Doors -

: Located at NASA’s Vehicle Assembly Building in Florida, these four doors are 456 feet high and take approximately 45 minutes to fully open or close.

: In New York, it is technically illegal for a revolving door to rotate faster than 15 rotations per minute to maintain safety. : Located at NASA’s Vehicle Assembly Building in

: Invented in the 1st century AD by Heron of Alexandria , this early steam-powered mechanism used heat from a temple fire to trigger a series of pulleys that opened the doors. : Located at NASA’s Vehicle Assembly Building in