Jan 3, 2011
NEW DELHI — The Indian Space Research Organization (ISRO) says the Dec. 25 failure of a Geosynchronous Satellite Launch Vehicle (GSLV-F06) carrying the GSAT-5P satellite was caused by the untimely and inadvertent snapping of a group of 10 connectors located at the bottom portion of the rocket’s Russian-made cryogenic upper stage.
Some of these connectors carry command signals from the onboard computer — located in the equipment bay near the top of the vehicle — to the control electronics of the four L40 strap-ons of the first stage. The connectors are intended to separate at 292 sec. after liftoff. The premature termination of the connectors interrupted commands to the first-stage control electronics, leading to loss of control and breakup of the vehicle, according to ISRO. The exact cause of the connector malfunction remains to be determined.
The 2,130-kg. (4,700-lb.) GSAT-5P was to replace the INSAT-2E satellite, launched in 1999. Carrying 24 C-band transponders and 12 extended C-band transponders, it was the heaviest satellite lofted by an Indian launch vehicle.
The performance of the GSLV-F06 flight was normal up to 47.5 sec. from liftoff, when the rocket began to lose its orientation, leading to higher structural loads and finally the breakup of the vehicle at 53.8 sec. from launch. A destruct command was issued from the ground at 64 sec.
- Neelam Mathews