Indian satellite launch vehicle now taller, heavier

CHENNAI - India’s satellite launch vehicle, which is scheduled to blast off Monday with an advanced communication satellite to retire one sent up in 1999 and ensure continuity of telecom, TV and weather services, is now taller by two metres and heavier by four tonnes as compared to its standard configuration.

The Indian Space Research Organisation’s standard configuration for the geosynchronous satellite launch vehicle (GSLV) rocket is a height of 49 metres and 414 tonnes in weight at lift-off.

The rocket that would lift off Monday with the satellite, officially called GSAT-5P, stands 51 metres tall and weighs 418 tonnes.

P.S. Veeraraghavan, director of the Vikram Sarabhai Space Centre, told IANS: “This time the fuel quantity for the cryogenic engine has increased and its thrust power has also gone up. The rocket will be carrying a heavier satellite (GSAT-5P) weighing 2,310 kg.”

The Russian made cryogenic engine will be powered with 15.2 tonnes of fuel (liquid hydrogen as fuel and liquid oxygen as oxidizer), an increase of around three tonnes, and the engine’s length has also increased.

The rocket has a bigger heat shield - four-metres in diameter and made of fibre reinforced plastic (FRP) - as compared to the standard configuration of 3.4-metre diameter made of aluminium alloy metal.

With the changes in rocket’s configuration, necessary calibrations have been carried out in the rocket’s navigational systems, control dynamics and aerodynamics so that the flight is smooth and the mission is successful, a source associated with ISRO told IANS.

Over the years, the carrying capacity of the GSLV has also increased — from 1,530 kg in 2001 for GSAT-1 to 2,220 kg for GSAT-4 in April 2010.

The latest has a payload of 2,310 kg with 36 transponders — an automatic receiver and transmitter of communication or broadcast signals. Successful launch of the satellite will take the agency’s transponder capacity to around 235 from 200 in orbit now.