Shirt sleeves on Duna?? Pack your coat and O2 tank!!!!

[StuntMax]

Anyone out there with some knowledge about when a pressure suit is needed? Would 40k require one? Or could you get away with maybe just a helmet

In WWII, crew in B26s and B29s flew at some 10-11000 m with no pressure suits (only oxygen mask... and a cozy warm sweater, of course), while retaining strenght and awareness reasonable enough to operate a war plane (including defending it with machine guns, that were hand operated), so i'd say that for a fit person, 12.000 m without a pressure suit may not be impossible.

Still, an oxygen mask would be mandatory.

[autumnalequinox]

To keep with the OP's question, and if I remember some of the details of the one-day Aviation Medicine lecture that I attended some thirty years ago, Earth's atmosphere contains 21% oxygen and the rest inert gasses. This means that if you climbed to an altitude corresponding to 21% sea level pressure, about 38,000 feet, breathing pure oxygen would give you the same mass (not volume) of oxygen as if you were breathing normal air at sea level. Above that the reduced oxygen pressure would require you to have a restraining garment to stop your chest expanding and the oxygen would need to be blown into you under some pressure from a tightly sealed face mask. Pressure breathing requires quite a bit of practice in a high altitude chamber as it is an abnormal way to breath. At about 60,000 feet you get into the blood-boiling area and need a full pressure suit. But yes, all other things being equal regarding temperature, radiation, etc. it should be possible to walk on Duna's surface with just an O2 tank. On the lower parts of the terrain anyhow.

i used to play with this full universe simulator for RPGs and it would generate random, plausible star systems with full suites of planets, moons, etc. 3d rendered to explore. I used to play with margin ability like crazy (you had data for atmo content, pressure, oceans, G, everything, and the program had thresholds for generation). This was always a big question for me that I never bothered calculating myself.. basically tweaking O2 percentages to inerts and atm and just seeing what is POSSIBLE for human survival.

So it's exponential then, 100% for 0.2 atm (of course with acclimation), So around 40 to 50% at 0.5 atm? So on?

So as earlier discussed, we will never really get EVA suits below 0.2 atm either for mobility.

This is all so fascinating I actually love atmospheric science I wish I had a spaceship with a warp drive so I could check out what is ACTUALLY out there that we may never see.

[RuBisCO]

Astronauts have operated at 5 psi (0.34 atm) for weeks back in the mercuary-gemini-apollo days. Spacesuits operate as low as 3.2 psi (0.21 atm) so it seems perfectly plausible that a kerbal breathing pure oxygen could live without a pressure suit at 0.2 atm, assuming they are as hardy or more then we are, and considering they don't seem to consume food, water or oxygen I'm beting they are tougher then us.

[GreeningGalaxy]

It's been suggested that kerbals are related to plants (green color, no food consumption), and as zoologically dubious as that is (very), we know that plants can survive very low pressures, at least according to Robert Zubrin. Who knows, though; maybe if kerbals photosynthesize, the CO2 atmosphere of Duna is completely breathable to them. Maybe overpopulation is why Kerbin's atmosphere is so oxygen-rich, so now they're exploiting that with jet engines to try to fly the last remaining kerbals somewhere with more CO2.

Yeah, doubt it.

Anyway...

Wikipedia/space.com mention that your blood won't ever boil, even in vacuum, because your blood vessels will be holding it at a higher pressure as it tries to expand. Of course, the bends can be an issue if you've been breathing nitrogen, but a little bit of decompression time and switching over to pure oxygen (which you'd obviously need to do at those pressures) would probably help with that. You'll probably want to bundle up a bit on Duna and wear goggles to keep your eyes from drying out, but as long as you're not exerting yourself too much and breathing pure oxygen, you, assuming you're a kerbal, might just be fine.

[Jett_Quasar]

I think Kerbals might be related to the Water Bear (Tardigrade) - they are the only animal that can survive in a vacuum as well as freezing temperatures and can go for up to a decade without food or water as well as having a high tolerance to radiation.

Check it out!

http://en.wikipedia.org/wiki/Water_bear

They sort of look like them too!!!

JR

Edited September 28, 2015 by Jolly_Roger

[Mrnoname]

I think Kerbals might be related to the Water Bear (Tardigrade) - they are the only animal that can survive in a vacuum as well as freezing temperatures and can go for up to a decade without food or water as well as having a high tolerance to radiation.

Check it out!

http://en.wikipedia.org/wiki/Water_bear

They sort of look like them too!!!

JR

There was a mission to expose them to vacuum, and it had an awesome abbreviation:

TARDIS

Tardigrades

In

Space

[monophonic]

There was a mission to expose them to vacuum, and it had an awesome abbreviation:

TARDIS

Tardigrades

In

Space

So that's where the Mystery Gooâ„¢ came from!

[Random Tank]

It's been suggested that kerbals are related to plants (green color, no food consumption)

Photosynthesis is not just sun = energy, plants aren't solar panels. Plants require light, water, Cardon Dioxide and Nitrates to survive.

Also plants, as well as pretty much anything that is alive, respire; this means that they also require oxygen and some form of glucose to survive, and produce carbon dioxide, water and energy for themselves. The rate of respiration is much lower than the rate of Photosynthesis, but photosynthesis only happens during the day (when light), whereas respiration happens all of the time. They produce more than enough oxygen for this, but they need the glucose, which requires a type of food.

Yes plants require considerably less food than we humans do, but don't say they don't need any! Kerbals may photosynthesise, but they need to keep up with the snack intake to get their nitrates!

[TimePeriod]

Photosynthesis is not just sun = energy, plants aren't solar panels. Plants require light, water, Cardon Dioxide and Nitrates to survive.

Also plants, as well as pretty much anything that is alive, respire; this means that they also require oxygen and some form of glucose to survive, and produce carbon dioxide, water and energy for themselves. The rate of respiration is much lower than the rate of Photosynthesis, but photosynthesis only happens during the day (when light), whereas respiration happens all of the time. They produce more than enough oxygen for this, but they need the glucose, which requires a type of food.

Yes plants require considerably less food than we humans do, but don't say they don't need any! Kerbals may photosynthesise, but they need to keep up with the snack intake to get their nitrates!

Ehh, not exactly.

Photosynthesise is the process where the plant splits a Co2 atom together with H20 to form sugar (most conmen is the Calvin cycle). As for the oxygen, its just released into the surroundings. The plant does not need it at this point.

Thus, 02 is a by-product we benefit from. In order to do this plants needs an array of nitrates such as; potassium, phosphor and nitrogen. Along with those are a larger group of micro-nutrients.

And arguably, nitrates are a lot easier to manufacture, move and store compared to organic snacks

[autumnalequinox]

It's been suggested that kerbals are related to plants (green color, no food consumption), and as zoologically dubious as that is (very), we know that plants can survive very low pressures, at least according to Robert Zubrin. Who knows, though; maybe if kerbals photosynthesize, the CO2 atmosphere of Duna is completely breathable to them. Maybe overpopulation is why Kerbin's atmosphere is so oxygen-rich, so now they're exploiting that with jet engines to try to fly the last remaining kerbals somewhere with more CO2.

Yeah, doubt it.

Anyway...

Wikipedia/space.com mention that your blood won't ever boil, even in vacuum, because your blood vessels will be holding it at a higher pressure as it tries to expand. Of course, the bends can be an issue if you've been breathing nitrogen, but a little bit of decompression time and switching over to pure oxygen (which you'd obviously need to do at those pressures) would probably help with that. You'll probably want to bundle up a bit on Duna and wear goggles to keep your eyes from drying out, but as long as you're not exerting yourself too much and breathing pure oxygen, you, assuming you're a kerbal, might just be fine.

I LOVE THIS.

Only I use TAC life support, sooo my Kerbals need all the goodies humans do, just less.

I also love that they may just be very large, highly evolved water bears. Which are the cutest micron-scale things there are. Wouldn't mind them on me (unlike fleas, lice, etc). Not at all.

"Who's a cute lil Tactopod?!? Yoouu are!!"

I'm glad I'm not the only one crazy enough to ponder Kerbals and their natures, evolution, and society as well. I even started my own little KSP RPG for when I get reeeally bored with career mode. I started developing a timeline and history. So this is GREAT stuff I may make some changes now.

They definately got lucky in the roll of the dice with their home system.

Imagine this.. if anyone is still reading..

At one point in history, for a brief time (in our Solar System), there may have been THREE habitable planets existing alongside each other. While I understand our knowledge of deep geological time is limited.. once, if things were right, there may have been oceans on Venus, Earth, and Mars simultaneously. Now we are talking about in the first billion or so years, but there was a window. So now imagine a different solar system, different percentages of raw materials and planets. So there is definately, somewhere, a system with terrestrial life and some habitable/marginal worlds located nearby as well. It's all about timing, and luck.

Can you imagine how our history would be if we got lucky like that? If we looked up into our night sky, and instead of a dead, scorched little gray ball we saw a sister planet (formed co-accretion style), and divined fortunes from it's clouds and shifting oceans. And then later.. we just had to GO there. A whole new world. Somewhere in our vast universe this has or is unfolding for some little green men or pink squiggies or giant water bears.

Ehh, not exactly.

Photosynthesise is the process where the plant splits a Co2 atom together with H20 to form sugar (most conmen is the Calvin cycle). As for the oxygen, its just released into the surroundings. The plant does not need it at this point.

Thus, 02 is a by-product we benefit from. In order to do this plants needs an array of nitrates such as; potassium, phosphor and nitrogen. Along with those are a larger group of micro-nutrients.

And arguably, nitrates are a lot easier to manufacture, move and store compared to organic snacks

Maybe all those "snacks" we see in IVA are compacted blue bars of plant food. Then add in some fuel cells for water (also hidden from view). Maybe some mice are hidden behind panels (in wheels of course) to replace plantlife in human closed-loop systems.

Edited August 27, 2014 by Specialist290
Merging sequential posts by same user