The Hindu Business Line : GSLV failure due to faulty regulator: Report

(FROM RIGHT) The ISRO Chairman, Dr Madhavan Nair, the Director of Vikram Sarabhai Space Centre Thiruvananthapuram, Dr B.N. Suresh, and the Director of Satish Dhawan Space Centre Shriharikota, Dr M. Annamalai, at the press meet on GSLV-FO2 failure at the ISRO Headquarters in Bangalore on Wednesday. — Sampath Kumar G.P.

Bangalore , Sept. 6

The Indian Space Research Organisation has concluded that a defective regulator in one of the four strap-on engines brought down its GSLV launcher on July 10.

The manufacturing defect was "inadvertent" and escaped the best and established inspection procedures of the space agency, leading to inadequate thrust; loss of the Insat-4C satellite along with the launcher, both worth over Rs 250 crore, according to the Department of Space Secretary and ISRO Chairman, Mr G. Madhavan Nair.

Panel report

He released the key aspects of the report made by a 15-member review committee at a news conference here on Wednesday. The 15-member Failure Analysis Committee was constituted in June to say what went wrong with the home launch from Sriharikota's Satish Dhawan Space Centre.

Mr Nair said, "There is no flaw in the launch vehicle, or its subsystem design, The GSLV programme is not derailed." Only the next lot of hardware will come under bigger scrutiny, especially with a PSLV due in October. It has also set the next GSLV launch for June 2007.

Not divulging how it was dealing with the unnamed Indian supplier of the faulty component, or if it was imposing penalty, Mr Nair said there were two alternative sources. Blacklisting would not be the answer at a time when ISRO had been trying to build up an industry base for ten years and beginning to lean on it so that it could focus on research.

Now, there will be additional tests for engine control and very strict audit of components and sub-systems right from origin through the cycle. ISRO has met all its vendors once and is holding another meeting on September 14 to stress absolute quality control.

ISRO's policy to procure from industry was unchanged as 60 per cent of components are bought from industry. The launcher programme and its components are almost fully indigenous, owing to the long years of US sanctions.

INDIAN VENDOR

Each of the GSLV's seven engines with their regulators - each regulator costing around Rs 1 lakh - came from an Indian vendor. The same company had supplied seven engines - flown on earlier GSLVs nd PSLVs - while the eighth one proved costly. The subsystem was assembled at an ISRO launch vehicle centre.

"This type of defect can come up in a complex system such as the GSLV with seven engines. Some of the liquid engines have a dozen modules that cannot be tested on ground but only in flight. We are not justifying the failure, which should not have happened, but we have taken it as a serious issue," Mr Nair said, adding, "I'm confident such anomalies will not occur in the future."

HOW IT WAS TRACED

The FAC was chaired by Mr K. Narayana, former Director of the SHAR centre. Eight sub-committees pored over flight data and manufacturing documents for over 100 hours. They simulated the same malfunction with water calibration tests and got the same failed flight phenomenon. Through the Department of Ocean Development, two strap-on boosters were recovered from sea. Hunt is on for the culprit S4 booster.

The regulator in S4 had a bore of 17 mm diameter instead of 16 mm, and it allowed far higher flow than the system was designed for. "This regulator has functioned satisfactorily in all the previous 50 engines manufactured and tested so far."

The FAC has recommended:

implementation of strict control on fabrication, inspection and acceptance procedures.

fabrication processes to be critically reviewed and updated.

independent inspection of all critical dimensions of components and subassemblies by in-house agencies.

long-duration hot test on one out of every 20 engines fabricated;

stronger clearance process during the automatic launch sequence phase.

Transponder lease

Mr Nair said ISRO would temporarily lease capacity on a foreign satellite to accommodate the prime user of Insat-4C, the satellite lost on the GSLV in July. It would do this once Sun TV put up its ground system and signalled its readiness.

Sun TV had booked seven of the 12 transponders on 4C to launch its DTH plans.

Meanwhile, it is building INSAT-4CR as a substitute to the lost 4C. It is converting one of its Gsats under assembly into a 12-transponder 4CR. The satellite will be launched from Sriharikota in June 2007.