The 30th anniversary of the tragedy of Challenger

It has been 30 years since the Challenger crew tragic death. The reason was worn O-ring with safety margin three times the face value. Costing less than $ 100 including installation.

As the great physicist of our time winner of the Nobel Prize in 1965 Richard Feynman (1918-1988): In NASA lacked the pessimists! and added: Nature can not be fooled!
 
Pessimists even though people are not popular, but very necessary, and everywhere. Sure, not without reasons, a management and performers are often deceived by past successes.
Let us not slacken their vigilance engineering, and as a bona fide employees of various organizations, let us ask ourselves whether we have done everything for total security?
Good luck to you all and good nights before the start!
Yours sincerely,
Alexander.