Indigenous cryogenic technology to power latest ISRO satellite

Apart from the first time use of ‘made in India’ cryogenic technology,the launch on April 15 will also involve one of the heaviest satellites ever put in space by Indian satellite launch vehicles.

The successful launch of the GSAT-4 will elevate India’s growing status as a space faring nation putting it in the league of a handful of nations that can launch satellites weighing above two tonnes in the geo synchronous orbit.

Past Indian satellite launches involving the Geo Synchronous Satellite Launch Vehicles have relied on cryogenic stages provided by Russia as part of an agreement for seven cryogenic stages.

“We are talking of strategic technology that only five countries in the world have — US,Russia,Japan,France and China. We are talking of a technology which one country stopped us from getting. This is the kind of geo-political ramifications of this technology,” chairman of ISRO Dr K Radhakrishnan said here on Wednesday.

In 1992,India had first ventured on the path of obtaining cryogenic technology with a two pronged strategy — purchase of cryogenic engines from Russia and acquisition of technology. Following the 1998 nuclear tests the technology was denied as US imposed sanctions on dual use technologies.

“This is like the ultimate in rocket technology. It gives unprecedented power in the final stage of a rocket’s flight,” says P S Veeraraghavan,director of ISRO’s Vikram Sarabhai Space Centre.

The cryogenic technology was denied in the late 1990s to India under the impression that it would be used in parallel for the missile development programme,say ISRO scientists.

“We tried to tell them (the US) that cryogenic technology is not suited for missile programmes because it is cumbersome. They did not want us to have the technology. It is,however,true the rocket can be used for defence purposes,but ISRO’s programmes have always been for peaceful ends and there is a clear demarcation,” said an ISRO scientist.

The cryogenic stage on the GSLV D3 is the third stage and uses liquid hydrogen as fuel and liquid oxygen as an oxidiser.

“Cryogenic stage is a rocket stage that is much more efficient and provides more thrust for every kg of propellant it burns compared to solid and earth-storable liquid propellant stages. The specific impulse achievable with cryo fluids is 450 seconds compared to 300 sec for other fuels,” ISRO officials said.

The satellite being launched on the GSLV D3 will be the 19th geo stationary satellite from the ISRO stable and the fourth in the GSAT series.