The performance of the GSLV-F06 flight of December 25, 2010 (with GSAT-5P Satellite onboard) was normal up to 47.5 seconds from lift-off. The events leading to the failure got initiated at 47.8 seconds after lift-off. Soon, the vehicle started developing larger errors in its orientation leading to build-up of higher angle of attack and higher structural loads and consequently vehicle broke up at 53.8 seconds from lift-off (as seen visually as well as from the Radars).
As per the Range safety norms, a destruct command was issued from the ground at 64 seconds after lift-off. The flight was hence terminated in the regime of the First Stage itself.
Soon after this, Dr. Radhakrishnan, the Chairman ISRO constituted a Preliminary Failure Analysis Team under the chairmanship of former Chairman, ISRO Dr. G. Madhavan Nair, to conduct a preliminary analysis of the flight data, along with members of the Launch Authorisation Board, and Mission Readiness Review Committee as well as senior Project functionaries of GSLV Project and Experts.
The finding of the Preliminary Failure Analysis Team is that the primary cause of the failure is the untimely and inadvertent snapping of a group of 10 connectors located at the bottom portion of the Russian Cryogenic Stage. Some of these connectors carry command signals from the onboard computer residing in the Equipment Bay (located near the top of the vehicle) to the control electronics of the four L40 Strap-ons of the First Stage. These connectors are intended to be separated only on issue of a separation command at 292 seconds after lift-off. The premature snapping of these connectors has led to stoppage of continuous flow of control commands to the First Stage control electronics, consequently leading to loss of control and break-up of the vehicle. The exact cause of snapping of the set of connectors, whether due to external forces like vibration, dynamic pressure is to be analysed further and pin-pointed.
Chairman ISRO has now constituted a Failure Analysis Committee to (i) carry out an in-depth analysis of the flight data of GSLV-F06 as well as the data from the previous six flights of GSLV; (ii) establish reasons for the failure of GSLV-F06 flight and; (iii) recommend corrective actions on the GSLV vehicle including the remaining one Russian Cryogenic Stage. The Failure Analysis Committee chaired by Former Chairman ISRO Dr. G. Madhavan Nair has 11 Experts drawn from within ISRO and outside.
Chairman ISRO has also constituted a Programme Review and Strategy Committee to look into (i) the future of the GSLV Programme and assured launch for INSAT/GSAT Series, INSAT-3D as well as Chandrayaan-2 (ii) realization and operationalisation of indigenous Cryogenic Stage (iii) strategy for meeting the demands of communication transponders in the immediate future. Dr. K. Kasturirangan, former Chairman ISRO and presently Member of the Planning Commission will be chairing this seven member Committee.
These two Committees have been requested to submit their Reports by the end of January 2011. Subsequently, the Reports of these Committees will be presented to Eminent National Experts including Dr A.P.J. Abdul Kalam, Prof. M.G.K. Menon, Prof. Yash Pal, Prof. U.R. Rao, Dr. K. Kasturirangan, Dr. G. Madhavan Nair, Dr. R. Chidambaram, and Prof. R. Narasimha.
Further, a Panel chaired by Dr. S.C. Gupta, former member of Space Commission will be guiding and facilitating an internal exercise by Chairman, ISRO, eliciting views from the ISRO community at all levels to gear up for the complex and challenging space missions ahead.
ISRO plans to complete these reviews and internal exercises by end of February, 2011.
Source: http://www.isro.org/pressrelease/scripts/pressreleasein.aspx?Dec31_2010
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