Indian space agency's ex-chief to help analyse rocket crash

Indian space agency's ex-chief to help analyse rocket crash

“I will be guiding the various teams that are studying the flight data of the GSLV (geosynchronous satellite launch vehicle) rocket to arrive at the cause of failure,” Nair told IANS.

On Christmas day, a GSLV rocket (weight 418 tonnes, cost Rs.175 crore or $38 million) carrying advanced communication satellite GSAT-5P (weight 2,310 kg, cost Rs.150 crore) veered off its flight path and began disintegrating within one minute after lift-off from Sriharikota in Andhra Pradesh.

“On the day of the failure it was announced the connectors relaying the command led to the rocket’s failure. We have revisited and have confirmed that the connectors located between the cryogenic engine and the lower stage (engine) snapped. We have to find why the snapping happened,” Nair said.

“As per the data there are no indications of any control command from the onboard computers to the rocket engines,” he said.

He said simulated experiments will have to be carried out to find out why the connectors got disconnected from the rocket.

“Whether vibrations or external forces led to the snapping of connectors has to be found out. We will have to conduct simulation experiments to find that out,” Nair said.

To a query as to why the ISRO was taking a long time to come out with a preliminary report, he said: “The preliminary data runs into more than 100 pages even though the flight is of around 50 seconds.”

On a suggestion of using a dummy payload instead of a real satellite costing around Rs.150 crore till the ISRO stabilises its heavier rocket, Nair said: “The efforts required for both are more or less the same. However, if the satellite is slung into the orbit then it throws up an opportunity to earn higher revenue.”

According to an ISRO official, the GSLV rocket’s four strap-on motors were powered by liquid fuel whereas the other rocket, polar satellite launch vehicle (PSLV), used  strap-on motors powered by solid fuel.

“Liquid fuel powered engine is more complicated than solid fuel powered one as the former will have more components like valves. The reason for using liquid fuel is that it provides around 20 percent higher thrust for the rocket to go up. The Russian rockets use liquid fuel in engines,” said the official, who preferred anonymity.

He said the first 50 km are the most critical in a rocket's flight as during this phase it faces intense external pressure.

“Hence, the first-stage engine’s role is to carry the rocket upwards with least complicated systems,” he said.

According to him, it takes time for any space agency to master its technology.

“Even Russia lost its rocket and satellites early this month,” he said.

This year India has lost two GSLV rockets with their satellites and the total loss has been around Rs.660 crore. In 2006, another GSLV rocket exploded mid-air with its satellite resulting in a loss of around Rs.260 crore.

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