Could a kerbal breathe in a 3.5% methane atmosphere?

[alex_1313]

I want to add methane to Laythe's atmosphere, but i don't know if the kerbals could breathe in an enviroment with that much methane gas. Could they breathe?

Edited January 9, 2017 by alex_1313

[FlyingPete]

Well current evidence suggests that Laythe's atmo isn't entirely hospitable anyway- Kerbals keep their spacesuit helmets on. Perhaps the atmosphere contains some chemical which is toxic to Kerbals, or maybe it's almost breathable but not for long durations- much like climbers using supplementary oxygen on Everest.

No one can say for definite exactly how a Kerbal's biology works, so it's up to you to decide. I like the idea of them being able to partly photosythesise, hence the green skin.

[septemberWaves]

@FlyingPete I would imagine that kerbals keep their helmets on in Laythe's atmosphere not because of the atmosphere itself, but because of other environmental factors. Their suits aren't just space suits, they're environment suits, hence why they allow kerbals to survive in hostile environments like Eve's surface as well as in space. Laythe probably has hazards like dangerous temperatures, or radiation from Jool's magnetosphere, which would make it necessary for the kerbals to stay within their environment suits.

[Gaarst]

Kerbals don't breathe. If they did you wouldn't be able to leave them in a capsule for dozens of years. Add whatever you want to your atmosphere.

[FlyingPete]

2 minutes ago, eloquentJane said:

@FlyingPete I would imagine that kerbals keep their helmets on in Laythe's atmosphere not because of the atmosphere itself, but because of other environmental factors. Their suits aren't just space suits, they're environment suits, hence why they allow kerbals to survive in hostile environments like Eve's surface as well as in space. Laythe probably has hazards like dangerous temperatures, or radiation from Jool's magnetosphere, which would make it necessary for the kerbals to stay within their environment suits.

Exactly. I'd imagine a Kerbal could make a quick dash from the habitat module to the outhouse or a nearby craft without their helmet on, but wouldn't do well exposed permanently to the environment.

[EpicSpaceTroll139]

As far as I know you could have an atmosphere of 79% methane and 21% oxygen and a human would be fine. But that's just it, I know how it affects people, not Kerbals. I'd say it's entirely up to you whether you think Laythe should have a 3.5% methane.

[Tyko]

9 minutes ago, EpicSpaceTroll139 said:

As far as I know you could have an atmosphere of 79% methane and 21% oxygen and a human would be fine. But that's just it, I know how it affects people, not Kerbals. I'd say it's entirely up to you whether you think Laythe should have a 3.5% methane.

wouldn't a 79% methane / 21% Oxygen atmosphere explode when the first spark was introduced?

[EpicSpaceTroll139]

Just now, Tyko said:

wouldn't a 79% methane / 21% Oxygen atmosphere explode when the first spark was introduced?

I thought that at first too, but nope. The explosive limits of methane are 4.4% at the leanest and 17% at richest.

Actually, maybe that assumes regular air for the rest and not pure oxygen? I don't know I need to do some more research. I'll get back to you on that!

[Nathair]

5 minutes ago, Tyko said:

wouldn't a 79% methane / 21% Oxygen atmosphere explode when the first spark was introduced?

I don't know but in our atmosphere methane has an upper explosive limit of 15%... I think?

[Nathair]

30 minutes ago, Gaarst said:

Kerbals don't breathe. If they did you wouldn't be able to leave them in a capsule for dozens of years. Add whatever you want to your atmosphere.

I added some cannisters of TAC-LS to my Kerbals' atmosphere. (Apparently, Kerbals begin breathing and develop a severe methane allergy on exposure to TAC-LS.)

Edited January 9, 2017 by Nathair

[septemberWaves]

Explosive limits of methane probably vary depending on the temperature too. If it's colder, like Laythe probably is because of the distance from the sun, it would probably take more initial thermal energy to reach the required activation energy for combustion.

[Nathair]

8 minutes ago, eloquentJane said:

Explosive limits of methane probably vary depending on the temperature too. If it's colder, like Laythe probably is because of the distance from the sun, it would probably take more initial thermal energy to reach the required activation energy for combustion.

 

I found a flammability diagram for methane (on Wikipedia, of all places), temp not mentioned though.

[Hodari]

After being trapped in a small capsule with Jeb for any mission more than a couple hours long, they're probably breathing that much methane anyway...

[tomf]

Methane in an oxygen containing atmosphere is unstable over pretty short timescales so if you are going for realism it's pretty hard to imagine how it built up.

https://en.wikipedia.org/wiki/Atmospheric_methane#Troposphere

I think the creation of hydroxil is probably related to solar UV so there will be less of it around on Laythe, but still enough to require a very active methane source

[MinimalMinmus]

To me, as a similarity to terrian atmosphere, Laythe's could be 2% argon and 1% co2 ( hence the warm temperature) 

As of radiation, it is hard to say if Jool has a powerful van allen belt, as Jupiter has a huge one while Saturn has a small one. Besides, Laythe probably has a molten core, right?

[cantab]

Humans could breathe in an atmosphere with 3.5 % methane and otherwise suitable gases, presumably Kerbals would be fine. But as mentioned Laythe has something else poisonous. To me the obvious speculation is carbon dioxide, a few percent in the air is enough to stop us being able to diffuse it out of our lungs and therefore suffocates even with plenty of oxygen, and it would also contribute to Laythe's presumed strong greenhouse effect.

[Snark]

On 1/9/2017 at 0:47 PM, FlyingPete said:

Well current evidence suggests that Laythe's atmo isn't entirely hospitable anyway- Kerbals keep their spacesuit helmets on.

...but then again, they also keep their helmets on when they're on Kerbin, so it's hard to read much into that...

I've always assumed it's a caste / status thing.  "Hey, look at me, I'm an astronaut, not one of you landlubbers.  Check out the helmet!"  <preen>

[Carl]

On 09/01/2017 at 8:55 PM, eloquentJane said:

@FlyingPete I would imagine that kerbals keep their helmets on in Laythe's atmosphere not because of the atmosphere itself, but because of other environmental factors. Their suits aren't just space suits, they're environment suits, hence why they allow kerbals to survive in hostile environments like Eve's surface as well as in space. Laythe probably has hazards like dangerous temperatures, or radiation from Jool's magnetosphere, which would make it necessary for the kerbals to stay within their environment suits.

If Jool has major rad belts like jupiter a suit is not helping. Those things fry super-hardened electronics, never mind anything organic.

[septemberWaves]

39 minutes ago, Carl said:

If Jool has major rad belts like jupiter a suit is not helping. Those things fry super-hardened electronics, never mind anything organic.

Unless either the suit has super-dense plating, or it has a built-in personal magnetic field generator.

Edited January 12, 2017 by eloquentJane

[Carl]

If the plating is that dense the rocket would never fly, as for the generator, theoretically plausible, but not sure how practical, (minimum magnet size may be too large). A combined charge plus magnetic might work but in a spacesuit would be hellishly tricky.