> but the people they are fighting against have a lot higher success rate at this point, and a LOT more experience. I just don't think this is true outside a f

> but the people they are fighting against have a lot higher success rate at this point, and a LOT more experience. I just don't think this is true outside a few areas. SpaceX has built a team that did a lot of these things and not that long ago. Most people working on the Ariane, SLS were not around when these rockets and engine were built originally. Remember that SLS is just a lot of old parts stitched together a different way (with the explicit goal that this would be cheaper, ironically). So in terms of building new rockets I think its absolutely clear that SpaceX has the most experience of anybody. > SpaceX is changing the game, and reducing the cost of getting to space might be what causes the next great age in humanity, but at the same time I have to say that I'm relieved that the James Webb telescope is going up on Ariane 5. I mean while that is a fair sentiment, we are comparing on of a rocket that has virtually not evolved for a very long time against a rocket that was created by a company that didn't even exist for most of the time Ariane 5 flew. The more interesting question is if you would put more trust in the Ariane 6 and I think not, that rocket will have to show that it can build the same kind of reliability history. > And if you worked at NASA and really want the absolute best, I can see why you'd want to avoid the "cheap" option, even if you agree that they might one day be better. But that is one very, very specific mission, I see absolutely no issue with Falcon 9 launching most NASA payloads. They already have launched stuff like TESS for example. I mean the reality of the situation is that Falcon 9 is a human rated rocket, the Ariane 5 or Ariane 6 will both not be human rated and that would indicate Falcon 9 has some additional safety requirements.