What's it like to die in the vacuum of space?

[Treedbear]

The post on decomposition in the vacuum of space reminded me of a nagging question I have about what it would be like to die in the vacuum of space. The prospect of one's blood boiling and eyes popping out has been enough to keep me from volunteering to go to Mars. But I saw a documentary video somewhere of testing the first space suits in a vacuum chamber where there was a sudden air leak. The guy passed out instantly. He didn't remember much of anything happening when they revived him and no mention of pain. I've heard the pain from suffocation is actually all due to the build-up of CO2 in the blood, not the lack of oxygen. But it all might depend on how quickly it happens. A slow leak might allow one to experience the other more extreme effects.

 

[Cheerful Charlie]

Any number or various aircraft pilots etc have experience high altitude loss of consciousness, and those who survived it have stated they don't remember passing out, which happens quickly, and felt no panic or pain.

https://en.wikipedia.org/wiki/Time_of_useful_consciousness

 

[Loren Pechtel]

Blood boiling and the like is Hollywood, not reality. Your skin is tough enough to hold the pressure in. The water in your mouth boils but that's it. For airless but moderate temperature environments they have actually considered a pressure suit that only covers the head and torso. The arms and legs would be garments that simply squeeze but are not airtight! It would be much easier to work in but wouldn't provide the temperature and micrometeorite protection that current suits do.

The only case where there would be pain is if the environment is vented faster than the air can escape from your lungs. That would be quite painful for the ~10 seconds until you passed out. In this case you would not survive, otherwise you'll be find so long as you get air soon enough and under enough pressure. (Going from cabin pressure to zero can give you the bends.)

 

[bilby]

"Not me. I can survive in space" - K-2SO.

 

[Bronzeage]

The post on decomposition in the vacuum of space reminded me of a nagging question I have about what it would be like to die in the vacuum of space. The prospect of one's blood boiling and eyes popping out has been enough to keep me from volunteering to go to Mars. But I saw a documentary video somewhere of testing the first space suits in a vacuum chamber where there was a sudden air leak. The guy passed out instantly. He didn't remember much of anything happening when they revived him and no mention of pain. I've heard the pain from suffocation is actually all due to the build-up of CO2 in the blood, not the lack of oxygen. But it all might depend on how quickly it happens. A slow leak might allow one to experience the other more extreme effects.

CO2 in the lungs triggers the gasp reflex. This is why it's impossible to hold one's breath until you pass out. However, if there is no oxygen in the atmosphere, the body does not make CO2. There have been many cases of high altitude aircraft losing cabin pressure and no evidence the pilot or passengers had time to realize, or react. Those who left enough remains, showed no sign of panic or other reaction.

A very slow decline in oxygen might allow time to react and possibly correct the problem. However, I have experienced rapid loss of blood pressure while standing, which maybe similar. I hope to never find out, but the first thing to fail are the upper body muscles. It's impossible to raise the arms. Whatever a person needs to do, when oxygen deprivation is sensed, they might not be physically able to do it.

 

[Malintent]

Blood boiling and the like is Hollywood, not reality. Your skin is tough enough to hold the pressure in. The water in your mouth boils but that's it. For airless but moderate temperature environments they have actually considered a pressure suit that only covers the head and torso. The arms and legs would be garments that simply squeeze but are not airtight! It would be much easier to work in but wouldn't provide the temperature and micrometeorite protection that current suits do.

The only case where there would be pain is if the environment is vented faster than the air can escape from your lungs. That would be quite painful for the ~10 seconds until you passed out. In this case you would not survive, otherwise you'll be find so long as you get air soon enough and under enough pressure. (Going from cabin pressure to zero can give you the bends.)

In the situation where the loss of pressure was 'explosive', your lungs would explode like popped balloons... but that isn't even really the most painful bit. The painful part would be your sinus cavities exploding. That would be like a thousand hot knives in your face.

 

[PyramidHead]

Blood boiling and the like is Hollywood, not reality. Your skin is tough enough to hold the pressure in. The water in your mouth boils but that's it. For airless but moderate temperature environments they have actually considered a pressure suit that only covers the head and torso. The arms and legs would be garments that simply squeeze but are not airtight! It would be much easier to work in but wouldn't provide the temperature and micrometeorite protection that current suits do.

The only case where there would be pain is if the environment is vented faster than the air can escape from your lungs. That would be quite painful for the ~10 seconds until you passed out. In this case you would not survive, otherwise you'll be find so long as you get air soon enough and under enough pressure. (Going from cabin pressure to zero can give you the bends.)

In the situation where the loss of pressure was 'explosive', your lungs would explode like popped balloons... but that isn't even really the most painful bit. The painful part would be your sinus cavities exploding. That would be like a thousand hot knives in your face.

There's the infamous case where 4 divers in a pressure chamber were instantly extruded through a 60 cm gap when someone outside it accidentally opened the bell jar before it was fully equalized. Two might have even been sleeping in an adjacent room at the time. Not a bad way to go...