An old physics teacher of mine has a conspiracy theory.
My physics teacher, Mr. Hasson, once helped run a company that made a component for the space shuttles. O-rings, actually. His company explicitly told NASA that the O-rings wouldn't function properly at certain temperatures. NASA apparently ignored this warning and...well...you've all heard of the Challenger disaster, right?
During the investigation after the explosion, one of the more prominent physicists who was participating in the investigation, Richard Feynman, was invited to the house of an Air Force officer. After they had eaten, the Air Force officer asked Feynman if he could take a look at his son's broken RC car. Feynman looked at the RC and realized that the O-rings of the RC had been warped by high/low temperatures, resulting in its malfunction. This set Feynman on the path to the conclusion that the shuttle's O-rings malfunctioned, resulting in the destruction of Challenger.
Here's where the conspiracy theory comes in.
Why the hell would the RC just happen to have warped O-rings? Why did the high ranking Air Force officer need Feynman's help to figure this out?
Mr. Hasson maintains that the Air Force officer, and NASA, knew that there was a danger in launching the shuttles outside of a given temperature range. My old teacher claims that the Air Force officer showed Feynman the RC with a bad O-ring because the officer knew that Feynman would arrive the conclusion that the O-rings had been messed up. Furthermore, the officer did this because he was too scared to come forward himself. If he did, it would mean that NASA had willing taken unnecessary and forseeable risks with the lives of the Challenger crew, and all the blame would have been dumped on the government and NASA.
That's my old physics teacher's view on it.