Third Stage Design Problem Cause of Most Recent Proton Failure

schwit1 writes: The Russian investigation into the latest Proton rocket failure has concluded that the failure was caused by a design failure in the rocket's third stage. The steering third stage engine failed due to excessive vibration as a result of an imbalance in a rotor of a pump unit. While it is always possible for new design issues to be discovered, I wonder why this problem hadn't been noticed in the decades prior to 2010, when the Proton began to have repeated failures.

Comments

two envelopes

[roman_mir]

So I read that this problem dates back to 1988 (so they say). Reminds me of a two envelope joke. A president steps down due to scandals, gives his replacement 2 envelopes. Tells him to open the first one when there is the first serious problem he cannot handle and the second one in case of another problem.

The replacement starts on the job, eventually there is a serious political problem he cannot solve. He opens the first envelope and it says: blame everything on the previous guy. So he does and the problem goes away. Later there is another problem that cannot be solved, the guy opens the second envelope and in says: prepare 2 envelopes.

I think somebody opened the first envelope.

Re:Boston 3rd Stage

[smittyoneeach]

I saw Third Stage Design Problem open for Flaming Reentry in Kalamazoo, MI in '87.