A Proton rocket stood up for launch. Photo: TsENKI

[Via Satellite 06-03-2015] The Russian federal space agency Roscosmos issued a statement carried by International Launch Services (ILS) that attributed the May 16, 2015 Proton launch failure to the rocket’s stage three steering engine. The findings come from the Russian State Commission, which traced the mission anomaly to increased vibration loads leading to the failure and loss of Mexico’s Centenario satellite.

Rocket manufacturer Khrunichev and its subsidiaries are developing an action plan to address the most probable causes of the anomaly based on guidance from Roscosmos head Igor Komarov, who chaired the Russian State Commission. This plan includes changing materials used for the turbo pump rotor shaft manufacturing, revising turbo pump rotor balancing techniques, and upgrading the steering engine turbo pump mount to the main engine frame, among other recommendations.

ILS will evaluate the anomaly as well with its own Failure Review Oversight Board (FROB) to review the findings from the Russian State Commission. The FROB will include representation from ILS, customers, insurers and technical experts from industry, and will provide an independent review of the investigation, root cause, and corrective actions required before returning to commercial flight. The company plans to launch the FROB in late June or early July, once a formal summary of the Russian State Commission’s findings has been released to ILS, and after Khrunichev completes the development of the action plan to address the most probable causes. Roscosmos’ preliminary statement noted that the action plan will be developed within one month. After the FROB’s conclusion, its report will be briefed to ILS customers and the launch insurance industry.