Metsat is an exclusive meteorological satellite of ISRO in geo-synchronous orbit. This satellite is developed out of a small I-1000 bus made of carbon fibre re-enforced plastic light weight structure, a uni power bus employing an 18AH Ni-Cd battery and a single GaAs/Ge solar panel generating 640 watts of power. Metsat uses a 3-axis stabilized momentum biased attitude control system with suitable linearly controlled magnetic torquers for solar radiation pressure compensation. A unified propulsion system of bi-propellant apogee motor of 440 Newtons and the reaction control engines of 22 Newtons has been selected for efficient and versatile mission management.
Metsat carries on-board a Very High ResolutionRadiometer (VHRR) and a Data Relay Transponder (DRT) for weather data transmission. VHRR provides earth imageries in visible band with a resolution of2 km, in thermal infrared and water vapor bands with 8 km. DRT collects weather data from un-attended data collection platforms located throughout India and transmits the same to centrally located Meteorological Data Utilisation Centre. The satellite dry mass is about 495 kg. Metsat was launched on- board upgraded and modified satellite launch vehicle (PSLV) with a lift–off mass of 1060 kgs in September 2002. After successful launch and early orbit operations and in orbit characterization of the Payload, the satellite has been commissioned for routine usage of weather data and imageries.