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Space suits don’t just make astronauts look cool. Without these special suits, astronauts wouldn’t be able to leave their spacecraft. They wouldn’t be able to walk on the Moon or work outside the International Space Station.

Space is a dangerous place for humans. There is no air to breathe. Space also has high levels of radiation (ray-dee-AY-shun), energy that can move through our bodies and make us sick. Some parts of space are really cold. Other parts are very hot. So astronauts could die in just a few seconds if they stepped outside their spacecraft without their suits. With a space suit, though, astronauts can move around in space for several hours.

Space suits seal astronauts safely inside. A backpack sends oxygen in to let astronauts breathe normally. At the same time, carbon dioxide that astronauts breathe out gets sucked away. The suit also protects them from harmful radiation and fast-moving space dust. Under the space suit is another suit that looks like a pair of tight pajamas with little tubes running through them. Water gets pumped through these tubes to cool off the astronauts. It can get hot in a space suit!

Want to find out more? You can play this game from NASA to learn about the different parts of a space suit.