TechRepublic visited the Neutral Buoyancy Lab at the Johnson Space Center where astronauts train for spacewalks.
This giant pool is an important piece of training for astronauts who will be completing extra vehicular activities (EVAs), or spacewalks. The pool prepares them for working in a (mostly) weightless environment, as neutral buoyancy refers to the equal tendency to float or sink.
NBL opened in 1995. When they initially started filling it, they turned on the water full blast and the city of Houston's water pressure dropped to 0, prompting a call to NASA as to what what going on.
Training for spacewalks includes not just those who will be outside the International Space Station, but the crew monitoring and the crew operating the robotic arm. The pool has its own control room, shown here.