METSAT, launched by
PSLV-C4 this afternoon, is the first exclusive meteorological satellite built
by ISRO. So far, meteorological services had been combined with
telecommunication and television services in the INSAT system. METSAT will be a
precursor to the future INSAT system that will have separate satellites for
meteorology and telecommunication & broadcasting services. This will enable
larger capacity to be built into INSAT satellites, both in terms of
transponders and their radiated power, without the design constraints imposed
by meteorological instruments.
For meteorological observation, METSAT carries a
Very High Resolution Radiometer (VHRR) capable of imaging the Earth in the
visible, thermal infrared and water vapour bands. It also carries a Data Relay
Transponder (DRT) for collecting data from unattended meteorological platforms.
METSAT will relay the data sent by these platforms to the Meteorological Data
Utilisation Centre at New Delhi. Such platforms have been installed all over
At the time of its launch, METSAT weighed 1055 kg
including about 560 kg of propellant. The propellant carried by METSAT is
mainly required to raise the satellite from the Geosynchronous Transfer Orbit
to its final Geostationary orbit. METSAT will be located at 74 deg East
METSAT has been designed using a new spacecraft
bus employing lightweight structural elements like Carbon Fibre Reinforced
Plastic (CFRP). The satellite has a solar array generating 550 watts of power.
Solar Array Deployment
METSAT's solar array was automatically deployed
immediately after its injection into Geosynchronous Transfer Orbit (GTO) by
PSLV-C4. The successful deployment of the array as well as the general health
of the satellite were monitored by a ground station of the ISRO Telemetry,
Tracking and Command network (ISTRAC) located on the Indonesian island of Biak.
The Master Control Facility (MCF) at Hassan in Karnataka has taken control of
METSAT for all its post launch operations. Ground stations at Lake Cowichan
(Canada), Fucino (Italy) and Beijing (China) are supporting MCF in monitoring
the health of the satellite and its orbit raising operations.
In the coming days, METSAT's orbit will be raised
from its present elliptical Geosynchronous Transfer Orbit to the final
Geostationary Orbit by firing the satellite's Liquid Apogee Motor. The first
orbit raising operation is planned on September 13, 2002, by commanding from
MCF. The satellite will be commissioned into service after the completion of
orbit raising operations and positioning it in its designated orbital slot of
74 East longitude as well as the in-orbit testing of all the onboard systems.
The Vikram Sarabhai Space Centre,
Thiruvananthapuram, designed and developed PSLV. The inertial systems for the
vehicle were developed by the ISRO Inertial Systems Unit at Thiruvananthapuram.
The Liquid Propulsion Systems Centre also at Thiruvananthapuram developed the
Liquid propulsion stages for the second and fourth stages of PSLV as well as
the reaction control systems. Satish Dhawan Space Centre, SHAR processed solid
motors and carried out launch operations. ISTRAC provides Telemetry, Tracking
and Command support.
METSAT was developed by ISRO Satellite Centre,
Bangalore. The Meteorological payloads were developed by Space Applications
Centre, Ahmedabad. Master Control Facility at Hassan is responsible for all
post launch operations on the satellite. Several industries and academic
institutions were involved in today's PSLV-C4/METSAT Mission.
The successful launch of METSAT into
Geosynchronous Transfer Orbit has proved the versatility of PSLV to launch both
Polar and Geostationary satellites. Together with GSLV, it will enable India to
launch communication and meteorology and remote sensing satellites of different
weight classes. The exclusive meteorological satellite, METSAT, once
commissioned, is expected to vastly improve the meteorological services being
provided by INSAT systems.