Today, the astronauts on the International Space Station spacewalk exclusively in special suits (EMU).
Since the Earth's environment is recreated directly inside the suit, it allows you to crawl on the vacuum in relative safety.
That provides a space suit?
Atmosphere pressure. Skafandr provides air pressure to the fluid in your body remained in a liquid state. In other words, prevents bodily fluid from your boiling. The pressure in the suit is much lower than the earth, so that the suit is not turned into a balloon and remained so flexible as possible.
Oxygen. Space suits must supply pure oxygen due to low pressure. Normal air - 78% nitrogen, 21% oxygen and 1% of other gases - estremalno can lead to a low oxygen concentration in the lungs and blood out of the low pressure.
Adjustable temperature. To cope with the extreme temperatures, most suits reinforced insulation laminated fabric (neoprene, gorteksom, dacron) and protected with reflective outer layers (Mylar or white fabric) away from direct sunlight.
Protection from micrometeorites. Space suits are made from a durable fabric in several layers (Dacron and Kevlar). These layers prevent the suit from breaks on the exposed surface of the spacecraft.
What will happen to your body?
Space towards us very unfriendly. If you find yourself outside of the miracle of the spacecraft, the ISS or the moon or Mars, forgetting the suit, the following will happen:
You will lose consciousness within 15 seconds due to lack of oxygen.
Your blood and other body fluids to boil, and then freeze due to lack of air pressure.
Tissue (including skin tissue, heart and other organs) has expanded because the liquid will boil.
Temperature in the shade of -100 degrees Celsius, and the sun - 120 degrees. You will have to freeze or substantially tan.
You irradiate all possible sunlight radiation and charged particles from the solar wind.
You are bombarded with tiny particles of dust and stones at high speed, well, or orbital debris, which next to the satellite or spacecraft may be enough.
The human body absolute vacuum can survive for a few seconds at most. Thus, the scene in the "Space Odyssey" when Dave jumps in the vacuum of space and dives into the space station, it may be feasible in reality. But a few seconds everything can turn not the best way. Do not take chances, take care of yourself.