This is also the heaviest
remote sensing satellite
built by ISRO.
It would be another fi rst
for PSLV, the ISRO’s workhorse
satellite launch vehicle,
as it would be placing
the heaviest satellite in the
polar orbit.
Since it is the heaviest
satellite, ISRO would be using
the XL (extended large)
version of PSLV (PSLVXL),
which was earlier used
for the launch of Chandrayaan-
1 mission in October
2008 and again for the
launch of GSAT-12 in July
last year.
PSLV-XL uses six additional
powerful strap-on
motors, each containing
12 tonnes of solid propellants,
when compared to
the standard PSLV version
which uses nine tonnes of
solid propellants in each of
the six strap-on.
Pictures taken from
RISAT-1 would be used to
estimate the crop yield, especially
to monitor paddy
crop, assess its acreage and
predict its health during the
kharif season, when the sky
was covered with clouds.
The images could also be
used for disaster management
during cyclones and
fl oods, besides assessing the
extent of inundation caused.