Neutral Buoyancy Laboratory - one of the world's largest astronaut training pools

NASA Johnson Space Center's Neutral Buoyancy Laboratory (NBL) is one of the world's largest indoor pools used to train astronauts for spacewalks. The pool is approximately 202 feet long, 102 feet wide, and 40 feet deep and holds about 6.2 million gallons of water; it supports full-scale mockups of International Space Station modules for extravehicular activity practice. The facility is located on the Johnson Space Center campus and is used for underwater simulations of microgravity.