7 ms·

The Human Body in Space: Distinguishing Fact from Fiction (2013)

zeeshanqureshi 5y ago
Plus there could also be the psychological effects of possibly being isolated and confined in a small floating tin can.
- Akinato 5y ago
  IIRC Nasa put out a bunch of RFPs last year for studying, identifying, and alleviating that exact problem.
- seaorg 5y ago
  Imagine if they tried to cram a bunch of people in a literal metal tube with no windows and send them to the bottom of the ocean for months as a time. How could anyone be stupid enough to think that would work?
localhost 5y ago
I just finished listening to the Audible narration of the excellent Project Hail Mary [1] book by Andy Weir. It explores quite a few of these issues, including the cosmic radiation one. Highly recommended! [1] https://www.andyweirauthor.com/books/project-hail-mary https://www.andyweirauthor.com/books/project-hail-mary
geranim0 5y ago
In the movie Men Behind the Sun they show the japanse putting people in vacuum chambers and literally shit their guts
mattowen_uk 5y ago
Reading this, I learned that the 'Exposed To Space' stuff that happens in The Expanse (TV show - I've not read the books) is pretty much spot on.
Zimahl 5y ago
The Expanse handles this stuff much better than other shows, as has been noted many times. As entertaining as it is, For All Mankind gets things very wrong in a lot of cases and falls prey to a lot of the 'space tropes' that plague sci-fi. And I certainly don't expect hard sci-fi realism everywhere, but in something like For All Mankind, which is supposed to exist in an alternate timeline but be firmly planted in the real world, it's jarring. When it's in something like the movie Event Horizon I really don't care about realism.
- nojokes 5y ago
  In one episode Naomi inhales in just before exposure to the vacuum - it would have been fatal according to the article.
  - meristem 5y ago
    In the book she exhales: "She pushed her jaw forward in a yawn, opening her throat and her Eustachian tubes. Cyn yelped as she hit OPEN OUTER DOOR. Air tugged at her once, hard, as it evacuated. Adrenaline flooded her blood as she was assaulted invisibly on every square centimeter of flesh. The breath in her lungs rushed out of her, trying to pull her lungs along with it.[...] With her lungs empty, there was no reserve. She wasn’t holding her breath, surviving off the gas held inside her. Someone could hold their breath for a couple minutes. In the vacuum, she could make it maybe fifteen seconds unaided. Corey, James S.A.. Nemesis Games (The Expanse) (p. 425). Orbit. Kindle Edition.
    - nojokes 5y ago
      Nice to know that the author got it right in the book.
  - herewulf 5y ago
    If you're referring to the scene where she deliberately exits an airlock, then she actually exhaled whereas the other person with her did not and died. (Purposely being vague to avoiding spoiling anyone on this great series)
seaorg 5y ago
Make the transit ship spin. Surround the habitable parts with water and other materials. It’s so simple but nobody seems to be aware that these are solved problems.
- Supermancho 5y ago
  > It’s so simple but nobody seems to be aware that these are solved problems. It isnt reasonable to assume napkin solutions are "so simple" in practice or have not been considered. There are plenty of people smarter than either of us that look at these problems.
  - seaorg 5y ago
    The problem isn’t the smart people who look at these problems. It’s the collective behavior of the masses to have amnesia about basic physics.
    - defterGoose 5y ago
      Maybe the problem is people filling air with pseudo-scientific BS all the time, for instance, i dunno, Scientology?
      - seaorg 5y ago
        I’m not a Scientologist.
- jccalhoun 5y ago
  Lots of people have thought of similar things. I know I have read scifi which uses water for shielding but I can't think of a specific name. However, water isn't light. According to this post on stack exchange it would take something like 330,000kg of water to shield a crew. Getting that into orbit is a big task.
  - nojokes 5y ago
    Does something have better shielding mass ratio? But water itself can be more useful perhaps.
tgb 5y ago
> Because thermal radiation (the heat of the stove that you can feel from a distance, or from the Sun’s rays) becomes the predominant process for heat transfer, one might feel slightly warm if directly exposed to the Sun’s radiation, or slightly cool if shaded from sunlight, where the person’s own body will radiate away heat. Since the body also produces heat, would you even feel cool when shaded? If body heat generation outpaces radiation then I think you'd feel warm. Wikipedia puts the energy radiated out as about 2000kcals per day, or right around a human would produce from metabolism. So I guess it basically balances out. https://en.wikipedia.org/wiki/Black-body_radiation#Human-body_emission https://en.wikipedia.org/wiki/Black-body_radiation#Human-bod...
- mikewarot 5y ago
  Evaporation from your pores will still cool you a bit, as the water takes heat away with it when it leaves you.
causality0 5y ago
since two of the three methods of heat transfer (conduction and convection) This always drives me nuts. Convection is conduction, just in a fluid. Conduction and radiation are two entirely different physical processes.
- zizee 5y ago
  Doesn't convection also require movement of the fluid? Under gravity convection works by changes in density when the fluid is heated (e.g. hot air rises). This movement of the fluid provides an extra component beyond regular conduction. The movement of the fluid transfers heat away. In low g environments, convection due to density changes doesn't happen (hot air does not rise) which means heat pools around bodies at rest. Edit: after reading the article a bit, i see that you were quoting a section that ends with "...(conduction and convection) cannot occur without matter." Which does make the distinction the author was making a little more less useful. However lack of convection is an issue inside the space station where fans must be installed to keep air from pooling around heat sources like lights and human bodies.
- guntars 5y ago
  I think the distinguishing difference between conduction in a fluid and convection is that the fluid "leaves" and takes away the heat.
- lmilcin 5y ago
  Well, not exactly. Conduction means you touch something and that something slowly gets hotter and conducts heat away from your body. You can calculate how fast the energy is transferred based on properties of the material and geometry of objects and their interface. Convection means you touch something and that something is constantly being replaced. You can't use the formula for conduction here. In case of convection, the basic mechanism of energy being moved has nothing to do with conduction, rather with movement (replacement) of the material that takes away the heat. How is moving heat by moving the material and moving heat by letting it to dissipate through stationary material not two different processes?
- only_as_i_fall 5y ago
herewulf 5y ago
This should be tagged 2013. I came here just now thinking it was a new article. I actually found it by way of Google a couple months ago after watching a certain episode of The Expanse.
deleted 5y ago
[deleted]
sammalloy 5y ago
This article is from 2013, but since 2019, there's been active research in things like latent herpes reactivation, which could have implications for long duration spaceflight. https://www.frontiersin.org/articles/10.3389/fmicb.2019.00016/full https://www.frontiersin.org/articles/10.3389/fmicb.2019.0001...
Symmetry 5y ago
The big question for a Mars expedition is where between 1G and 0G Mars's .4G is for your body. We really need centrifuges in space to start studying this before it becomes something astronauts are depending on.

Plus there could also be the psychological effects of possibly being isolated and confined in a small floating tin can.

Akinato 5y ago
IIRC Nasa put out a bunch of RFPs last year for studying, identifying, and alleviating that exact problem.
seaorg 5y ago
Imagine if they tried to cram a bunch of people in a literal metal tube with no windows and send them to the bottom of the ocean for months as a time. How could anyone be stupid enough to think that would work?

I just finished listening to the Audible narration of the excellent Project Hail Mary [1] book by Andy Weir. It explores quite a few of these issues, including the cosmic radiation one. Highly recommended! [1] https://www.andyweirauthor.com/books/project-hail-mary https://www.andyweirauthor.com/books/project-hail-mary

geranim0 5y ago

In the movie Men Behind the Sun they show the japanse putting people in vacuum chambers and literally shit their guts

mattowen_uk 5y ago

Reading this, I learned that the 'Exposed To Space' stuff that happens in The Expanse (TV show - I've not read the books) is pretty much spot on.

Zimahl 5y ago

The Expanse handles this stuff much better than other shows, as has been noted many times. As entertaining as it is, For All Mankind gets things very wrong in a lot of cases and falls prey to a lot of the 'space tropes' that plague sci-fi. And I certainly don't expect hard sci-fi realism everywhere, but in something like For All Mankind, which is supposed to exist in an alternate timeline but be firmly planted in the real world, it's jarring. When it's in something like the movie Event Horizon I really don't care about realism.

nojokes 5y ago
In one episode Naomi inhales in just before exposure to the vacuum - it would have been fatal according to the article.
- meristem 5y ago
  In the book she exhales: "She pushed her jaw forward in a yawn, opening her throat and her Eustachian tubes. Cyn yelped as she hit OPEN OUTER DOOR. Air tugged at her once, hard, as it evacuated. Adrenaline flooded her blood as she was assaulted invisibly on every square centimeter of flesh. The breath in her lungs rushed out of her, trying to pull her lungs along with it.[...] With her lungs empty, there was no reserve. She wasn’t holding her breath, surviving off the gas held inside her. Someone could hold their breath for a couple minutes. In the vacuum, she could make it maybe fifteen seconds unaided. Corey, James S.A.. Nemesis Games (The Expanse) (p. 425). Orbit. Kindle Edition.
  - nojokes 5y ago
    Nice to know that the author got it right in the book.
- herewulf 5y ago
  If you're referring to the scene where she deliberately exits an airlock, then she actually exhaled whereas the other person with her did not and died. (Purposely being vague to avoiding spoiling anyone on this great series)

seaorg 5y ago

Make the transit ship spin. Surround the habitable parts with water and other materials. It’s so simple but nobody seems to be aware that these are solved problems.

Supermancho 5y ago
> It’s so simple but nobody seems to be aware that these are solved problems. It isnt reasonable to assume napkin solutions are "so simple" in practice or have not been considered. There are plenty of people smarter than either of us that look at these problems.
- seaorg 5y ago
  The problem isn’t the smart people who look at these problems. It’s the collective behavior of the masses to have amnesia about basic physics.
  - defterGoose 5y ago
    Maybe the problem is people filling air with pseudo-scientific BS all the time, for instance, i dunno, Scientology?
    - seaorg 5y ago
      I’m not a Scientologist.
jccalhoun 5y ago
Lots of people have thought of similar things. I know I have read scifi which uses water for shielding but I can't think of a specific name. However, water isn't light. According to this post on stack exchange it would take something like 330,000kg of water to shield a crew. Getting that into orbit is a big task.
- nojokes 5y ago
  Does something have better shielding mass ratio? But water itself can be more useful perhaps.

tgb 5y ago

> Because thermal radiation (the heat of the stove that you can feel from a distance, or from the Sun’s rays) becomes the predominant process for heat transfer, one might feel slightly warm if directly exposed to the Sun’s radiation, or slightly cool if shaded from sunlight, where the person’s own body will radiate away heat. Since the body also produces heat, would you even feel cool when shaded? If body heat generation outpaces radiation then I think you'd feel warm. Wikipedia puts the energy radiated out as about 2000kcals per day, or right around a human would produce from metabolism. So I guess it basically balances out. https://en.wikipedia.org/wiki/Black-body_radiation#Human-body_emission https://en.wikipedia.org/wiki/Black-body_radiation#Human-bod...

mikewarot 5y ago
Evaporation from your pores will still cool you a bit, as the water takes heat away with it when it leaves you.

causality0 5y ago

since two of the three methods of heat transfer (conduction and convection) This always drives me nuts. Convection is conduction, just in a fluid. Conduction and radiation are two entirely different physical processes.

zizee 5y ago
Doesn't convection also require movement of the fluid? Under gravity convection works by changes in density when the fluid is heated (e.g. hot air rises). This movement of the fluid provides an extra component beyond regular conduction. The movement of the fluid transfers heat away. In low g environments, convection due to density changes doesn't happen (hot air does not rise) which means heat pools around bodies at rest. Edit: after reading the article a bit, i see that you were quoting a section that ends with "...(conduction and convection) cannot occur without matter." Which does make the distinction the author was making a little more less useful. However lack of convection is an issue inside the space station where fans must be installed to keep air from pooling around heat sources like lights and human bodies.
guntars 5y ago
I think the distinguishing difference between conduction in a fluid and convection is that the fluid "leaves" and takes away the heat.
lmilcin 5y ago
Well, not exactly. Conduction means you touch something and that something slowly gets hotter and conducts heat away from your body. You can calculate how fast the energy is transferred based on properties of the material and geometry of objects and their interface. Convection means you touch something and that something is constantly being replaced. You can't use the formula for conduction here. In case of convection, the basic mechanism of energy being moved has nothing to do with conduction, rather with movement (replacement) of the material that takes away the heat. How is moving heat by moving the material and moving heat by letting it to dissipate through stationary material not two different processes?
only_as_i_fall 5y ago

herewulf 5y ago

This should be tagged 2013. I came here just now thinking it was a new article. I actually found it by way of Google a couple months ago after watching a certain episode of The Expanse.

deleted 5y ago

[deleted]

sammalloy 5y ago

This article is from 2013, but since 2019, there's been active research in things like latent herpes reactivation, which could have implications for long duration spaceflight. https://www.frontiersin.org/articles/10.3389/fmicb.2019.00016/full https://www.frontiersin.org/articles/10.3389/fmicb.2019.0001...

Symmetry 5y ago

The big question for a Mars expedition is where between 1G and 0G Mars's .4G is for your body. We really need centrifuges in space to start studying this before it becomes something astronauts are depending on.