Bending Under Pressure
Maintaining proper pressure inside a spacesuit is essential to astronaut survival during a spacewalk. A lack of pressure will cause body fluids to turn to gas, and resulting in death in a few seconds. While making spacewalks possible, pressure produces its own problems. An inflated spacesuit can be very difficult to bend. In essence, a spacesuit is a balloon with an astronaut inside. The rubber of the balloon keeps in oxygen that is delivered to the suit from pressurized oxygen tanks in the backpack. But, as pressure inside the balloon builds up, the balloons walls become stiff, making normal bending motions impossible. Lack of flexibility defeats the purpose of the spacewalk- mobility and the ability to do work in space.
Spacesuit designers have learned that strategically placed breaking points at appropriate locations outside the pressure bladder (the balloon-like layer inside a spacesuit) makes the suit become more bendable. The breaking points help form joints that bend more easily than unjointed materials. Other techniques for promoting bending include stitching folds into the restraint layer that spread apart and contract with bending and building joints into the restraint layer like ribs on vacuum cleaner hoses.
Materials and Tools Checklist