Jamie found a story of NASAs Giant "Science" Roller Coaster. It will be used as an escape chute on rocket launchpads, and will be the 3rd highest drop in the world. More like the Cedar Point Demon Drop than a roller coaster, but still, I'd ride it.
If it happens once, it's a bug. If it happens twice, it's a feature. If it happens more than twice, it's a design philosophy.