The third stage used 7.6 tonne of HTPB-based solid propellant and was capable of producing a maximum thrust of 246 kN. Its motor case was made of polyaramide fibre. The fourth and the terminal stage of PSLV had a twin engine configuration using liquid propellant. With a propellant loading of 2.5 tonne (Mono Methyl Hydrazine and Mixed Oxides of Nitrogen), each of those engines had the capability to generate a maximum thrust of 7.3 kN.
The 3.2 m diameter metallic bulbous payload fairing of PSLV was of isogrid construction and its function was to protect the spacecraft during the atmospheric regime of flight. PSLV employed a large number of stage auxiliary systems for stage separation, payload fairing separation and jettisoning, etc.
PSLV-C5 control system consisted of: a) First stage: Secondary Injection Thrust Vector Control (SITVC) for pitch and yaw, reaction control thrusters for roll
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| RESOURCESAT-1 sitting on top of PSLV-C5 fourth stage |
b) Second stage: Engine gimbal for pitch and yaw and, hot gas reaction control motor for roll control c) Third stage: flex nozzle for pitch and yaw and PS-4 RCS for roll control and d) Fourth stage: Engine gimbal for pitch, yaw, and roll and, on-off RCS for control during the coast phase.
The inertial navigation system in the equipment bay, which was located on top of the fourth stage, guided the vehicle from lift-off to spacecraft injection into orbit. The vehicle was provided with instrumentation to monitor the vehicle performance during the flight. S-band PCM telemetry and C-band transponders catered to this requirement. The tracking system provided real-time information for flight safety and for preliminary orbit determination once the satellite was injected into orbit.
With seven successive successful launches, PSLV has proved itself as a reliable vehicle for launching Indian remote sensing satellites. Besides, it has been used for launching a geosynchronous satellite, KALPANA-1. ISRO has proposed to use PSLV for India's first unmanned mission to moon, Chandrayaan-1. The President and the Prime Minister watched the launch of RESOURCESAT-1 by PSLV-C5 live on TV at Delhi. Immediately after the satellite was placed in orbit, the President and the Prime Minister congratulated ISRO Scientists and all others involved in the mission. They conveyed their messages over telephone to Mr G Madhavan Nair, Chairman, ISRO. Mr Satyabrata Mookherjee, Minister of State (Space), who was present at SHAR to witness the launch, stated that with that successful launch, the seventh in a row, the reliability of PSLV as a workhorse launch vehicle for launching our remote sensing satellites was unequivocally demonstrated.
