 So luck is pretty important. You could be the only person that has a particular idea on a particular day. Now where does the idea come from? Nobody knows where ideas come from. They come from our thought process, they come from conversation with people, they come from stimulation from the environment, but who knows. Anyway, when an idea comes to you, you may be the lucky one, you may be the only one that ever will have that idea. So you say, well that's a good idea, maybe I'll talk to some people. And then of course there's the luck of, did you do it right? When you stand out there at the launch pad and you see that your life work is standing on top of hundreds of thousands of pounds of explosive material, and you're trusting that everyone did their job well so it's going to work, you know that there's some luck involved in that because we could all make a mistake. And we do make mistakes, but usually we catch them. So that's part of our NASA process is we make mistakes and we catch the mistakes in our test programs. So that's how come we usually have good luck. We test and test and test.