The Failure Review Oversight Board (FROB), convened by International Launch Services (ILS), has cleared the Proton Breeze M to return to flight this summer, following its examination of test results and analysis regarding a redesigned engine component. The Russian-built launch vehicle suffered a failure during the March 15th launch of the AMC-14 satellite from the Baikonur Cosmodrome. During that mission, the Breeze M upper stage shut down two minutes before the end of the planned, second burn of its engine. As a precaution, the AMC-14 satellite was released into a lower-than-planned orbit. A Russian State Commission investigated the failure, analyzed possible scenarios, and reviewed the processes, hardware, and systems related to the engine and its supporting systems. Both the Proton booster and the Breeze M upper stage are built by Khrunichev Space Center, which is the primary shareholder of ILS. On April 21 the commission announced its conclusions: that the failure was caused by a ruptured exhaust gas conduit, which led to a shutdown of the turbo pump feeding the Breeze M engine.
The commission recommended a number of corrective actions. The primary step called for Khrunichev to replace the existing conduit with a thicker-walled conduit. ILS assembled an independent FROB to review the Russian commission’s findings in early May. Khrunichev subsequently performed additional modeling, as well as component and certification engine testing, to determine root cause and validate the recommended corrective actions. The FROB reconvened in Moscow last week to review the analysis and test results and agreed the root cause of the failure was the conduit walls were thinner than the minimum specification, which, when combined with other factors, led to the rupture. Khrunichev has successfully completed certification testing of a flight engine with the new conduit. The new conduit is being incorporated in all future engines. The FROB was led by ILS Chief Technical Officer Jim Bonner. Membership included propulsion experts, members of the insurance community, and representatives of the customer for upcoming launches—Moscow, Russia
