ISRO set to launch GSLV-D3

"Preparations are going on. The final reviews are also taking place. It could be any day from April 15 (at around 16.30 hours), which is the first available opportunity", he said.

GSLV-D3 would carry on board GSAT-4 experimental satellite in which ISRO is also testing some new things.

He said the indigenous development of complex cryogenic rocket technology after years of effort is a reply to technology denial regimes and termed the endeavour "marvellous".
"Significance in terms of (cryogenic) technology development has been a marvellous thing", he said.

"In 1992, we wanted to get this technology from Russia, and the Americans put a sanction on Russia not to transfer this technology and India took a bold decision to develop it. So, we have done it", he said.

"This is a flight-testing of that (indigenous cryogenic) stage," Radhakrishnan said.
Indigenously developed Cryogenic Upper Stage (CUS) being used for the first time in GSLV-D3 is fully qualified having undergone the full flight duration test of 800 seconds successfully. The indigenous CUS would be used in place of Russian cryogenic stage employed so far in GSLV.

"The development of cryogenic engines involves mastering several complex disciplines such as materials technology, operating rotary pumps and turbines that run at 42,000 rpm at cryogenic temperatures. The development of cryogenic technology in the country has given the coveted status of total self-reliance in launch vehicle technology", he said.

ISRO conducted previous GSLV flights with the help of readymade cryogenic engines procured from Russia earlier.

"GSAT-4 is the only payload (to be carried by GSLV-D3). But GSAT-4 contains several payloads. We are getting into Ka-band transponder system there, and we are also having a small payload for the satellite navigation for augmenting the GPS system that is GAGAN (GPS Aided GEO Augmented Navigation)," Radhakrishnan said.

ISRO is also trying electric propulsion system for the first time. "Instead of using liquid fuel for station-keeping, here you are using electric propulsions", he said, noting the move would enable the agency to extend the life of satellites by a couple of years.
"This is a new technology. First time, we are trying it," he said.