INSAT–4B Spacecraft is the second in the INSAT 4
series of spacecrafts and is configured with exclusive communication payloads
to provide services in Ku and C frequency bands. This is co-located with
INSAT–3A at 93.5 o E longitude.
Mission
Communication
Weight
3025 Kg (at Lift – off)
Onboard Power
5859 W
Stabilization
It uses 3 earth sensors, 2 digital sun sensors, 8 coarse
analog sun sensors, 3 solar panel sun sensors and one sensor processing
electronics. The wheels and wheel drive electronics were imported with
indigenous wheel interface module to interface the wheel drive electronics and
AOCE.
Propulsion
The propulsion system is employing 16 thrusters, 4 each
located on east, west and AY sides and 2 each on north and south sides. There
is one 440 N liquid apogee motor (using Mono Methyl Hydrazine (MMH) as fuel and
oxides of Nitrogen ( MON3 as oxidizer) and three presurant tanks mounted on the
LAM deck.
Payload
12 Ku band high power transponders covering
Indian main land using 140W radiatively cooled TWTAs.
12 C band high power transponders with extended coverage, covering
southeast and northwest region apart from Indian main land using 63 W TWTAs
