Comment by gist

For a future blog post, as a non engineer I'd be curious how an engineering team designs a system (like those you detail) and others in that mission when there is no way to test them fully in advance of the mission. I know that's a very basic general question but essentially how to you know a hypothesis you can't test works (even with various degrees of pre-testing and scientific knowledge. I am not talking about that 'we know that sound travels' or things that are known but things you are pretty sure but not absolutely sure until you have actually done them. (I do know things are done in stages with various testing and small steps but I guess I am unclear on how once lives are at stake (meaning liftoff from the moon) you really know 'it will all work as planned' meaning to a super high degree of likelihood enough to take the risk.