Thaindian News

Chennai, Dec 24 (IANS) The 30-hour countdown for the launch of advanced communication satellite GSAT-5P started 10.04 Friday morning at the Sriharikota rocket launch centre, about 80 km from Chennai, an official of the Indian Space Research Organisation (ISRO) said.The Rs.125 crore (Rs.1.25 billion) GSAT-5P satellite weighing 2,130 kg will serve the needs of the telecommunication, televison and weather sectors. It will eventually retire the INSAT-2E satellite that was sent up in 1999.

If all goes well, the satellite will be blasted off Saturday afternoon.

The GSAT-5P satellite with a life span of over 13 years has 36 transponders - automatic receivers and transmitters for communication and broadcast of signals. Successful launch of GSAT-5P will take the agency’s transponder capacity to about 235 from the 200 currently in the orbit.

“The geosynchronous satellite launch vehicle (GSLV) carrying GSAT-5P will blast off from the second launch pad at Satish Dhawan Space Centre Saturday evening at 4.04 p.m.,” S.Satish, an ISRO director, told IANS.

The GSLV rocket is 51 metres tall, weighs 418 tonnes and costs around Rs.175 crore (Rs.1.75 billion).

ISRO officials told IANS that the filling of liquid and cryogenic fuel will be carried out during the countdown till 30 minutes before the actual lift-off.

The GSLV rocket has three stages. The first stage is fired by solid fuel. The four strap-on motors give additional thrust during the lift-off and the initial phase of the rocket’s flight.

The second stage is fired by liquid fuel. The third stage, more complex than the others, involves the cryogenic engine powered by liquid hydrogen as fuel and liquid oxygen as oxidiser.

The launch was originally scheduled last Monday, but was aborted Sunday a leak was detected in one of the valves of the Russian-made cryogenic engine. Later, tests ensured the stability of the valve and the ISRO gave the go-ahead for Saturday launch.

The ISRO currently has the following communication satellites in service - INSAT 2E, INSAT 3A, INSAT 3B, INSAT 3C, INSAT 3E, INSAT 4A, INSAT 4CR and INSAT 4B working at 50 percent capability, Satish said.

ISRO launched two major satellites in 2010 - communication satellite GSAT-4 and remote sensing satellite Cartosat-2. GSAT-4 launch failed after the rocket crashed into the Bay of Bengal while Cartosat-2 was placed successfully in the orbit.