Every astronaut who leaves a spacecraft has to wear a specially designed spacesuit. It is called an Extra-Vehicular Activity (EVA) suit and acts like a miniature spaceship. Layers of material protect the astronaut from the Sun’s rays, as well as tiny particles of space dust that travel at hundreds of thousands of kilometres per hour. The suit provides everything that an astronaut needs to survive in space for short periods of time, including oxygen to breathe and water to drink. It also provides heating and cooling, communication devices and toilet facilities.
Astronauts must wear spacesuits whenever they leave a spacecraft and are exposed to the environment of space. In space, there is no air to breath and no air pressure. Space is extremely cold and filled with dangerous radiation. Without protection, an astronaut would quickly die in space. Spacesuits are specially designed to protect astronauts from the cold, radiation and low pressure in space. They also provide air to breathe. Wearing a spacesuit allows an astronaut to survive and work in space.
Spacesuits help astronauts in several ways. Spacewalking astronauts face a wide variety of temperatures. In Earth orbit, conditions can be as cold as minus 250 degrees Fahrenheit. In the sunlight, they can be as hot as 250 degrees. A spacesuit protects astronauts from those extreme temperatures.
Spacesuits supply astronauts with oxygen to breathe while they are in the vacuum of space. The suits contain water to drink during spacewalks. They protect astronauts from being injured from impacts of small bits of space dust. Space dust may not sound very dangerous, but when even a tiny object is moving many times faster than a bullet, it can cause injury. Spacesuits also protect astronauts from radiation in space. The suits even have visors to protect astronauts’ eyes from the bright sunlight.
A spacesuit is much more than a set of clothes astronauts wear on spacewalks. A fully equipped spacesuit is really a one-person spacecraft. The formal name for the spacesuit used on the space shuttle and International Space Station is the Extravehicular Mobility Unit, or EMU. “Extravehicular” means outside of the vehicle or spacecraft. “Mobility” means that the astronaut can move around in the suit. The spacesuit protects the astronaut from the dangers of being outside in space.