seriously though, any serious attempt to live on mars would obviously use electrolysis of water to produce oxygen on mars, because to do so you only need electricity and water.
you need about 1 kg of water and 1 kWh of electricity per person per day to produce enough oxygen.
source: my own math
you can calculate this if you consider that people need about 8 MJ of energy a day, and bread has around 15 MJ of energy per kg, so people need around 0.5 kg of bread a day, that’s approx. 0.5 kg of carbon atoms. since each carbon atom combines with 2 oxygen atoms, that makes twice as many oxygen atoms as carbon atoms. assuming they are the same mass (which they almost are), that’s about 1 kg of oxygen a day. 1 kg of water contains about 1 kg of oxygen atoms.
and then you could produce O2, which you’re gonna breathe in, and you’re gonna exhale CO2, which you then need to remove from the atmosphere, which you can do with a CO2 scrubber
1kg of oxygen is a good estimate, humand need 0.5-1kg per day.
Astronaut calorie budges is a bit higher than average, as would be for labouring humans. About 3000kcal, or 12 MJ.
I think more important than the raw energy and oxygen is sourcing the water, cleaning the water, producing the energy to electrolyse and heat, and maintaining the equipment necessary to do so. And that’s assuming all food is shipped in.
I think more important than the raw energy and oxygen is sourcing the water
yeah i actually believe that too. i calculated somewhere that it takes around 10 kWh per kg of water extracted from the soil, assuming you follow this process and assuming a 30% water content in the regolith.
So yes, total energy consumption is a bit higher, but it’s only a rough estimate to give you an idea of the order of magnitude that we’re talking about.
seriously though, any serious attempt to live on mars would obviously use electrolysis of water to produce oxygen on mars, because to do so you only need electricity and water.
you need about 1 kg of water and 1 kWh of electricity per person per day to produce enough oxygen.
source: my own math
you can calculate this if you consider that people need about 8 MJ of energy a day, and bread has around 15 MJ of energy per kg, so people need around 0.5 kg of bread a day, that’s approx. 0.5 kg of carbon atoms. since each carbon atom combines with 2 oxygen atoms, that makes twice as many oxygen atoms as carbon atoms. assuming they are the same mass (which they almost are), that’s about 1 kg of oxygen a day. 1 kg of water contains about 1 kg of oxygen atoms.
about how much energy you need: you can calculate this with Standard enthalpy of formation of water. (given in the sidebar here)
I’m just too lazy to do this rn, so you’re gonna have to believe me.
and about how to get electricity, see my post here
and about how to get water, see my post here and this article.
and then you could produce O2, which you’re gonna breathe in, and you’re gonna exhale CO2, which you then need to remove from the atmosphere, which you can do with a CO2 scrubber
1kg of oxygen is a good estimate, humand need 0.5-1kg per day.
Astronaut calorie budges is a bit higher than average, as would be for labouring humans. About 3000kcal, or 12 MJ.
I think more important than the raw energy and oxygen is sourcing the water, cleaning the water, producing the energy to electrolyse and heat, and maintaining the equipment necessary to do so. And that’s assuming all food is shipped in.
yeah i actually believe that too. i calculated somewhere that it takes around 10 kWh per kg of water extracted from the soil, assuming you follow this process and assuming a 30% water content in the regolith.
So yes, total energy consumption is a bit higher, but it’s only a rough estimate to give you an idea of the order of magnitude that we’re talking about.
Also i wrote about food production here.