I don't know specifics here, except to say that the important thing is not whether or not he warned of the disaster or withheld his consent, but how _infrequent

I don't know specifics here, except to say that the important thing is not whether or not he warned of the disaster or withheld his consent, but how _infrequent_ that event was. Did he sign off on STS-61-C? My understanding is that there were numerous warnings about the Challenger, but the same warnings had been made constantly for every single launch. Sometimes they resulted in delays, etc., but the engineers and managers in charge of the launches had ample evidence of predictions of failure not being borne out because the system was resilient to them. Similar to warnings about 9/11, or Fukushima, or the 2008 GFC, there were people who predicted them. But, like the saying goes "they predicted 25 of the last 7 recessions". I can't say whether McDonald fits this mold, but if he did not -- if he made an unusual prediction -- then that should be front and center here. [1] https://en.wikipedia.org/wiki/STS-61-C https://en.wikipedia.org/wiki/STS-61-C