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INSAT 3A
Mission type	Communications; Weather
Operator	INSAT
COSPAR ID	2003-013A
SATCAT no.	27714
Website	INSAT 3A
Spacecraft properties
Manufacturer	ISRO
Launch mass	2,950 kilograms (6,500 lb)
Dimensions	2.8 x 1.7 x 2.0 metres
Power	3.1 kilowatts
Start of mission
Launch date	9 April 2003, 22:52 UTC
Rocket	Ariane 5G V160
Launch site	Kourou ELA-3
Contractor	Arianespace
Orbital parameters
Reference system	Geocentric
Regime	Geostationary
Longitude	93.5° East (0°00′N 93°30′E / 0°N +93.5°E)
Inclination	74 degrees
Period	12 years

INSAT-3A, a multipurpose satellite built by ISRO was launched by Ariane in April 2003. It is located at 93.5 degree East longitude. It is third satellite in INSAT-3 series after INSAT-3B & INSAT-3C. Built at a cost of $53 mn, it provides communication, weather, and search and rescue services.

Launch

INSAT 3A was launched by Ariane-5 launch vehicle of Arianespace on April 9, 2003, at 22.52 UTC from Kourou, French Guiana.^[1] It was placed into a Geosynchronous Transfer Orbit (GTO), 30 minutes after the lift-off in 3-axis stabilized mode, with a perigee (nearest point to earth) of 859 km and an apogee (farthest point to earth) of 36,055 km and an inclination of 1.99 degrees with respect to the equator.^[2] Its co-passenger on its launch was GALAXI-XII of PanAmSat. Its Master Control Facility (MCF) is located at Hassan, Karnataka (India). It is 3-axis body stabilised in orbit using momentum and reaction wheels, solar flaps, magnetic torquers and eight 10 N and eight 22 N reaction control thrusters. Its propulsion system consists of 440 N Liquid Apogee Motor MON-3 (Mixed Oxides of Nitrogen) and MMH (MonoMethylHydrazine) for orbit raising.

The satellite raised its orbit to GEO and arrived in the 93.5 degree East longitude orbital location.^[3] It joined INSAT-3B and INSAT-3C which were already in orbit operating from a similar orbital location.^[4]

Payload

Communication payload

The INSAT-3A communications payload consists of:^[5]

12 Normal C-band transponders (9 channels provide expanded coverage from Middle East to South East Asia with an EIRP of 38 dBW, 3 channels provide India coverage with an EIRP of 36 dBW and 6 Extended C-band transponders provide India coverage with an EIRP of 36 dBW).
6 upper extended C-band transponders having India beam coverage providing an EoC-EIRP of 37 dBW.
6 Ku-band transponders provide India coverage with EIRP of 48 dBW.

Meteorological payload

The INSAT-3A meteorological payload consists of^[5]

A Very High Resolution Radiometer (VHRR) with imaging capacity in the visible (0.55-0.75 μm), thermal infrared (10.5-12.5 μm) and Water Vapour (5.7-7.1 μm) channels, provide 2x2 km, 8x8 km and 8x8 km ground resolutions respectively.
A CCD camera provides 1x1 km ground resolution, in the visible (0.63-0.69 μm), near infrared (0.77-0.86 μm) and shortwave infrared (1.55-1.70 μm) bands.
A Data Relay Transponder (DRT) having global receive coverage with a 400 MHz uplink and 4500 MHz downlink for relay of meteorological, hydrological and oceanographic data from unattended land and ocean-based automatic data collection-cum-transmission platforms.
A Satellite Aided Search and Rescue (SAS&R) SARP payload having global receive coverage with 406 MHz uplink and 4500 MHz downlink with India coverage, for relay of signals from distress beacons in sea, air or land. See also Cospas-Sarsat.^[6]