For the astronaut shown above, he/she will be fine for now. As long as their space suit is intact, they should not be in any immediate danger of death. However, if their suit were to malfunction for some reason, what would happen next? This has been “explained” before in movies or television shows; but as we all know, those can sometimes be misleading. Instead, let’s look at this situation from a scientific perspective.
First, there have already been studies done on animals to test how long one could survive in a vacuum. For dogs, they would always survive for up to 90 seconds of exposure. However, that number increased drastically for chimpanzees, which could last up to 200 seconds. Of course, both species would lose consciousness quickly, but there did not seem to be any lasting cognitive damage.
With this information, along with general knowledge of space and the human body, we can begin to make some informed guesses as to what would happen to the exposed human in space. In no particular order (or rather, almost all simultaneously), the following events could occur: rapid expansion of gas in the lungs, swelling, unconsciousness, and lack of blood flow. In addition to this, there has only been one person who has ever experienced being inside a vacuum. When asked to describe his last memory prior to losing consciousness, he said that it was the boiling of moisture on his tongue. Although we do not have a definitive answer for our question, we do know for a fact that survival is simply impossible.