Briz-M engine bearing breakdown is possible cause of problems in Yamal-402 launch - newspaper

A damaged bearing of the Briz-M upper stage engine's turbo-pump is the main theory why the Yamal-402 telecom satellite failed initially to be inserted into the desired orbit slot, Kommersant reported on Tuesday.

A working group led by Federal Space Agency deputy head Alexander Lopatin has analyzed telemetric data that shows the defect in the upper stage's engine, it said.

"A mechanical breakdown of a bearing in the turbo-pump of the Briz-M engine was the main reason," a source in the commission investigating the abortive launch told the newspaper.

"The engine was killed automatically as soon as that happened. Hence, it worked four minutes less than intended," the source said.

In his words, telemetric data refuted the theory of a mistake in the launch mission plan.

The newspaper said that the Federal Space Agency would publish final results of the investigation before the end of this year.

A Proton-M rocket with a Briz-M upper stage and Yamal-402 blasted off Baikonur on Dec. 9.

The upper stage and the satellite separated from the Proton ten minutes after the takeoff. The satellite was supposed to reach a geostationary orbit of 35,786 kilometers with the inclination of 55 degrees. The upper stage engine worked for four minutes less in the final orbit trim burn, which prevented the satellite from reaching the designated position. It was inserted in the orbit slot later on with impulses from its own engines.

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