T.S. Subramanian

Two Department of Ocean Development vessels are deployed on the recovery mission

We are yet to locate the failed engine, says ISRO ChairmanRecovery of failed engine will be an invaluable inputSearch was under way over an area of 500m by 500m

CHENNAI: A big exercise is under way to recover the debris of the GSLV-F02 (Geo-synchronous Satellite Launch Vehicle) from the Bay of Bengal off Sriharikota coast. Divers employed by the Department of Ocean Development (DoOD) have already recovered one of the strap-on motors of the GSLV-F02, which plunged into the sea on July 10. But this is not the strap-on engine, which malfunctioned and led to the failure of the flight from the Satish Dhawan Space Centre from Sriharikota, Andhra Pradesh.


Two DoOD vessels, Sagar Purvi and Sagar Kanya, are using ultrasonic equipment to "sound" the seabed and recover the debris.

G. Madhavan Nair, Chairman, Indian Space Research Organisation (ISRO), said one of the four strap-on motors recovered has been identified. "We are yet to locate the failed engine," he said on Monday from Bangalore.

"We are hopeful we will recover it in the course of this week. We have a certain hypothesis [on why the flight failed]. If we can recover the failed engine, it will be an added input. It will be definitely an invaluable input." On July 10, a couple of seconds after GSLV-F02 lifted off, one of the four strap-on booster engines strung around the core stage, failed. The pressure in that engine dropped to zero and so the vehicle did not build up enough thrust. The rocket veered off its

flight path. The angle of attack, that is the cumulative forces acting on the vehicle, was 10 degrees. The vehicle was designed to withstand an angle of attack of four degrees.

When the rocket hurtled off its trajectory, Range Safety Officer V. Krishnamurthy pressed the `destruct' button, triggering the explosives wired to the rocket.


It was detonated to prevent it from falling on the ground and injuring people. The debris fell into the Bay of Bengal, whose waters surround Sriharikota.

Mr. Nair said that when ISRO asked the DoOD for help in recovering the engines, the DoOD led by its Secretary P.S. Goel was "very cooperative." .

"In [the] normal course, it would have been a difficult exercise. But here, the waters [where the rocket parts fell] are not very deep," Mr. Nair said. The search was under way over an area of 500 metres by 500 metres.

Video pictures

Another top ISRO official said though it was an extensive area "the video pictures of the flight showed the flash points" and "we used the triangulation a little bit to approximately locate the area," where the rocket parts plunged into the sea. This was about six to seven km from the island's shore.

The depth there was not more than 25 metres but still it was difficult for the divers to go in. "If we can lay our hands on the failed engine," it would provide an insight into the reasons behind the failure of the mission, he said.

"It is not that we cannot do our job [of specifying the reason for the failure] without the failed engine but it will always be helpful if we can recover it. Each strap-on engine has identification marks," he said. If the parts had fallen into the deep sea, this exercise would not have been thought of.

In the meantime, members of the Failure Analysis Committee set up to find out the cause of the mission failure were "on their job and going through the data" available, ISRO sources said.

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