Inside the largest indoor swimming pool in the world.
How does an astronaut train for the strange conditions of space without going to space? Underwater, of course.
To train for the spacewalk, or extra vehicular activity, astronauts work on a full-scale replica of the International Space Station inside of the largest indoor swimming pool in the world at Johnson Space Center's Neutral Buoyancy Laboratory.
Underwater and inside their bulky space suits, astronauts practice the repair and maintenance of equipment with the assistance of support divers.
Before ever setting foot in space, astronauts will have spent more than 100 hours practicing underwater in the NBL.
Explore the NBL below in the 360-degree video from NASA. Click and drag to look around: