How much of him being a hero is a coincidence? Did he refuse to sign the previous launches? Did NASA have reasons to believe that the launch could be successful? How much of a role does probability play here. I mean if someone literally tells you something isn't safe, especially the person who made it, you can't tell him it will work. There is somekind of bias here.
His decision would have been questioned after the fact, he would defer to information from levels below, and this would recurse until responsibility had dissipated beyond and any personal attribution. The same pattern happens in every org, every day (to decisions of mostly lesser affect).
The key point—at least from my read—were the follow up actions to highlight where information was intentionally ignored, prevent that dispersion of responsibility, and ensure it didn't happen again.
Unfortunately, while that specific problem did not happen again, the general cultural changes that were supposed to happen had been lost 15 years later. The loss of Columbia in 2003 was due to the same kind of poor decision making and problem solving process that was involved in the loss of Challenger.
So NASA probably didn’t look closely into the engineering, in particular when launch is tomorrow.
The form he talked about was one that, if not signed, would mean that the launch would not happen. I can't remember if it was an internal form or not, but it doesn't really matter in that context.
Since NASA needed that form signed, he was under intense pressure to actually sign it both by NASA and his company. Someone else from the company not on site signed it.
Yes, they did. NASA had been told by Thiokol the previous summer about the O-ring issue and that it could cause the loss of the Shuttle--and ignored the recommendation to ground the Shuttle until the issue was fixed. The night before the launch there was a conference call where the Thiokol engineers recommended not launching. Detailed engineering information was presented on that call--and it was information that had already been presented to NASA previously. NASA knew the engineering information and recommendation. They chose to ignore it.
Basically, the "powers that be" wanted the launch and overruled the concerns of the engineers. They forced the launch against better judgement.
(Think of the, "Oh, that nerd is always complaining, I'm going to ignore them because they aren't important," attitude.)
None. He knew the right thing to do and did it despite extreme pressure.
> Did he refuse to sign the previous launches?
I don't know about him personally, but Thiokol, at the behest of McDonald and other engineers, had sent a formal letter to NASA the previous summer warning about the O-ring issue and stating explicitly that an O-ring failure could lead to loss of vehicle and loss of life.
> Did NASA have reasons to believe that the launch could be successful?
Not valid ones, no. The launch took place because managers, at both NASA and Thiokol, ignored valid engineering recommendations. But more than that, NASA had already been ignoring, since the previous summer, valid engineering recommendations to ground the Shuttle until the O-ring issue was understood and fixed.
> I mean if someone literally tells you something isn't safe, especially the person who made it, you can't tell him it will work.
You literally can.