Life support - Revision history

RichardWSmith: /* Energy storage */ Added link

2024-09-18T03:20:15Z

Energy storage: Added link

← Older revision		Revision as of 04:20, 18 September 2024
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	===Energy storage===		===Energy storage===
	Some of the oxygen producing [[greenhouse]]s may be lit at night, which requires [[energy storage\|stored electrical energy]] or ~~nuclear~~ power sources. However, it would probably be better to follow Mars' day and night cycle and reduce energy storage requirements. The stored energy quantity must be large enough to cover a few months of dust storms, again, unless nuclear reactors are used. [[wind turbine]]s may help to produce part of the needed energy during storms, but burning extra stored propellant may be more efficient. Food production and industrial production will also be reduced during sandstorms and any leftover solar power used for the habitats.		Some of the oxygen producing [[greenhouse]]s may be lit at night, which requires [[energy storage\|stored electrical energy]] or [[Nuclear power]] sources. However, it would probably be better to follow Mars' day and night cycle and reduce energy storage requirements. The stored energy quantity must be large enough to cover a few months of dust storms, again, unless nuclear reactors are used. [[wind turbine]]s may help to produce part of the needed energy during storms, but burning extra stored propellant may be more efficient. Food production and industrial production will also be reduced during sandstorms and any leftover solar power used for the habitats.

	===Water===		===Water===

Michel Lamontagne: /* Energy requirements */

2023-05-18T02:09:08Z

Energy requirements

← Older revision		Revision as of 03:09, 18 May 2023
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	As the water in the Martian environment is mostly frozen, thawing it into liquid water for settlement use and propellant production is a great heat sink for the settlement excess heat.		As the water in the Martian environment is mostly frozen, thawing it into liquid water for settlement use and propellant production is a great heat sink for the settlement excess heat.
	The power required for life support ~~has been~~ estimated ~~as somewhere between~~ 60 kW per person (Kalpana) ~~to 120 kW per person~~ (Mars one).		The power required for life support is often estimated at about 60 kW per person (Kalpana) and (Mars one).

	==See also==		==See also==

Michel Lamontagne: /* Energy requirements */

2023-05-18T02:06:13Z

Energy requirements

← Older revision		Revision as of 03:06, 18 May 2023
Line 143:		Line 143:

	As the water in the Martian environment is mostly frozen, thawing it into liquid water for settlement use and propellant production is a great heat sink for the settlement excess heat.		As the water in the Martian environment is mostly frozen, thawing it into liquid water for settlement use and propellant production is a great heat sink for the settlement excess heat.
			The power required for life support has been estimated as somewhere between 60 kW per person (Kalpana) to 120 kW per person (Mars one).

	==See also==		==See also==

Michel Lamontagne: /* Energy requirements */

2023-05-15T19:48:13Z

Energy requirements

← Older revision		Revision as of 20:48, 15 May 2023
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	Energy is required to run the life support system. The source of the energy is either the sun, though direct radiation of photoelectric systems, or nuclear fuel, using nuclear reactors, or a sum of both. The energy required to run the life support system when food production is included is considerably more (5 to 10 times more) than the energy required to produce propellant or to support industry.		Energy is required to run the life support system. The source of the energy is either the sun, though direct radiation of photoelectric systems, or nuclear fuel, using nuclear reactors, or a sum of both. The energy required to run the life support system when food production is included is considerably more (5 to 10 times more) than the energy required to produce propellant or to support industry.

	*The larger the life support system, the more stable it is.		The larger the life support system, the more stable it is. Humans operate at about 100W of power. This comes from food, that eventually comes from photosynthesis. Photosynthesis has an efficiency of about 3-4%, but most of the production from photosynthesis is used by the plant itself. About 0,5 to 1% of the energy from photosynthesis turns into food for humans. So the life support system of a settlement that includes food production will require a minimum of 100W/1% = 10 000W to 20 000W of average power per inhabitant.
	*Humans operate at about 100W of power. This comes from food, that eventually comes from photosynthesis. Photosynthesis has an efficiency of about 3-4%, but most of the production from photosynthesis is used by the plant itself. About 0,5 to 1% of the energy from photosynthesis turns into food for humans. So the life support system of a settlement that includes food production will require a minimum of 100W/1% = 10 000W to 20 000W of average power per inhabitant.		The other 99% of the energy absorbed by plants is turned into plant structure, and eventually biomass (about 1-2%) and heat (97-98%). The heat is mostly in the form of evaporated water, known at latent heat, and a hot air, called sensible heat. This heat needs to be removed from the settlement to avoid overheating.
	*The other 99% of the energy absorbed by plants is turned into plant structure, and eventually biomass (about 1-2%) and heat (97-98%). The heat is mostly in the form of evaporated water, known at latent heat, and a hot air, called sensible heat. This heat needs to be removed from the settlement to avoid overheating.
	*The heat loss rate of the settlement habitat depends on its construction. If it is well insulated, it will lose little heat, and will need to be cooled using active mechanical systems. If it is poorly insulated it could cool itself by radiation and convection to the Martian environment. However, if the heating ever failed the settlement might freeze rapidly.		The heat loss rate of the settlement habitat depends on its construction. If it is well insulated, it will lose little heat, and will need to be cooled using active mechanical systems. If it is poorly insulated it could cool itself by radiation and convection to the Martian environment. However, if the heating ever failed the settlement might freeze rapidly.
	[[File:Colony thermal systems.png\|thumb\|600x600px\|Thermal systems for the settlement.]]		[[File:Colony thermal systems.png\|thumb\|600x600px\|Thermal systems for the settlement.]]
	*As it is easier to stop food production in case of a loss of power, in fact, it pretty much stops itself, it makes more sense to insulate the settlement that to try to have it in thermal equilibrium.
	*As the water in the Martian environment is mostly frozen, thawing it into liquid water for settlement use and propellant production is a great heat sink for the settlement excess heat.		As it is easier to stop food production in case of a loss of power, in fact, it pretty much stops itself, it makes more sense to insulate the settlement that to try to have it in thermal equilibrium.

			As the water in the Martian environment is mostly frozen, thawing it into liquid water for settlement use and propellant production is a great heat sink for the settlement excess heat.

	==See also==		==See also==

Michel Lamontagne: /* Energy requirements */

2023-05-15T19:47:28Z

Energy requirements

← Older revision		Revision as of 20:47, 15 May 2023
Line 134:		Line 134:
	Energy is required to run the life support system. The source of the energy is either the sun, though direct radiation of photoelectric systems, or nuclear fuel, using nuclear reactors, or a sum of both. The energy required to run the life support system when food production is included is considerably more (5 to 10 times more) than the energy required to produce propellant or to support industry.		Energy is required to run the life support system. The source of the energy is either the sun, though direct radiation of photoelectric systems, or nuclear fuel, using nuclear reactors, or a sum of both. The energy required to run the life support system when food production is included is considerably more (5 to 10 times more) than the energy required to produce propellant or to support industry.

	The larger the life support system, the more stable it is.		*The larger the life support system, the more stable it is.
			*Humans operate at about 100W of power. This comes from food, that eventually comes from photosynthesis. Photosynthesis has an efficiency of about 3-4%, but most of the production from photosynthesis is used by the plant itself. About 0,5 to 1% of the energy from photosynthesis turns into food for humans. So the life support system of a settlement that includes food production will require a minimum of 100W/1% = 10 000W to 20 000W of average power per inhabitant.
	Humans operate at about 100W of power. This comes from food, that eventually comes from photosynthesis. Photosynthesis has an efficiency of about 3-4%, but most of the production from photosynthesis is used by the plant itself. About 0,5 to 1% of the energy from photosynthesis turns into food for humans. So the life support system of a settlement that includes food production will require a minimum of 100W/1% = 10 000W to 20 000W of average power per inhabitant.		*The other 99% of the energy absorbed by plants is turned into plant structure, and eventually biomass (about 1-2%) and heat (97-98%). The heat is mostly in the form of evaporated water, known at latent heat, and a hot air, called sensible heat. This heat needs to be removed from the settlement to avoid overheating.
			*The heat loss rate of the settlement habitat depends on its construction. If it is well insulated, it will lose little heat, and will need to be cooled using active mechanical systems. If it is poorly insulated it could cool itself by radiation and convection to the Martian environment. However, if the heating ever failed the settlement might freeze rapidly.
	The other 99% of the energy absorbed by plants is turned into plant structure, and eventually biomass (about 1-2%) and heat (97-98%). The heat is mostly in the form of evaporated water, known at latent heat, and a hot air, called sensible heat. This heat needs to be removed from the settlement to avoid overheating.

	The heat loss rate of the settlement habitat depends on its construction. If it is well insulated, it will lose little heat, and will need to be cooled using active mechanical systems. If it is poorly insulated it could cool itself by radiation and convection to the Martian environment. However, if the heating ever failed the settlement might freeze rapidly.
	[[File:Colony thermal systems.png\|thumb\|600x600px\|Thermal systems for the settlement.]]		[[File:Colony thermal systems.png\|thumb\|600x600px\|Thermal systems for the settlement.]]
			*As it is easier to stop food production in case of a loss of power, in fact, it pretty much stops itself, it makes more sense to insulate the settlement that to try to have it in thermal equilibrium.
	As it is easier to stop food production in case of a loss of power, in fact, it pretty much stops itself, it makes more sense to insulate the settlement that to try to have it in thermal equilibrium.		*As the water in the Martian environment is mostly frozen, thawing it into liquid water for settlement use and propellant production is a great heat sink for the settlement excess heat.

	As the water in the Martian environment is mostly frozen, thawing it into liquid water for settlement use and propellant production is a great heat sink for the settlement excess heat.

	==See also==		==See also==

Michel Lamontagne: /* Energy requirements */

2023-05-15T19:46:51Z

Energy requirements

← Older revision		Revision as of 20:46, 15 May 2023
Line 132:		Line 132:
	==Energy requirements==		==Energy requirements==
	[[File:Colony power systems (3).png\|thumb\|600x600px\|Power systems for the settlement. Mature large settlement with food and propellant production.]]		[[File:Colony power systems (3).png\|thumb\|600x600px\|Power systems for the settlement. Mature large settlement with food and propellant production.]]
	Energy is required to run the life support system. The source of the energy is either the sun, though direct radiation of photoelectric systems, or nuclear fuel, using nuclear reactors. The energy required to run the life support system when food production is included, is considerably more than the energy required to produce propellant or to support industry.		Energy is required to run the life support system. The source of the energy is either the sun, though direct radiation of photoelectric systems, or nuclear fuel, using nuclear reactors, or a sum of both. The energy required to run the life support system when food production is included is considerably more (5 to 10 times more) than the energy required to produce propellant or to support industry.

	The larger the life support system, the more stable it is.		The larger the life support system, the more stable it is.

	Humans operate at about 100W of power. This comes from food, that eventually comes from photosynthesis. Photosynthesis has an efficiency of about 3-4%, but most of the production from photosynthesis is used by the plant itself. About 0,5 to 1% of the energy from photosynthesis turns into food for humans~~, so~~ the life support system of a settlement that includes food production will require ~~about~~ 100W/1% = 10 000W to 20 000W of average ~~solar~~ power per inhabitant.		Humans operate at about 100W of power. This comes from food, that eventually comes from photosynthesis. Photosynthesis has an efficiency of about 3-4%, but most of the production from photosynthesis is used by the plant itself. About 0,5 to 1% of the energy from photosynthesis turns into food for humans. So the life support system of a settlement that includes food production will require a minimum of 100W/1% = 10 000W to 20 000W of average power per inhabitant.

	The other 99% is turned into plant and eventually biomass (about 1-2%), and ~~into~~ heat (97-98%), in the form of evaporated water, known at latent heat, and a hot air, called sensible heat. This heat needs to be removed from the settlement to avoid overheating.		The other 99% of the energy absorbed by plants is turned into plant structure, and eventually biomass (about 1-2%) and heat (97-98%). The heat is mostly in the form of evaporated water, known at latent heat, and a hot air, called sensible heat. This heat needs to be removed from the settlement to avoid overheating.

	The heat loss rate of the settlement habitat depends on its construction. If it is well insulated, it will lose little heat, and will need to be cooled using active mechanical systems. If it is poorly insulated it could cool itself by radiation and convection to the Martian environment. However, if the heating ever failed the settlement might freeze rapidly.		The heat loss rate of the settlement habitat depends on its construction. If it is well insulated, it will lose little heat, and will need to be cooled using active mechanical systems. If it is poorly insulated it could cool itself by radiation and convection to the Martian environment. However, if the heating ever failed the settlement might freeze rapidly.

Michel Lamontagne: /* Grey water treatment */

2021-07-06T12:51:59Z

Grey water treatment

← Older revision		Revision as of 13:51, 6 July 2021
Line 80:		Line 80:

	==='''Grey water treatment'''===		==='''Grey water treatment'''===
	Water used for washing, showers and purposes other than human wastes must be recycled. This will be at least equal to the potable water requirements, but may eventually be significantly higher.		Water used for washing, showers and purposes other than human wastes must be recycled. This will be at least equal to the potable water requirements, but may eventually be significantly higher.

			=== Atmospheric water ===
			Water from sweat and respiration is also recycled, at a rate off about 1 kg per person. Water is removed from air by condensation or desiccation with regenerative media. Any plants in the habitat will add significantly to the atmospheric water load through [[Evapotranspiration\|evapotranspiration.]]

	==='''Air recycling'''===		==='''Air recycling'''===

Michel Lamontagne: /* Buffering the gases */

2021-07-06T00:49:56Z

Buffering the gases

← Older revision		Revision as of 01:49, 6 July 2021
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	Plant life produces excess oxygen for a life support system that only includes humans. The Mars One life support system design was criticized for producing too much oxygen, leading eventually to oxygen poisoning of the colonists<ref>Do, Sydney, Koki Ho, Samuel Steven Schreiner, Andrew Charles Owens, and Olivier L. de Weck. "An independent assessment of the technical feasibility of the mars one mission plan." (2014).</ref>. It will be possible to remove excess oxygen using separation methods, but this reduces the possibility of an entirely 'natural' life support system, at least in the early years of the settlement.		Plant life produces excess oxygen for a life support system that only includes humans. The Mars One life support system design was criticized for producing too much oxygen, leading eventually to oxygen poisoning of the colonists<ref>Do, Sydney, Koki Ho, Samuel Steven Schreiner, Andrew Charles Owens, and Olivier L. de Weck. "An independent assessment of the technical feasibility of the mars one mission plan." (2014).</ref>. It will be possible to remove excess oxygen using separation methods, but this reduces the possibility of an entirely 'natural' life support system, at least in the early years of the settlement.

	An atmosphere like Earth's will require a lot of nitrogen. One with of 0.2 bar of oxygen, and 0.2 bar of nitrogen, (plus a trace of neon & argon), might be a reasonable compromise for plant health, safety, and expense.		An atmosphere like Earth's will require a lot of nitrogen. One with of 0.2 bar of oxygen, and 0.2 bar of nitrogen, (plus a trace of neon & argon), might be a reasonable compromise for plant health, safety, and expense. However the nitrogen cycle of plants might be affected, so further study is needed.

	===Energy storage===		===Energy storage===
	~~Parts~~ of the oxygen producing [[greenhouse]]s may be lit at night, which requires [[energy storage\|stored electrical energy]] or nuclear power sources. However, it would probably be better to follow ~~Earth~~ day and night cycle and reduce energy storage requirements. The stored energy quantity must be large enough to cover a few months of dust storms, again, unless nuclear reactors are used. [[wind turbine]]s may help to produce part of the needed energy during storms, but burning extra stored propellant may be more efficient. Food production and industrial production will also be reduced during sandstorms and any leftover solar power used for the habitats.		Some of the oxygen producing [[greenhouse]]s may be lit at night, which requires [[energy storage\|stored electrical energy]] or nuclear power sources. However, it would probably be better to follow Mars' day and night cycle and reduce energy storage requirements. The stored energy quantity must be large enough to cover a few months of dust storms, again, unless nuclear reactors are used. [[wind turbine]]s may help to produce part of the needed energy during storms, but burning extra stored propellant may be more efficient. Food production and industrial production will also be reduced during sandstorms and any leftover solar power used for the habitats.

	===Water===		===Water===

Michel Lamontagne: /* Buffering the gases */

2021-07-06T00:44:56Z

Buffering the gases

← Older revision		Revision as of 01:44, 6 July 2021
Line 109:		Line 109:
	===Buffering the gases===		===Buffering the gases===

	Humans breathe oxygen, but an atmosphere of pure oxygen at 1 bar pressure would be toxic and explosively flammable. We require buffer gases to reduce the partial pressure of oxygen. On Earth the primary buffer gas is nitrogen. The Martian atmosphere contains the ~~Nobel~~ gases neon and argon which also can be used as buffer gases.		Humans breathe oxygen, but an atmosphere of pure oxygen at 1 bar pressure would be toxic and explosively flammable. We require buffer gases to reduce the partial pressure of oxygen. On Earth the primary buffer gas is nitrogen. The Martian atmosphere contains the noble gases [[neon]] and [[argon]] which also can be used as buffer gases.

	~~Big~~ tanks of [[water]] may be used to buffer some amount of oxygen as well as CO<sub>2</sub>, since those gases are soluble in water according to [https://en.wikipedia.org/wiki/Henry's_law Henry's law]. A good side effect is the heat capacity of the water, helping to keep a comfortable temperature in the settlement. Oxygen produced for propellant purposes will need to be stored, and this storage can be used to buffer the oxygen. CO2 can be extracted from the atmosphere and the carbon stored in methane as CH4. Artificial life support systems can be used in parallel to help regulate the overall system.		Large tanks of [[water]] may be used to buffer some amount of oxygen as well as CO<sub>2</sub>, since those gases are soluble in water according to [https://en.wikipedia.org/wiki/Henry's_law Henry's law]. A good side effect is the heat capacity of the water, helping to keep a comfortable temperature in the settlement. Oxygen produced for propellant purposes will need to be stored, and this storage can be used to buffer some of the oxygen. CO2 can be extracted from the atmosphere and the carbon stored in methane as CH4. Artificial life support systems can be used in parallel to help regulate the overall system.

	Plant life produces excess oxygen for a life support system that only includes humans. The Mars One life support system design was criticized for producing too much oxygen, leading eventually to oxygen poisoning of the colonists<ref>Do, Sydney, Koki Ho, Samuel Steven Schreiner, Andrew Charles Owens, and Olivier L. de Weck. "An independent assessment of the technical feasibility of the mars one mission plan." (2014).</ref>. It will be possible to remove excess oxygen using separation methods, but this reduces the possibility of an entirely 'natural' life support system, at least in the early years of the settlement.		Plant life produces excess oxygen for a life support system that only includes humans. The Mars One life support system design was criticized for producing too much oxygen, leading eventually to oxygen poisoning of the colonists<ref>Do, Sydney, Koki Ho, Samuel Steven Schreiner, Andrew Charles Owens, and Olivier L. de Weck. "An independent assessment of the technical feasibility of the mars one mission plan." (2014).</ref>. It will be possible to remove excess oxygen using separation methods, but this reduces the possibility of an entirely 'natural' life support system, at least in the early years of the settlement.
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	Respiration from humans and evapotranspiration from plants will load the atmosphere of a settlement with humidity. This water needs to be removed by condensation, or the humidity will become too high and the plants will no longer function, and the humans will be very uncomfortable. Desiccant systems with regeneration or cooling systems with condensation are two methods for dehumidifying the air in the settlement. The cold outside the colony can be used at a handy heat sink for dehumidification as well.		Respiration from humans and evapotranspiration from plants will load the atmosphere of a settlement with humidity. This water needs to be removed by condensation, or the humidity will become too high and the plants will no longer function, and the humans will be very uncomfortable. Desiccant systems with regeneration or cooling systems with condensation are two methods for dehumidifying the air in the settlement. The cold outside the colony can be used at a handy heat sink for dehumidification as well.

	Plants require large amounts of water to function correctly. In [[Greenhouse\|greenhouses]], water irrigation requirements have a typical value of 10 to 16 l/m2 per day<ref>https://ag.umass.edu/greenhouse-floriculture/fact-sheets/sizing-greenhouse-water-system</ref>. So plants to feed one person require up to 16 l/m2 x 365 m2/person = 5 840 liters per day. This water must be recycled and is more than 1000 times the water required for direct consumption.		Plants require large amounts of water to function correctly. In [[Greenhouse\|greenhouses]], water irrigation requirements have a typical value of 10 to 16 l/m2 per day<ref>https://ag.umass.edu/greenhouse-floriculture/fact-sheets/sizing-greenhouse-water-system</ref>. So plants to feed one person require up to 16 l/m2 x 365 m2/person = 5 840 liters per day. This water must be recycled and is more than 1000 times the water required for direct human consumption.

	==Energy requirements==		==Energy requirements==

RichardWSmith: /* Buffering the gases */ Added links and more information on buffering the atmosphere with lower amounts of nitrogen. Also described what a buffer gas IS.

2021-07-05T23:57:42Z

Buffering the gases: Added links and more information on buffering the atmosphere with lower amounts of nitrogen. Also described what a buffer gas IS.

← Older revision		Revision as of 00:57, 6 July 2021
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	==='''CO<sub>2</sub> concentrations'''===		==='''CO<sub>2</sub> concentrations'''===
	~~CO<sub>2</sub>~~ concentrations are normally 400 PPM, or 0,04% of the atmosphere. Large variations are possible, but the maximum comfort zone is between 600 and 1000 ppm. Adverse health effect appear at 2500-5000 ppm. At 50 000 ppm and more severe symptoms occur and eventually death.		[[Carbon dioxide]] concentrations are normally 400 PPM, or 0,04% of the atmosphere. Large variations are possible, but the maximum comfort zone is between 600 and 1000 ppm. Adverse health effect appear at 2500-5000 ppm. At 50 000 ppm and more severe symptoms occur and eventually death.

	This sets the limits for the CO<sub>2</sub> amount in the settlement atmosphere. For a 1000 person settlement, settlers produce about 1 ton of CO<sub>2</sub> per day. If there is no CO<sub>2</sub> recycling, the concentration will go up fairly slowly. Allocating 100 m3 per settler, the volume would be 1 million m<sup>3</sup> and hold about 400m<sup>3</sup> of CO<sub>2</sub>, or 560kg. At one tonnes per day, it would take about one day to move up to 1200 ppm and about five days to reach the more dangerous levels of 5000+ ppm.		This sets the limits for the CO<sub>2</sub> amount in the settlement atmosphere. For a 1000 person settlement, settlers produce about 1 ton of CO<sub>2</sub> per day. If there is no CO<sub>2</sub> recycling, the concentration will go up fairly slowly. Allocating 100 m3 per settler, the volume would be 1 million m<sup>3</sup> and hold about 400m<sup>3</sup> of CO<sub>2</sub>, or 560kg. At one tonnes per day, it would take about one day to move up to 1200 ppm and about five days to reach the more dangerous levels of 5000+ ppm.

	===Nitrogen supply===		===Nitrogen supply===
	Nitrogen is often seen as a relatively neutral buffer gas. However, there is a nitrogen cycle in a natural life support system required for plant life. Nitrogen is relatively rare on Mars, so nitrogen losses should be kept to a minimum.		[[Nitrogen]] is often seen as a relatively neutral buffer gas. However, there is a nitrogen cycle in a natural life support system required for plant life. Nitrogen is relatively rare on Mars, so nitrogen losses should be kept to a minimum. (However, some theorize that large nitrate deposits will exist on Mars, see [[Atmospheric loss]].)
	==Artificial life support systems==		==Artificial life support systems==
	[[File:Colony life systems.png\|alt=\|thumb\|600x600px\|Artificial, open loop Life support system. Requirements per person.]]		[[File:Colony life systems.png\|alt=\|thumb\|600x600px\|Artificial, open loop Life support system. Requirements per person.]]
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	===Buffering the gases===		===Buffering the gases===

			Humans breathe oxygen, but an atmosphere of pure oxygen at 1 bar pressure would be toxic and explosively flammable. We require buffer gases to reduce the partial pressure of oxygen. On Earth the primary buffer gas is nitrogen. The Martian atmosphere contains the Nobel gases neon and argon which also can be used as buffer gases.

	Big tanks of [[water]] may be used to buffer some amount of oxygen as well as CO<sub>2</sub>, since those gases are soluble in water according to [https://en.wikipedia.org/wiki/Henry's_law Henry's law]. A good side effect is the heat capacity of the water, helping to keep a comfortable temperature in the settlement. Oxygen produced for propellant purposes will need to be stored, and this storage can be used to buffer the oxygen. CO2 can be extracted from the atmosphere and the carbon stored in methane as CH4. Artificial life support systems can be used in parallel to help regulate the overall system.		Big tanks of [[water]] may be used to buffer some amount of oxygen as well as CO<sub>2</sub>, since those gases are soluble in water according to [https://en.wikipedia.org/wiki/Henry's_law Henry's law]. A good side effect is the heat capacity of the water, helping to keep a comfortable temperature in the settlement. Oxygen produced for propellant purposes will need to be stored, and this storage can be used to buffer the oxygen. CO2 can be extracted from the atmosphere and the carbon stored in methane as CH4. Artificial life support systems can be used in parallel to help regulate the overall system.

	Plant life produces excess oxygen for a life support system that only includes humans. The Mars One life support system design was criticized for producing too much oxygen, leading eventually to oxygen poisoning of the colonists<ref>Do, Sydney, Koki Ho, Samuel Steven Schreiner, Andrew Charles Owens, and Olivier L. de Weck. "An independent assessment of the technical feasibility of the mars one mission plan." (2014).</ref>. It will be possible to remove excess oxygen using separation methods, but this reduces the possibility of an entirely 'natural' life support system, at least in the early years of the settlement.		Plant life produces excess oxygen for a life support system that only includes humans. The Mars One life support system design was criticized for producing too much oxygen, leading eventually to oxygen poisoning of the colonists<ref>Do, Sydney, Koki Ho, Samuel Steven Schreiner, Andrew Charles Owens, and Olivier L. de Weck. "An independent assessment of the technical feasibility of the mars one mission plan." (2014).</ref>. It will be possible to remove excess oxygen using separation methods, but this reduces the possibility of an entirely 'natural' life support system, at least in the early years of the settlement.

			An atmosphere like Earth's will require a lot of nitrogen. One with of 0.2 bar of oxygen, and 0.2 bar of nitrogen, (plus a trace of neon & argon), might be a reasonable compromise for plant health, safety, and expense.

	===Energy storage===		===Energy storage===