Not just talk: Mechanical counterpressure suit - Wikipedia
Given all the really wacky (and expensive) things that were done in the early days of flight, high altitude flight, and space exploration I can’t believe that somebody somewhere didn’t throw just a neck sealable helmet on a chimp and chunk it into a vacuum to see what happened.
Because, for short term emergencies, particularly when every ounce counts and space it a premium it sure would be nice to just have to haul a helmet around rather than full blown spacesuit. Hell, if nothing else you’d think somebody would be motivated by that pod to ship transfer through the vacuum of space scene in A Space Odyssey 2001 to try variations on that.
The Russians Cosmonauts that died on decent from orbit due to a stuck valve might have been saved by a helmets better than nothing approach for starters.
That might buy a few extra minutes, but I imagine this system as a whole would be quite punishing on the body - especially the delicate tissues of the lungs.
Um, space is the insulator. I don’t think there are many better insulators than a vacuum. I’m not a rocket scientist, though.
Yes, when your body is getting rid of heat by radiating it away rather than through conduction/convection the heat loss may be less than just being in chilly air. Somebody should do the calculation . Loss due to radiative cooling compared to how much heat your body produces and how much heating you are getting from the sun on the sunny side.
As others have said, the big problem may be cooling due to water evaporating out of your skin. But, you could probably get a estimate for that too. Find out how much water you loose through your skin in a desert environment. Firgure out how much heat that carries away. There is the minimum amount of cooling you’ll get. Then take a WAG as to how many factors of X worse it would be in a vacuum. Then run the numbers with the other stuff above and see what the balance is. Hell, if you have access to a vacuum chamber and raw chicken with the skin still on
and a good scale you could get a decent estimate of the evaporation rate right there.
While your heart pushes blood out to arteries, gravity and atmospheric pressure is necessary for venous return. Blood would pool in the extremities. The brain would be starved in a matter of minutes.
Late to the party again :mad:
is this situation with or without astronaut diapers?
how about if you were hooked up to a cardiopulmonary bypass satellite?
And I think we can establish that a human space with merely a helmet to supply oxygen and pressurize the head, neck and throat area will surely succumb to the elements (or lack thereof, ha ha). But what is the method of death? Further reading on the subject leads me to believe that death without this helmet would occur fairly rapidly (within 2 minutes) but causes are the A) lack of oxygen getting to the brain and B) the heart no longer beating and providing a mechanism of creating pressure within the circulatory system to overcome the loss of pressure.
But what’s not clear is how the formation of water vapor within blood and tissue would be affected by the presence of the helmet, nor the supply of oxygen to the lungs that would theoretically keep the brain alive and blood flowing through the veins.
So, what’s the straight dope? How long will the presence of oxygen keep you alive? How long can you survive with dessicated skin? What are the exact likely causes of death?
Can the experience of Joe Kittinger be any guide?
Unfortunately I have been unable to find an exact timeline for the incident, so I’m not sure how much faster the effects would be if it was the whole body exposed, and not just the hand which was receiving normal everything from an otherwise okay body. Interesting to note though, at his highest the pressure was around that of the highest atmospheric pressure on Mars. I take it that means you wouldn’t be able to survive there without a suit either, but it’d be interesting to know what pure vacuum is like, because even 1/100atm is still far more significant than true space.
Curious timing. A few days ago I was watching a TV show where the protagonists went into orbit, and conducted an EVA ship-to-ship transfer without tethers. Most of the team were in proper space suits; one person wore nothing more than a breathing mask over his nose & mouth. (Given how well the show does real-world physics, I would have preferred that this character wore a full-face mask, protecting his eyes as well.) He showed no ill effects from internal overpressurization, solar radiation heating, self-radiation cooling, or indeed anything from exposure to vacuum. I can’t imagine how a normal person in the real world (not TV) would have survived.
Of course, the character in question was the Hulk, so “normal person” doesn’t apply.
The folks on the International Space Station are in a zero G environment, but they are not having circulatory problems… are they?
Whether you find an exact timeline or not isn’t relevant, as the situation you go on to describe didn’t happen anywhere along it.
That can’t be true, because your brain is not starved in minutes while hanging upside down, in which case gravity would be working against you.
I’m afraid, I’m not so sure about this. Maybe I’m missing something here, but I don’t think that when I’m standing gravity is pushing blood up my femoral artery back toward my heart.
And, I have to say I’m confused about how atmospheric pressure works to move blood, given that my feet and my chest are subjected to exactly the same atmospheric pressure.
Now, I’ll agree that having one part of the body (say, the right hand) unpressurized, while keeping the chest pressurized might lead to blood pooling in the affected body part, because of the difference in pressures, but that’s a separate question.
The situation described in the OP will cause almost immediate burst lungs. Although your skin is capable of holding 1 atmosphere pressure, your lungs are not. Your chest will expand enough for your lungs to over-inflate and rupture. It doesn’t take much differential pressure to cause this, and it is actually a major risk during diving if you ascend too quickly while holding your breath. Without something to provide pressure across the torso comparable to the pressure of the air you’re breathing in, you’ll die quite quickly.
Interesting articles, but unfortunately they discuss complete exposure to vacuum, not one where a human has a breathing apparatus equipped.
However, they do mention that a sudden loss of pressure on the body may lead to the bends (and death).