At first, moving heavy equipment in outer space might seem like an easy chore. When gravity is low, it becomes possible for astronauts to shove huge objects around with their fingertips. But once a body's in motion, it tends to stay in motion — unless an outside force acts upon it. Let's say that one of the large, metallic chairs on your space station has come unhinged and now it's careening through the vessel. You'll need a skilled hand to slow down and redirect the thing.
That's where air-bearing floors come in handy. As it happens, astronaut trainees have them to practice on at the good old Johnson Space Center. Floors like this are metallic, room-sized, super-smooth and extremely well-polished. They also need to be level. On that score, the one at NASA definitely fits the bill: It's kept level to within 0.003 inches (0.007 centimeters) per foot (0.3 meters) [source: NASA].
So, what does one do with an air-bearing floor? Well, NASA affixes test pads to the bottoms of assorted objects. These create an air cushion between those objects and the floor itself. To paraphrase NASA's official website, that effectively transforms the floor into a room-sized air hockey table [source: NASA].
Astronaut candidates use the surface to prepare themselves for hauling large items through space. It also gives them the opportunity to test out their Manned Maneuvering Units (MMUs), which are personal transportation accessories that function a bit like jet packs [source: Shayler].
But why should NASA's people have all the fun? The European Space Agency's Orbital Robotics Lab has its own air-bearing floor as well [source: Industrial Equipment News].