What Is Life Like in the Vacuum of Space?





Introduction: What Is Life Like in the Vacuum of Space?

About: The Intrepid Sea, Air & Space Museum is a non-profit, educational institution featuring the legendary aircraft carrier Intrepid, the space shuttle Enterprise, the world’s fastest jets and a guided missile su...

In 1967, a technician testing an Apollo space suit in a vacuum chamber at Johnson Space Center experienced rapid decompression when his suit sprung a leak. When the last of the air left the suit, he passed out. The last thing he reported feeling before passing out was the saliva on his tongue bubbling as it boiled off.

Living in space is very different from living on Earth. For starters, you have to bring all of your air along with you… We will be using a vacuum chamber to simulate the vacuum of space and its effects on our bodies.


  1. Bell Jar
  2. Vacuum pump
  3. Marshmallows
  4. 2 Balloons
  5. Cup full of water

Bell Jar/Vacuum Pump Operating Instructions

  1. Plug in pump.
  2. Attach rubber tubing from pump to the nozzle on base of bell jar. Make sure the valve is OPEN.
  3. Place experiment or item on the bell jar base. Place bell jar on top of base, making sure it is centered to ensure a good seal.
  4. Turn on pump until desired effect is achieved (ie.Water boils, balloon inflates, marshmallow man grows to ghost-busting size)
  5. Turn off pump.
  6. Close valve on base.When finished with experiment, detach tubing from nozzle, and open valve to return pressure to normal.

We will be preforming 3 experiments!

Step 1: Why Is Our Atmosphere Important to Us?

  1. Cup of water
  2. Bell jar
  3. Vacuum pump
  1. Place a cup of room temperature water in the vacuum chamber.
  2. Cover with jar and reduce pressure until water boils.
  3. Uncover and stick your hand in the previously boiling water, note the water should still be room temperature when you put it in ( do not stick your hand in recently boiled water in any other case )


Matter exists as either a solid, liquid, or gas (sometimes plasma). Air pressure from the atmosphere keeps water molecules on Earth’s surface compressed in a liquid state. If there’s not enough atmospheric pressure pressing the water into a liquid state, then there’s also nothing holding the water molecules together. In the vacuum of space the molecules are able to spread out, and begin to boil.

Step 2: What Would Happen to Our Bodies in Space With Out Space Suits?


  1. Bell Jar
  2. Vacuum Pump
  3. 2 Balloons


  1. Place an inflated balloon and a non inflated balloon in the bell jar. The non-inflated balloon will represent us exhaling and the inflated balloon will represent us inhaling.
  2. Cover with jar and reduce pressure. Both balloons should expand, with the inflated balloon getting much larger and possibly popping.


If you ever find yourself about to get sucked into the vacuum of space you should exhale so your lungs don’t explode. Just as the atmospheric pressure on Earth keeps water molecules compressed in a liquid state, the same atmospheric pressure also keeps the air in our lungs from expanding. Without that constant pressure, our lungs would inflate, popping them like balloons.

Step 3: What Would Our Bodies Look Like After Being Exposed to the Vacuum of Space?


  1. Bell Jar
  2. Vacuum pump
  3. 1 Marshmallow


  1. Place the marshmallow in the bell jar
  2. reduce the pressure and watch the marshmallow swell up
  3. Remove the bell jar and watch the marshmallow wrinkle up


The marshmallow represents humans' soft tissues, like those in our skin and organs, which contain water.

A vacuum will cause the water in exposed parts of our body, such as the eyes and mouth, to evaporate quickly, and eventually all the water within us would evaporate, leaving behind what is essentially a dried-out mummy. You can see this in the last picture.

Even if the pressure returns to normal, your body would not be the same after spending too long in space. This is because your cells themselves contain water which would evaporate, and since space is extremely cold, you would freeze and crystallize.



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    19 Discussions


    3 years ago

    Vacuum is Measured in "Inches if Mecury" not a very common or familiar unit of measurement. A vacuum Pump is usually directly affected by how much moisture has been absorbed into the oil. Vac plum oil is hygroscopic meaning it absorbs moisture. In the HVAC industry we change the pump oil very often sometimes every time we use it, but we are seeing way more acids, moisture, and contaminants from the system we are pulling down.

    i don't understand why there is a temperature in complete vakuum... If there is no particle, how could exist anything like cold or warm?

    When someone touch a themos, there is no temperature too. Did i get this right?

    3 replies

    it is not only hot temperature that creates boiling water, the introduction of a vacuum environment to a previously regular atmosphere no longer compresses the water into a liquid state and begins to expand or boil

    yea, i understand why water is boiling in a vakuum, but i still dont understand this "and since space is extremely cold, you would freeze and crystallize.". Does it mean that when you loose an amount of particles that the area would be cold? I've ever thought that the loss of temperature or freezing should not be a top problem in space rather the deforming of the human body and the bursting alveoles.

    thank you for the answer :) and you done a really nice project :)

    Great job !

    Will all vacumn pumps create enough vacumn to boil water or are they rated like aircompressors for certain "pressures"

    1 reply

    While I dont know, I would assume that vacuum pumps are rated by PSI. I cant say whether there is a minimum PSI to create water that boils however, all that is required is the vacuum pump able to suck out all the air of the Bell jar, which I assume all are capable of.

    Great.... Very dramatic and interesting effects.... I have built vacuum chambers to generate 40K volts electron beams... Fun stuff...

    1 reply

    Good Instructable - excellent science teaching topic. The title is a bit deceptive and I wasn't sure what I was going to find.

    1 reply

    The mystery of exploration in Instructables, space, and beyond! But yes thanks for your advice, here at the museum we are just getting familiar with posting here and would appreciate any other advice :)

    ...I always wondered.

    The correct answer as to what happens to a human body in space can be found here. http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970603.html