A malfunctioning turbo pump in the indigenous cryogenic engine has been identified as the rogue component which sent the Geosynchronous Satellite Launch Vehicle (GSLV-D3) into the Bay of Bengal soon after lift off on April 15, 2010.
“The Fuel Booster Turbo Pump ought to have achieved a maximum speed of 42,000 rpm, but it reached 34, 800 rpm and stopped. It is quite clear that the basic problem was that the pump failed in seconds after the cryogenic upper stage was switched on, but it is not clear why it failed,” Prof. Roddam Narasimha, a member of the Indian Space Commission and one of the experts who reviewed data of the unsuccessful flight, told this newspaper.
“It could either be because of a snag in one of the components like rotors or shaft, opening of the casing over the turbine, or contamination of the fuel,” he added.
He said it would take several months of tests on the ground as well as simulation to pinpoint the snag in the turbo pump.
Meanwhile, sources in Indian Space Research Organisation (Isro) said the snag would be fixed within a year. The sources said after a smooth lift-off, the performance of the rocket was perfect up to the burn-out of liquid second stage, or 293 seconds into the journey to space. The altitude, velocity, flight path angle and acceleration profile followed the pre-flight predictions. All onboard real time decision-based events were as expected and as per pre-flight simulations. The cryogenic upper stage was switched on at 294.06 seconds, but it developed a snag immediately. The organisation has decided to utilise Russian cryogenic stages for the next two flights of GSLV.