[discostu]

They didn't emerge stronger after Challenger. The post Challenger NASA was timid and fearful, and that's continued to this day. Remember it was only a few months ago that NASA released their study on Mars exploration that basically boiled down to "it would be dangerous, so we probably shouldn't". I hope NASA emerges with some cajones but the historical evidence says they get more chicken every time something bad happens.

[RightWhale]

The post Challenger NASA was timid and fearful

Absolutely correct! Space travel is inherently dangerous; there is no way to guarantee perfect safety. Even so, there is no shortage of volunteers to take on these missions. I would fly the Space Shuttle right now; I assume you would, too. We really have to get on with exploration of space, going back to the moon, going to Mars, mining asteroids. Big goals. The ISS is okay for what it is, but it isn't a big goal. We can debate which to do first, Mars, moon, or asteroids, but we ought to pick one or all and get on with it!