Hoax: Space Shuttle

Company reorganisation seminar today began with story of how the range of the Space Shuttle was indirectly determined by the width of a horse's ass. I'd heard the story before, but a couple of details didn't ring true. The railway tunnel could have been made wider to take bigger rockets (or, as Robb says, they could have built the rockets closer to the launch site). Snopes says it's false (or "True, but for trivial and unremarkable reasons").