The Hindu : 'Next GSLV version to carry heavier satellite'

Online edition of India's National Newspaper
Saturday, May 10, 2003

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'Next GSLV version to carry heavier satellite'

By R.K. Radhakrishnan

CHENNAI MAY 9. The next version of the Geo-synchronous Satellite Launch Vehicle, GSLV Mark 2, will be able to carry a maximum satellite weight of 2,250 kg, according to the Indian Space Research Organisation Chairman, K. Kasturirangan.

"We are planning to go up to 2,250 kg once we develop that," he said at the Satish Dhawan Space Centre, Sriharikota, on Thursday.

The ISRO Chairman highlighted the burgeoning demand for transponder capacity in the country and said that 2,000 kg satellites could be built and launched to bridge the demand. This class of satellite can have up to 24 transponders with "low power" or 12 transponders with high power. He said the transponders on this class of satellites could be used to augment the transponder demand, even as the heavier satellites were being launched from time to time. "We could ensure that there is a right mix between the two."

The first experimental flight of the GSLV-D1, in April 2001, carried a 1,530 kg satellite. The next one, launched on Thursday, the GSLV-D2 carried a satellite weighing almost 30 per cent more — 1,800 kg. This is now sought to be increased to over 2,000 kg with a series of improvements to the launch vehicle and the use of lighter, composite materials.

The first experimental flight, though a success, had to contend with an underperforming cryogenic stage, the most important of the three stages that compose the rocket. This stage was procured from Russia before the Missile Technology Control Regime decreed that dual use technology should not be transferred to third countries. India was given seven cryogenic engines of which two have now been used.

To ensure that the problem in the first flight did not recur, ISRO and Russian engineers have worked in close liaison to figure out the mistakes. While the Russians think that the handling of the third stage fuel was to be blamed for the failure, ISRO was insistent that the entire data should be analysed to come to a conclusion. "Last time, there was a problem in the total management of the cryogenic fluid in the upper stage. We went through the telemetry data. This has been well characterised through a series of tests conducted in laboratories in Russia as well as here. Based on this, we have fine-tuned the performance of the upper stage," said Madhavan Nair, Director, Vikram Sarabhai Space Centre, Thiruvananthapuram.

Asked about the demand for GSLV launches, Dr. Kasturirangan said the GSLV offered an opportunity for two tonne class of satellites. "This particular kind of launch can be very cost competitive when you talk of launching a two tonne class of satellite. But then there have to be customers who can build two tonne class of satellites. There are a few. We are discussing with them. Probably they will use this since this is a niche vehicle for a 2,000 kg satellite," he said.

On the development of an indigenous cryogenic engine, he said that ISRO was now embarking on collecting a larger database after completing a series of performance tests. "The third part is to convert the engine into a stage. Currently that work is progressing. In the next few months we will start testing the stages and that will be the kind of qualification that will lead us to use this stage for our GSLV."

The third developmental flight will carry the Indian cryogenic stage. "In the next two years we want to complete the development of the stage."

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