Although it stood to reason that the weather had made the O-rings less elastic—that was a matter of elementary physics—he could not prove that the cold had caused the leaks, because no one had ever tested the seals’ effectiveness across a range of temperatures. In the strict regime of NASA’s Flight Readiness Reviews—and especially the rigidly Teutonic traditions of the Marshall Space Flight Center—this absence of causal evidence was unscientific, tantamount to a hunch.
