Do Humans Decompose If They Died in Space?

Astronauts wear special space suits to be safe from danger in space. The danger is like radiation that can damage the body mostly from the sun to basic needs such as oxygen for the astronaut to breathe. But if humans die out there, what happens to their bodies? Let’s dig deeper.

Death in Space
Copyright: LuigiDonatello on Youtube

Astronaut Spacesuit

Simply put, a spacesuit is divided into several parts namely the body, arms, palms, feet, and helmets. Part of the helmet itself is made in such a way that astronauts remain protected but can still have the widest possible view.

Spacesuit has several layers, from the oxygen barrier layer to the layer that protects from high speed particle impact.

Astronaut Bruce McCandless II
Copyright: NASA

The speed of particles in space can range from a few meters per second to several kilometers per second. However, the majority of these particles are small so they are not too dangerous to astronauts or satellites in space.

The spacesuit is designed to withstand extreme temperatures ranging from -156 ° C to 121 ° C. This can happen because the spacesuit has a mechanism to regulate the temperature inside. Besides, there is usually an oxygen cylinder that astronauts carry as an oxygen supply into the spacesuit.

Then What If The Astronaut Dies In Space?

If you think about it, this includes questions with conditional answers. Simply stated, these conditions include:

1. Oxygen

Spoilage/decomposer bacteria only work well if there is still oxygen. If the oxygen in the spacesuit is used up, it will be very minimal, even if there is no decay on the astronaut’s body.

2. Temperature

Over time, the spacesuit temperature regulator can die / damage. If the temperature is too low then decomposer microorganisms will be less active or even inactive so that no decay occurs. Meanwhile, if the temperature is too high, then the decomposer microorganisms will die so that no decay occurs anyway. Therefore it needs the right temperature rather still decay can occur.

3. Moisture

Without water, decomposer microorganisms will not be able to survive. Conversely, the more water content, the decay process will be faster.

How’s the Example?

So, regarding the answer to whether the bodies of astronauts rot in space depends very much on how the cause of death. For more details, consider the following cases.

Case 1

An astronaut is in a vacuum, oxygen levels in the spacesuit are so low that it makes him faint. The astronaut could not be saved so he died. What will happen? If there is still oxygen in the spacesuit, decay will begin to occur within at least 24 hours after death. However, if then the oxygen has run out, decay will slowly stop. When the temperature control system turns off, the overall temperature will become so cold that the astronaut’s body will freeze.

Case 2

An astronaut is doing a spacewalk, which is doing activities in space outside the satellite/station/aircraft. However, he was hit with a high-speed space object so that his helmet broke. What will happen? Spoilage will not occur. What happens when the human body is exposed to a vacuum is as follows. All air, including the body, as in the lungs, will come out. Water on moist surfaces such as lips and eyes will evaporate to dryness and stiffness like freezing. His body will swell, vaporize sweat and gas. He will lose consciousness in just 15 minutes. Besides, it takes approximately 1 hour for his body to cool like space temperature.

Case 3

An astronaut is teleported into space so he is suddenly in space without a spacesuit. What will happen? No decay occurred. What happens is more or less the same as case 2. Only without a spacesuit, his body will be exposed to severe radiation, especially radiation from the sun.


If asked whether humans decompose if they die in space, the answer depends on how they died and the conditions at that time, especially temperature, oxygen levels, and water.

Sources and References:

  1. What Is a Spacesuit? – NASA
  2. What Happens to the Unprotected Human Body in Space? – CNET
  3. Space Suit – Wikipedia
  4. The Effects of Temperature, Water and Oxygen Availability on Decay – BBC Bitsize
  5. The Stages of Human Decomposition – Aftermath
  6. Micrometeoroid – Science Direct
  7. What Does Happen If an Astronaut Dies in Space – Aerospace Engineering
  8. Will We Ever Visit Other Stars? – VSauce

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