The tragic loss of Virgin Galactic’s SpaceShip Two prompted some comments on whether the program should continue. Loss of life should require an examination of the procedures and decision making process. Independent experts should be asked to look things over in great detail, not to find scapegoats but to make thing better in the future.
It has been pointed out that this is not the first fatal accident in the history of space exploration. Going into space may never be as safe as our television programs and movies make it seem. Bert Rutan, aviation expert, predicts that safety levels might eventually approach those of 1920s vintage passenger planes. It might not ever be possible to have statistics even close to modern commercial jets.
Everything in life has a risk/reward ratio to consider. Fortunately we no longer have to risk our lives just to eat dinner or get a tooth pulled. Driving across the continent is still adventurous, but not dangerous. Occasionally some of us have had to risk our jobs on a technical matter; sometimes those decisions don’t work out so well. I remember having to explain to my-then ten-year-old daughter that our need to relocate was primarily the result of poor decisions on my part.
Gambling is part of human nature. Games of chance have been found in archaeology digs; they are described in ancient texts. Part of our love of sports is that the outcome is not a sure thing. As engineers we do our best to make our projects “sure things,” but there is always going to be some element of risk remaining.
Every test program sees statistical variation; allowable stresses are compromises. Formulas have rounding in them. Materials have defects that may not be fully accounted for in the allowables.
My point is this: You can manage risk but you can’t eliminate it. If something is worth doing, it is worth failing at. And failing more than once.