Without a protective spacesuit, a human will quickly lose consciousness, freeze, or desiccate, drifting for millions of years in space.
Whatever you do, do not try to hold your breath. The vacuum of space will suck the air from your body. If there is no air in your lungs, they will rupture. Oxygen in other parts of your body will expand, causing you to swell to twice your normal size. However, you will not explode because your skin is elastic enough to contain your body.
If there is no air in the lungs, they will rupture.
Space is a vacuum, devoid of air. This is different from Earth. In space, there is no atmosphere and no pressure created by air molecules.
Atmospheric pressure determines temperature levels and causes liquids to boil and transition to gas. Therefore, if the external air pressure on a liquid is high, like at sea level on Earth, gas bubbles will struggle to form and rise to the surface to escape. Furthermore, since there is almost no atmospheric pressure in space, the boiling point of liquids is significantly reduced.
According to Dr. Kris Lehnhardt, a NASA space medicine physician: “With 70% of the human body composed of water, this is a serious issue.”
Specifically, without pressure, the liquids in our bodies will boil and immediately transition from liquid to gas. Essentially, all body tissues containing water will begin to expand.
According to NASA’s space travel data book, the vacuum environment in space will suck the air out of a person’s lungs. This causes the victim to suffocate within minutes. Moreover, right after the initial rush of air escapes, the vacuum will continue to draw out gases and moisture from the human body through the respiratory system.
Notably, continuous boiling of water will create a cooling effect. This is because the evaporation of water molecules absorbs thermal energy from the victim’s body, causing parts near the nose and mouth to nearly freeze. In addition, the rest of the person’s body will also become extremely cold, although this occurs more slowly due to the lack of significant evaporation processes.
After reviewing instances of humans and animals exposed to a vacuum environment, an assessment published in 2013 in the journal Aerospace Medicine and Human Performance indicated that these cases lost consciousness within 10 seconds.
Subsequently, some individuals even experienced loss of bowel control, with muscles swelling leading to restricted blood flow to the heart and brain.
Dr. Lehnhardt stated: “No one can survive. Death can occur in less than 2 minutes.”
