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Against the Elements
You might be able to get by for a little while without a raincoat in a storm or a winter coat in snowy weather. But none of us could survive the harsh atmosphere of space for even a second without the right clothes.

Astronauts must wear protective gear while outside their spacecraft.Image to right: It doesn't look dangerous in space, but astronauts face many hazards. Credit: NASA

Astronauts don't need to wear special clothing when they are living and working inside the Space Shuttle or International Space Station (ISS). Aside from the lack of gravity, the inside environment is very similar to the Earth's. Astronauts work in comfort, wearing shirts, pants and often no shoes. But when someone needs to go outside for a space walk, things get more complicated.

Humans sent out into space without a space suit would become unconscious in 15 seconds, and suffer permanent brain damage in just 4 minutes. The temperatures on Earth may dip to 32 degrees Fahrenheit on a chilly day. But in space, it can get down to 148 F below zero or rise to 248 F. With those temperature extremes, it's important for astronauts to put on protective gear before they go out to work.

Spacesuits form a self-contained environment for astronauts exploring outside their spacecraft.Image to right: When astronauts walk in space, their space suits form a self-contained environment. Credit: NASA

Other external elements pose a danger to astronauts. Orbiting debris traveling at high speeds can cause great injury in space. The glare from direct sunlight can damage the eyes. Solar radiation emitted from the Sun can cause radiation sickness and increase the risk of cancer.

An obvious reason astronauts need protective gear in space is to get oxygen. The amount of oxygen in space is so small, and the air pressure so low, that without a space suit to compensate for these differences people wouldn't be able to breathe, and the lack of pressure would cause body fluids to vaporize and escape.

Space suits provide life support for astronauts.Image to right: Life support systems are part of the structure of space suits. Credit: NASA

NASA's Mission Control crew doesn't want astronauts taking any unnecessary risks in space. All of the astronauts wear an Extravehicular Mobility Unit (EMU), commonly called a space suit, when they venture out from the safety of their spacecraft.

EMUs provide temperature control and ventilation with a one-piece mesh spandex undergarment. Water cooling tubes keep astronauts comfortable while working in space. This suit also includes a drinking bag that holds water, a urine collection device, a communication headphone and microphone, and instruments that monitor vital signs.

Many different astronauts can use the same space suits. The various parts are interchangeable, depending on the size of any given space walker. They feature special equipment such as fingertip heaters, a cooling system shutoff, helmet-mounted flood lights, and a jet-pack that can help astronauts return to their craft, should they accidentally break loose from the tethers that connect them to the spacecraft.

EMUs protect our space explorers during the critical work done outside of the warm confines of the ISS. With these stellar suits, astronauts can work towards NASA's vision and make the harsh elements of space a little friendlier.
NASAexplores and NASA's John F. Kennedy Space Center