GSLV failure: ISRO begins data analysis

A group of ISRO scientists have begun looking into the voluminous data at the Vikram Sarabhai Space Centre in Thiruvananthapuram.

Initially, Indian Space Research Organisation (ISRO) Chairman Dr K Radhakrishnan had speculated that “most probably” the main cryogenic engine had failed, awaiting confirmation from an analysis of the flight telemetry and other data.

Though initial sample data had suggested the two smaller ‘verniner engines’ used to control the vehicle altitude had not ignited after take off on April 15, the fractional time lag could have made all the difference for the main cryogenic engine.

“But nothing can be said today; they (scientists) will only be looking at the data and only by Monday we would able to say something definitive (on what plunged GSLV-D3 into the sea),” an ISRO spokesman told Deccan Herald on Saturday.

“As the ISRO chairman has said, there is some doubt on whether the main engine ignited,” the spokesman added.

Imported engines
Of the six GSLV class launches so far – five of them with imported Russian engines - (to put two to 2.5 tonne-class satellites into a Geosynchronous Transfer Orbit), ISRO’s track-record has been fifty-fifty in this critical space mission segment.

The GSLV-D1 launch from the Satish Dhawan Space Centre at Sriharikota though termed successful by ISRO, found its cryogenic stage ‘underperforming’.

Then, GSLV-FO2 that sought to launch INSAT-4C in July 2006 had crashed, raising doubts about the basic vehicle design itself.

‘Fabrication mistake’
Dr Radhakrishnan clarified that the cause of the 2006 failure when analysed, was traced to the failure of one of the strap-on motors, which did not function after 55 seconds after take-off then, as probably “one dimension of one component not fully implemented.”
It was in turn due to a ‘fabrication mistake”, he emphasised.

The ISRO chairman also said that even then there was “no issue with regard to the vehicle design”.

It was the ignition and subsequent performance of the cryogenic engine in the third stage which continued to dog the Space body, Dr Radhakrishnan underscored.