New Delhi, Nov. 3: From the turbid monsoon waters of the Bay of Bengal, divers have retrieved wreckage of the Geosynchronous Satellite Launch Vehicle that had plunged into the sea in July, but its rogue engine may be lost forever.

In a four-month campaign, ocean scientists retrieved three strap-on booster rockets attached to the first stage of the GSLV but could pick up only the nose cone and electronics of the fourth strap-on — the part that had failed, causing the launch vehicle to crash into the sea.

“This is only the second attempt in the world to recover debris of a commercial launch vehicle,” Kapil Sibal, minister of science and technology and earth sciences, said today.

In 1996, the European Space Agency had recovered the wreckage of the failed maiden test flight of the Ariane 5 launch vehicle that had crashed into a mangrove swamp and savannah.

The GSLV had deviated from its intended path about 55 seconds into its flight on July 10, resulting in the vehicle breaking up and falling into the bay.

A failure analysis committee set up by the Indian Space Research Organisation (Isro) had in September pinpointed the cause of the malfunction — a single flaw in a fuel flow control device, embedded deep inside S4, the fourth strap-on booster.

At the request of the Isro, ocean scientists used ships and sonar to scan the seabed 6 to 7 km from the coast, picking up hundreds of “targets” — suspected pieces of wreckage lying in the bay that is choppy, turbid and dark at the bottom during the monsoon.

Between July and September, divers recovered the engines of the three strap-on boosters, S3, S2, and S1, that had functioned normally. Another search in October yielded the nose cone (picture above), electronics and twisted and broken metallic pieces of the S4 but not the engine.

Isro sources said without the recovery of the S4 engine, the other hardware that has been recovered is unlikely to add fresh data to the findings of the committee, which had analysed flight details and used ground simulations to determine what had gone wrong.