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The Dnepr launch vehicle (the SS-18 missile conversion variant) with a group of spacecraft aboard was launched from Baikonur Cosmodrome on July 26, 2006 at 22 hours 43 minutes, Moscow Standard Time. The launch ended up in a failure during the 73,9th second of flight.
A Ministerial Committee (hereinafter the Committee) chaired by a member of the Russian Academy of Sciences Nikolay A. Anfimov has been set up by the state authorities of Russia to investigate the cause of the Dnepr LV mission failure. Representatives of the Russian Space Agency, Russian Ministry of Defense, SDO Yuzhnoye (the rocket primary design and development entity), the State Enterprise Production Association Yuzniy Machine Building Plant (the rocket primary manufacturing entity), the Scientific and Production Enterprise KHARTRON-ARKOS (the rocket control system primary entity), ISC Kosmotras, FSUE TZNIIMASH and other organizations joined the Committee as its members.
The Committee has come to the conclusion that the emergency was caused by a short-time (0,26 sec) malfunctioning of the pumping hydraulic drive of combustion chamber #4. The first stage thrust vector is controlled by the nozzle gimbal suspension. The control malfunctioning brought about the disturbances, which led to the roll instability, excessive dispersions of the yaw and pitch angles, and, eventually, the issuance of a command for the emergency shut down of the motor.
It has been determined that the hydraulic drive short-time in-flight malfunctioning occurred because of the heptil overheating inside the pipeline running from the motor to the hydraulic drive. And the heptil overheating was caused by the heat insulation damage resulted from non-compliance with the design and manufacturing documentation.
The Dnepr LV launch failure study has not detected any flaws related to the long-term operation of the baseline SS-18 missiles.
Based on its conclusions the Committee has issued the following recommendations in regards to the Dnepr LV operation: to verify the condition of heat insulation of the heptil carrying pipelines of the SS-18 missiles that are being decommissioned and used for the spacecraft launch missions for compliance with the design and manufacturing documentation and, if necessary, modify them.
The conclusions made by the Committee were delivered to the State Committees of Russia and Kazakhstan established with the aim to investigate the Dnepr launch failure consequences.
18.09.2006 |
