Turbopump Bearing Cited in Proton Upper-stage Failure

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PARIS — The Dec. 9 failure of Russia’s heavy-lift Proton rocket’s Breeze M upper stage was caused by “a combination of adverse conditions” that damaged a bearing in the engine’s oxygen turbopump, causing the stage to end its final burn four minutes early, International Launch Services (ILS) announced Feb. 12.

Reston, Va.-based ILS, which markets Proton launches, said its own review concurs with a separate board in inquiry by the Russian government, and that Proton will return to flight in March with the launch of the Satmex 8 commercial telecommunications satellite, owned by Satmex of Mexico.

The December failure was the third in 16 months for Proton. That fact, plus the Jan. 31 failure of the Russian-Ukrainian Sea Launch rocket, which destroyed an Intelsat satellite insured for $400 million, is likely to cause space insurance underwriters to take an especially close look at the conclusions of ILS’s Failure Review Oversight Board.

The December failure placed the Yamal 402 satellite into a bad orbit. Satellite builder Thales Alenia Space of France and Italy succeeded in raising the orbit and putting the satellite into service, where it is expected to operate normally for 11 years for owner Gazprom Space Systems of Moscow. The satellite was designed to operate for at least 15 years.

ILS did not detail the conditions that first began to damage the oxygen turbopump bearing beginning with its third ignition. The bearing then failed completely during the fourth ignition, shutting down the Breeze M stage well short of its planned Yamal 402 drop-off point.

 

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