Not Challenger, but Columbia, and not on Powerpoint, but usage of powerpoint in the organization leading to reduced visibility of data meaning those who received such reports didn't get the really important data.
... and NASA has never admitted to the failings identified by Tufte (or Feynman in the Challenger investigation, for that matter). I own the pamphlet this PDF is the electronic version of, because I thought Tufte earned that copyright (not a sentiment I have about many works, in general I think the terms of both copyright and patent should be reduced to 5 years -- in the interests of replenishing the commons that was the explicit goal of the US intellectual property system).
