The astronaut can be an independent spacecraft. The original spacewalker was designed for the US space shuttle, but the former Soviet astronauts later used similar devices. The space walker looks like an armchair, 125 cm high and weighs 100 kg. The space walker is connected to the back of the space suit, which has two iron arms with all control buttons. When the astronauts control these buttons, they can move to either side at speeds of up to 20 meters per second. The motion of the spacewalker comes from small nozzles that allow the nitrogen in the two high-pressure tanks to be ejected outward. The spacewalker enables astronauts to move freely in space.