We all know that outer space is a vacuum with no breathable air or pressure. But have you ever wondered how long you could survive in space without a spacesuit?
A person would certainly die without a spacesuit, but it would not be instant, he or she would get a minute or two to be rescued.
Here’s What Would Happen in Those Couple of Minutes
Lack of oxygen would suffocate you to death. All the oxygen inside your body would be sucked out after 15 seconds, and you would lose consciousness. If you tried to hold your breath, you would be in big trouble due to lack of outside pressure. You would rupture your lungs like scuba divers when they ascend too quickly from deep waters.
The next likely thing to happen would be the formation of bubbles in body fluids called Ebullism. The bubbles would form throughout your body instantly, like bubbles inside the liquid when you open a soda bottle. Due to low pressure in the vacuum of space, the boiling point of the fluids in your body would be below the body’s normal temperature (37° C), resulting in the formation of gas bubbles in your fluids. Though you wouldn’t explode due to the elasticity of the skin, your body would swell up to twice its normal size.
Now, you would lose consciousness, but in those last a couple of minutes, you would be bombarded with all that raw, unfiltered UV radiation from stars and the sun. It would damage your DNA, leading to mutations that would likely cause death due to radiation poisoning or cancer.
Although the space environment is typically extremely cold, freezing to death is not an immediate risk in outer space as the heat does not transfer out of the body very rapidly in the absence of a medium such as air or water.