I tried this independently, and have the same result (2.0%). https://gist.github.com/3855660 https://gist.github.com/3855660 And the probability of any rocket

I tried this independently, and have the same result (2.0%). https://gist.github.com/3855660 https://gist.github.com/3855660 And the probability of any rocket engine failing, per launch, is 1 in 3!