McLEAN, Va., July 6, 2006 – A review board convened by International Launch Services (ILS) concurs with the findings of a Russian commission that investigated the Proton Breeze M vehicle failure during the mission to launch Arabsat 4A satellite.

ILS suspended missions with the Breeze M upper stage after the Feb. 28 launch failed to place the Arabsat 4A satellite into the correct orbit. The Proton's first three stages operated properly, but the Breeze M's main engine shut down about four minutes prematurely during the second of four scheduled burns and the satellite was released into a low orbit. It was the first failure in 14 flights of the Breeze M. The satellite was de-orbited March 24.

A Russian State Failure Commission launched an investigation immediately after the anomaly. After reviewing telemetry data and conducting test firings, the commission concluded in late April that the failure was associated with a reduction in flow through the engine oxidizer system on the Breeze M. The most probable cause was a foreign particle that entered a fuel line in the engine, blocking the nozzle of the hydraulic pump, the commission stated. There is no evidence to suggest that any other subsystem of the Breeze M upper stage was involved in the failure, the commission said.

ILS convened a Failure Review Oversight Board (FROB) to review the Russian commission's findings. Members included Eric Laursen, ILS vice president and chief engineer; senior propulsion experts; and representatives of customers and the insurance industry.

After thorough reviews and meetings with the Russian State Commission, in accord with U.S. and Russian government technology control regulations, the FROB concurred with the commission's findings. Further, the FROB also reviewed the commission's corrective action plan that, among other things, calls for additional inspections during the Breeze M engine manufacturing process. The FROB is satisfied that these corrective actions will safeguard against the recurrence of the anomaly.

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