Help!! I'm drowning.....

[BP]

In space you have no hands? :shock:

Try to get into your vacc suit while using one hand to keep your nose
closed, and please make a video of the attempt for You Tube ... :lol:

:lol: No need - if you are holding your breath - you won't be worrying about that vacc suit! (You've just destroyed your lungs before you can really react, plus the rupturing ears have likely distracted you! Not to mention the adrenaline reaction has cut your time to remain conscious down to about 5 seconds for that excruciating pain if your heart hasn't already failed you!)

If you don't hold your breath (something an untrained person might be tempted to do) - then the few seconds of consciousness might be long enough for a trained person to don enough of a pressure suit (head gear) to complete the operation before feeling in the extremeties makes them unable to.

Consciousness time is generally estimated at 9 - 12 seconds - cut that in about half for explosive decompression (which might make that time meaningless) and excited responses.

 

[CosmicGamer]

I'm confused what scenario has a person going from a perfectly maintained environment to 100% vacuum instantaneously?

I know the term 'tossed out the airlock' is used but it is not like tossing someone over the side of a boat. The airlock takes time to cycle.

I would think that 'holding your breath' and donning a space suit would be done during some form of depressurization, or breakdown of environmental systems - a period of partial and decreasing environment perhaps, but vacuum?

Would a huge depressurization which sucks atmo out so fast you hit 100% vacuum in a few seconds be survived even by someone already in a vacc suit?

EDIT: perhaps serious damage to a vacc suit while in a vacuum could result in the situation where a person needs to 'holding their breath' and quickly locate and swap out whatever portion is damaged.

 

[rust]

As far as I know, this is about all we currently know for sure:

http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970603.html

 

[BP]

One would hope it is very rare - especially explosive deompression - though that is certainly an option in combat (and space accidents) - where depending on location (say a large hold versus a cabin) enough air may exist that several seconds go by and the effect of decompression doesn't lead to near immediate death (which is not a given, though the odds are not good).

(And again - holding ones breath to put on a suit is a big no-no under conditions of even relative rapid loss of pressure).

Aside from striking or being struck by something (like becoming a human hull patch ), there is no reason someone in a vacc suit should have any problem - the suit is designed to hold against pressure differentials (this already holds true in the real world, where rapid vaccum exposure is a reality aboard small spacecraft modules as well as very high altitude aircraft and balloons).

 

[GamerDude]

One of the things that keeps coming to my mind is an old encyclopedia entry about vaccum. It showed a test pilot in a pressurized suit (looked like a skin tight suit with lacing on the arms and legs to make it tight) holding a glass of water...

The water was boiling.

The article (and caption on the picture) said that at low pressure (I forget what the PSI was for this) water will boil at the same temperature that the human body maintains.

I'm gonna have to find that again.

 

[rust]

There is a nice "boy scout trick" to measure the height. Since the atmo-
spheric pressure decreases with height, and the boiling point of water de-
creases with atmospheric pressure, you only need to measure the tem-
perature of boiling water to find out how high in the mountains you are.

The rule of thumb is that 300 meters reduce the boiling point temperature
of clean water by 1 degree Celsius, so if the water boils at 92 degrees C
(and coffee and tea begin to taste strange), you are about 2,400 Meters
high.

 

[BP]

Yep - as I stated earlier

Space is cold because it is a near vacumm - which also means it doesn't conduct temperature well - so freezing is a lesser problem (though the lack of pressure will make water boil away - especially in the mouth )

I believe a high altitude pilot who was exposed stated he could feel the water in his mouth boil...

We are mostly water - but that water is retained by the skin and within cell walls - so the boiling away doesn't happen immediately (keep in mind the temp is also lowering - excepting radiation exposure, albiet more slowly due to lack of thermal medium to conduct it away).

The drastic effects of freezing and dropping pressure do occur - but one also has upto several minutes before death and irrepairable damage (but perhaps replaceable in high tech) occurs.