Cryogenic engine remains our priority 8212; ISRO

He said the country was forced to suddenly start developing the cryogenic technology completely on its own as the Russian space agency Glavkosmos went back on its word, under pressure from the United States, to provide the technology along with the contract to supply the cryogenic engine for the upper stage of the GSLV.

Stating that every space event is fraught with tension, he listed the challenges which included the absence of Dr Vikram Sarabhai, who planned and implemented the early space programme, designing of Aryabhatta satellite, making Bhaskara beam television pictures, developing world class remote sensing satellites and establishment of INSAT system.

Dr Kasturirangan said developing Aryabhatta, the very first Indian satellite, from scratch with absolutely no no infrastructure was one of the toughest things that Indian space scientists have ever done. New scientists were hired, trained, facilities built up, all in a very short time and Aryabhatta was launched in April 1975 on the inter-cosmos rocket of the erstwhile USSR.

Bhaskara-L, an experimental remote sensing satellite, was launched in June 1979 with a television camera on board. However, a high voltage terminal employed in the instrument quot;arcedquot; due to a suspected outgassing evaporation of certain compounds in high vacuum. The camera was in a quite bad shape and looked unusable, but the scientists decided to wait for eight to nine months for the gases to dissipate. The camera finally functioned in 1980. quot;The challenge here was in taking decisions about the environment, inside a satellite in orbit 350 km above earthquot;, he said.

Another major challenge, according to the Indian Space Department secretary was overcoming the failures of the launch of two Augmented Satellite Launch Vehicle ASLV. immediately after the development of the first launch vehicle quot;SLV 3quot; successfully, ISRO added two first stage motor strapons and augmented to make it the ASLV. However, the mission failed when the first stage did not catch on after the strap on stage burnt out. No data was received to evaluate performance. The second flight, 15 months later, also failed, but gave some feedback about flaws in the launch vehicle design.

This enabled space scientists to correct the design and launch both subsequent ASLVs successfully as well as the next generation Polar Satellite Launch Vehicle PSLV.

PSLV now is a successful launch vehicle having placed three satellites in orbit in its last launch in May last year. But operationalising it was a big challenge, according to Dr Kasturirangan. It was a 293 tonne, 44 M High vehicle with solid and liquid propulsion stages and employed closed loop guidance. Besides, its trajectory design involved quot;AYAWquot; manoeuvre to avoid land masses in the flight path.

Developing world class remote sensing satellites was yet another major challenge. Though the IRS satellites were now acknowledged as among the best in the world, but getting there was an uphill task as was the development of a strong user base for remote sensing applications that now cover several areas.