August 8, 2013 – A summary of the findings on the root cause and corrective action plan following the failure of the July 2 Proton M/Block DM mission with three GLONASS navigational satellites for the Russian Federal Government has been released to International Launch Services (ILS) upon being cleared by Russian security.

The summary indicates that the most probable root cause of the failure was due to the improper installation of the three yaw angular rate sensors located on the Proton launch vehicle, which caused the vehicle to deviate from its flight path shortly after lift-off.

The ILS Failure Review Oversight Board (FROB) will begin on August 9 and will provide an independent review of the investigation, probable root cause and corrective actions required prior to return to commercial flight, in accordance with U.S. and Russian government export control regulations. The FROB will tentatively conclude by August 16.

The FROB consists of ILS customers, industry subject experts, and insurance industry representatives. After the conclusion of the FROB, the FROB report will be briefed to ILS customers and the launch insurance industry.

Additional information will be provided as it becomes available.

Related Link: Previous Updates on Russian Federal Proton GLONASS Mission Failure


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