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I took a tour of Mesa Verde Ruins years ago and the tour guide explained how the inhabitants farmed and on what crops they subsisted on as well as other interesting things. One thing that I found especially interesting is the story of how he and a friend decided to try to live only upon what they grew on their land. Each of the men had five acres and a water well and each worked together and rotated crops etc. Sadly, they both had to give up as they could not grow enough food to live upon. He made a point that many people had to grow different things and then share back and forth etc. within the Mesa Verde Settlement. If ten acres of prime land and endless water with clean air produces such dismal results how much harder will it be to grow enough food on Mars. I would guess that to just be able to plant and harvest on five acres on Mars one would need a massive amount of infrastructure in place first. The infrastructure I suppose could happen but not with just a handful of scientists or astronauts. Masons, Electricians, Plumbers, AC, Steel workers, Heavy Equipment Operators, and much more would need to make the trip as well. Supplies and equipment would have to be in place and a more sustainable and safe habitat would have to be constructed within 40-50 days before food shortages or air problems began. Reserves of air, water, food, first aid, and more would need to be stock piled and in quantities well above estimates in case something goes wrong for each building phase etc. and for all contractors, astronauts, scientists, and so on. Cost to build a decent sustainable, safe, and large enough habitat that would allow for a proper foothold (within the next 50-60 years), probably at least 4-6 billion here on earth, but on Mars I would estimate 5 trillion on up. If a small manned mission that is basically a short stay and minimal exploration, costs 4-5 hundred million it's easy to extrapolate out from there. Small amounts of work done by small amounts of people done over long periods of time on one seriously inhospitable planet probably doesn't equate to very good productivity/results and I would think that the short visit/stay cycle would never be overcome. Essentially stuck starving on five acres.
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This is a fascinating area which I am sure could hold some lessons for Mars. I wonder whether those two guys were (a) experienced farmers (b) working hard at it and (c) farming in the right area. From the NPS site:
"The mesa top is blanketed by a red soil called loess
. Loess is a
deposit of very fine silt, which is transported by the wind from
dry regions. The loess in Mesa Verde has been blown in by south
-
westerly wind for the past one million years. The soil is very rich
and holds moisture, thus is a perfect medium for agriculture. The
large pinyon and juniper trees here are evidence of the fertility
of this soil. The Ancestral Puebloans recognized it as ideal farm
-
land and planted on the mesa tops where the loess is 3 to 30 feet
deep. When the people cut down trees for building and firewood,
this left the bare loess vulnerable to erosion. Where the loess has
eroded, it is very difficult to farm the mesa."
They might have been farming somewhere where the loess had been eroded.
I took a tour of Mesa Verde Ruins years ago and the tour guide explained how the inhabitants farmed and on what crops they subsisted on as well as other interesting things. One thing that I found especially interesting is the story of how he and a friend decided to try to live only upon what they grew on their land. Each of the men had five acres and a water well and each worked together and rotated crops etc. Sadly, they both had to give up as they could not grow enough food to live upon. He made a point that many people had to grow different things and then share back and forth etc. within the Mesa Verde Settlement. If ten acres of prime land and endless water with clean air produces such dismal results how much harder will it be to grow enough food on Mars. I would guess that to just be able to plant and harvest on five acres on Mars one would need a massive amount of infrastructure in place first. The infrastructure I suppose could happen but not with just a handful of scientists or astronauts. Masons, Electricians, Plumbers, AC, Steel workers, Heavy Equipment Operators, and much more would need to make the trip as well. Supplies and equipment would have to be in place and a more sustainable and safe habitat would have to be constructed within 40-50 days before food shortages or air problems began. Reserves of air, water, food, first aid, and more would need to be stock piled and in quantities well above estimates in case something goes wrong for each building phase etc. and for all contractors, astronauts, scientists, and so on. Cost to build a decent sustainable, safe, and large enough habitat that would allow for a proper foothold (within the next 50-60 years), probably at least 4-6 billion here on earth, but on Mars I would estimate 5 trillion on up. If a small manned mission that is basically a short stay and minimal exploration, costs 4-5 hundred million it's easy to extrapolate out from there. Small amounts of work done by small amounts of people done over long periods of time on one seriously inhospitable planet probably doesn't equate to very good productivity/results and I would think that the short visit/stay cycle would never be overcome. Essentially stuck starving on five acres.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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More generally - I think you are being way too pessimistic about farming on Mars.
I personally don't think we will begin with dome farming in natural light. So, talking in terms of "acres" isn't helpful I think.
Basically farming comes down to seeds, nutrient-rich growing medium, water and energy (from the Sun or artificial lighting). If you get those four right, you literally cannot fail (although I suppose we should add that absence of gravity can pose challenges...though everything suggests growing plants in 0.38 Earth gravity should be OK).
I think we will opt for artificially lit indoor farms. We may use soil or we may use hydroponic (or similar) techniques.
For the first few missions we may import the soil and nutrient solutions. Then we will be making compost, adding in food waste and human faeces to enrich the soil.
After a few years, we will probably be manufacturing soil on Mars - crushing rock to the right grades, mixing in Mars sand and Mars clay, introducing microbes, nutrients and analogues for plant matter.
For indoor farming, the only structure we need is a pressurised space. So use the most efficient methods to do that. Maybe carving out chambers in sandstone would work. Within those chambers you can have several shelves where plants are grown in soil trays or are growing hydroponically using nutrient rich water solutions. So, within any one area you are doubling, tripling or more the "space" being used as you are growing the food on several layers. Lighting would come from LEDs producing an analogue for natural sunlight and working on timers. The air might be enriched with above normal levels of CO2 to encourage growth.
Each plant type would be given exactly the right nutrients, light, and water etc to ensure optimal development.
Here is an interesting link showing how an indoor farm actually works on Earth.
https://www.youtube.com/watch?v=H7h_qC73In0&app=desktop
Indoor farms currently appear to grow mostly salad crops but I think that is only because of commercial considerations i.e. they can compete economically with organic produce grown naturally outside. Those sorts of costs considerations will not apply on Mars where energy and land will in essenece be freely available.
So I am very optimistic about farming on Mars. I don't anyone will be starving there!
I took a tour of Mesa Verde Ruins years ago and the tour guide explained how the inhabitants farmed and on what crops they subsisted on as well as other interesting things. One thing that I found especially interesting is the story of how he and a friend decided to try to live only upon what they grew on their land. Each of the men had five acres and a water well and each worked together and rotated crops etc. Sadly, they both had to give up as they could not grow enough food to live upon. He made a point that many people had to grow different things and then share back and forth etc. within the Mesa Verde Settlement. If ten acres of prime land and endless water with clean air produces such dismal results how much harder will it be to grow enough food on Mars. I would guess that to just be able to plant and harvest on five acres on Mars one would need a massive amount of infrastructure in place first. The infrastructure I suppose could happen but not with just a handful of scientists or astronauts. Masons, Electricians, Plumbers, AC, Steel workers, Heavy Equipment Operators, and much more would need to make the trip as well. Supplies and equipment would have to be in place and a more sustainable and safe habitat would have to be constructed within 40-50 days before food shortages or air problems began. Reserves of air, water, food, first aid, and more would need to be stock piled and in quantities well above estimates in case something goes wrong for each building phase etc. and for all contractors, astronauts, scientists, and so on. Cost to build a decent sustainable, safe, and large enough habitat that would allow for a proper foothold (within the next 50-60 years), probably at least 4-6 billion here on earth, but on Mars I would estimate 5 trillion on up. If a small manned mission that is basically a short stay and minimal exploration, costs 4-5 hundred million it's easy to extrapolate out from there. Small amounts of work done by small amounts of people done over long periods of time on one seriously inhospitable planet probably doesn't equate to very good productivity/results and I would think that the short visit/stay cycle would never be overcome. Essentially stuck starving on five acres.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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More generally - I think you are being way too pessimistic about farming on Mars.
I personally don't think we will begin with dome farming in natural light. So, talking in terms of "acres" isn't helpful I think.
Basically farming comes down to seeds, nutrient-rich growing medium, water and energy (from the Sun or artificial lighting). If you get those four right, you literally cannot fail (although I suppose we should add that absence of gravity can pose challenges...though everything suggests growing plants in 0.38 Earth gravity should be OK).
I think we will opt for artificially lit indoor farms. We may use soil or we may use hydroponic (or similar) techniques.
For the first few missions we may import the soil and nutrient solutions. Then we will be making compost, adding in food waste and human faeces to enrich the soil.
After a few years, we will probably be manufacturing soil on Mars - crushing rock to the right grades, mixing in Mars sand and Mars clay, introducing microbes, nutrients and analogues for plant matter.
For indoor farming, the only structure we need is a pressurised space. So use the most efficient methods to do that. Maybe carving out chambers in sandstone would work. Within those chambers you can have several shelves where plants are grown in soil trays or are growing hydroponically using nutrient rich water solutions. So, within any one area you are doubling, tripling or more the "space" being used as you are growing the food on several layers. Lighting would come from LEDs producing an analogue for natural sunlight and working on timers. The air might be enriched with above normal levels of CO2 to encourage growth.
Each plant type would be given exactly the right nutrients, light, and water etc to ensure optimal development.
Here is an interesting link showing how an indoor farm actually works on Earth.
https://www.youtube.com/watch?v=H7h_qC73In0&app=desktop
Indoor farms currently appear to grow mostly salad crops but I think that is only because of commercial considerations i.e. they can compete economically with organic produce grown naturally outside. Those sorts of costs considerations will not apply on Mars where energy and land will in essenece be freely available.
So I am very optimistic about farming on Mars. I don't anyone will be starving there!
You are right, I was having a fairly pessimistic day yesterday. I do believe in the farming capacity of Mars and especially so with your ideas on canyon habitats. The use of gravity and water flow and vertical farming and protection from canyon walls all makes sense to me, in fact this idea of canyon habitat seems sustainable and safe. Even artificial waterfalls and canals would make engineering sense with your concept.
I still have pessimism though in regards to politicians, money, time, and peoples' fear. It's kind of like the moon missions and how they fizzled out even in the face of the peoples enthusiasm. A small moon base as a research or emergency outpost for scientists, astronauts, or tourists would have been really cool and could have been done relatively easy and inexpensively and much could have been learned, and gained. And I am not advocating for the moon I like Mars, I am just wondering if this pattern is going to play out on Mars..after a few manned missions the politicians and powers that are just pull the plug and like the people during the space race their dreams get thrown aside.
I sense that Elon Musk has got it right with the large loads being taken to Mars right from the beginning, so that serious results can be seen quickly, and excitement can grow. I also think that there needs to be some sort of reason found be it rare platinum, super conductive metals, new materials or whatever to further the case for Mars in the minds of those who hold the purse strings. And the sooner in the missions time line this is figured out the better.
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"politicians, money, time, and peoples' fear" - Yep you are right to consider those the enemy!
I agree a small lunar base would have completely changed our perspective on exploring the solar system. NASA took a huge wrong turn when it abandoned the Moon.
Personally, I feel we can't be that far from the era of lunar tourism...in fact if Musk was purely focussed on making money rather than realising an historic undertaking, he would probably be concentrating that.
I really admire Musk's vision and technical ability. But I do question his understanding of people, of group dynamics, of politics, of organising people with a multitude of needs and wants! You can't simply "dump" 50,000 people on Mars every two years - supposedly on a no-return basis. There has to be some sort of selection criteria, and I think as soon as you look at those criteria, you realise finding 50,000 people every two years who meet the criteria and are willing to give up their lives on Earth is going to be incredibly difficult....and I suspect impossible. You can probably easily find 50,000 desperadoes or mentally ill people or religious fanatics or extremely poor and uneducated people or people who overestimate their abilities or romantics...but 50,000 people with the real skills you need, the depth of character and the willingness to say goodbye to life on Earth and to the chance to raise a family? I don't think so. These people will all need extensive training remember! Quality training never comes cheap - and that seems to be something Musk hasn't factored in.
Even if you found 50,000 with the right skills and personality match, you will face huge problems of organisation on a planet where minutely controlled life support is essential.
louis wrote:More generally - I think you are being way too pessimistic about farming on Mars.
I personally don't think we will begin with dome farming in natural light. So, talking in terms of "acres" isn't helpful I think.
Basically farming comes down to seeds, nutrient-rich growing medium, water and energy (from the Sun or artificial lighting). If you get those four right, you literally cannot fail (although I suppose we should add that absence of gravity can pose challenges...though everything suggests growing plants in 0.38 Earth gravity should be OK).
I think we will opt for artificially lit indoor farms. We may use soil or we may use hydroponic (or similar) techniques.
For the first few missions we may import the soil and nutrient solutions. Then we will be making compost, adding in food waste and human faeces to enrich the soil.
After a few years, we will probably be manufacturing soil on Mars - crushing rock to the right grades, mixing in Mars sand and Mars clay, introducing microbes, nutrients and analogues for plant matter.
For indoor farming, the only structure we need is a pressurised space. So use the most efficient methods to do that. Maybe carving out chambers in sandstone would work. Within those chambers you can have several shelves where plants are grown in soil trays or are growing hydroponically using nutrient rich water solutions. So, within any one area you are doubling, tripling or more the "space" being used as you are growing the food on several layers. Lighting would come from LEDs producing an analogue for natural sunlight and working on timers. The air might be enriched with above normal levels of CO2 to encourage growth.
Each plant type would be given exactly the right nutrients, light, and water etc to ensure optimal development.
Here is an interesting link showing how an indoor farm actually works on Earth.
https://www.youtube.com/watch?v=H7h_qC73In0&app=desktop
Indoor farms currently appear to grow mostly salad crops but I think that is only because of commercial considerations i.e. they can compete economically with organic produce grown naturally outside. Those sorts of costs considerations will not apply on Mars where energy and land will in essenece be freely available.
So I am very optimistic about farming on Mars. I don't anyone will be starving there!
You are right, I was having a fairly pessimistic day yesterday. I do believe in the farming capacity of Mars and especially so with your ideas on canyon habitats. The use of gravity and water flow and vertical farming and protection from canyon walls all makes sense to me, in fact this idea of canyon habitat seems sustainable and safe. Even artificial waterfalls and canals would make engineering sense with your concept.
I still have pessimism though in regards to politicians, money, time, and peoples' fear. It's kind of like the moon missions and how they fizzled out even in the face of the peoples enthusiasm. A small moon base as a research or emergency outpost for scientists, astronauts, or tourists would have been really cool and could have been done relatively easy and inexpensively and much could have been learned, and gained. And I am not advocating for the moon I like Mars, I am just wondering if this pattern is going to play out on Mars..after a few manned missions the politicians and powers that are just pull the plug and like the people during the space race their dreams get thrown aside.
I sense that Elon Musk has got it right with the large loads being taken to Mars right from the beginning, so that serious results can be seen quickly, and excitement can grow. I also think that there needs to be some sort of reason found be it rare platinum, super conductive metals, new materials or whatever to further the case for Mars in the minds of those who hold the purse strings. And the sooner in the missions time line this is figured out the better.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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"politicians, money, time, and peoples' fear" - Yep you are right to consider those the enemy!
I agree a small lunar base would have completely changed our perspective on exploring the solar system. NASA took a huge wrong turn when it abandoned the Moon.
Personally, I feel we can't be that far from the era of lunar tourism...in fact if Musk was purely focussed on making money rather than realising an historic undertaking, he would probably be concentrating that.
I really admire Musk's vision and technical ability. But I do question his understanding of people, of group dynamics, of politics, of organising people with a multitude of needs and wants! You can't simply "dump" 50,000 people on Mars every two years - supposedly on a no-return basis. There has to be some sort of selection criteria, and I think as soon as you look at those criteria, you realise finding 50,000 people every two years who meet the criteria and are willing to give up their lives on Earth is going to be incredibly difficult....and I suspect impossible. You can probably easily find 50,000 desperadoes or mentally ill people or religious fanatics or extremely poor and uneducated people or people who overestimate their abilities or romantics...but 50,000 people with the real skills you need, the depth of character and the willingness to say goodbye to life on Earth and to the chance to raise a family? I don't think so. These people will all need extensive training remember! Quality training never comes cheap - and that seems to be something Musk hasn't factored in.
Even if you found 50,000 with the right skills and personality match, you will face huge problems of organisation on a planet where minutely controlled life support is essential.
I agree with you there. I think it would be a good idea to drop off all the materials and tools needed to build one of those canyons you are talking about as well as an underground bunker/habitat that was connected to the green canyon. Instead of 50,000 people they ought to send a hundred contractors and a handful of scientists and everything that these people would need to get a safe and strong permanent structure built first. Then I think the realistic settlement process could safely begin. I know that the preliminary stuff would have to happen first, I just think that the above ought to happen before all the people get dumped there.
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I have to say Tony that I don't envisage canyons as being a first stop for the Mars colony. Personally I think it goes:
1. Lander craft
2. Inflatable home habitats.
3. Cut and cover habitats (dig a trench and put a roof over).
4. Tunnels and sandstone enclaves.
5. Glass or perspex domes.
6. Canyons.
louis wrote:"politicians, money, time, and peoples' fear" - Yep you are right to consider those the enemy!
I agree a small lunar base would have completely changed our perspective on exploring the solar system. NASA took a huge wrong turn when it abandoned the Moon.
Personally, I feel we can't be that far from the era of lunar tourism...in fact if Musk was purely focussed on making money rather than realising an historic undertaking, he would probably be concentrating that.
I really admire Musk's vision and technical ability. But I do question his understanding of people, of group dynamics, of politics, of organising people with a multitude of needs and wants! You can't simply "dump" 50,000 people on Mars every two years - supposedly on a no-return basis. There has to be some sort of selection criteria, and I think as soon as you look at those criteria, you realise finding 50,000 people every two years who meet the criteria and are willing to give up their lives on Earth is going to be incredibly difficult....and I suspect impossible. You can probably easily find 50,000 desperadoes or mentally ill people or religious fanatics or extremely poor and uneducated people or people who overestimate their abilities or romantics...but 50,000 people with the real skills you need, the depth of character and the willingness to say goodbye to life on Earth and to the chance to raise a family? I don't think so. These people will all need extensive training remember! Quality training never comes cheap - and that seems to be something Musk hasn't factored in.
Even if you found 50,000 with the right skills and personality match, you will face huge problems of organisation on a planet where minutely controlled life support is essential.
I agree with you there. I think it would be a good idea to drop off all the materials and tools needed to build one of those canyons you are talking about as well as an underground bunker/habitat that was connected to the green canyon. Instead of 50,000 people they ought to send a hundred contractors and a handful of scientists and everything that these people would need to get a safe and strong permanent structure built first. Then I think the realistic settlement process could safely begin. I know that the preliminary stuff would have to happen first, I just think that the above ought to happen before all the people get dumped there.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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I have to say Tony that I don't envisage canyons as being a first stop for the Mars colony. Personally I think it goes:
1. Lander craft
2. Inflatable home habitats.
3. Cut and cover habitats (dig a trench and put a roof over).
4. Tunnels and sandstone enclaves.
5. Glass or perspex domes.
6. Canyons.
So this is where I need some clarification, 1-5 to me seem like a logical progression that takes place while food is being dropped off periodically and people are staying but for fairly short durations, then returning back to earth and so on until number six happens and people actually stay for extended periods of time like 1-5 years until they truly know the long term effects of Mars on the human body and if all is well then people start making the red planet home. But from what I have been reading in various posts it seems like the plan is more like 2-3 people are already making Mars home. When do you see (in the above progression)people actually self reliant and living permanently on Mars? And at what point is there enough redundant life support on Mars in all various forms that people don't die if a rocket doesn't make a return trip on time?
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I took a tour of Mesa Verde Ruins years ago and the tour guide explained how the inhabitants farmed and on what crops they subsisted on as well as other interesting things. One thing that I found especially interesting is the story of how he and a friend decided to try to live only upon what they grew on their land. Each of the men had five acres and a water well and each worked together and rotated crops etc. Sadly, they both had to give up as they could not grow enough food to live upon. He made a point that many people had to grow different things and then share back and forth etc. within the Mesa Verde Settlement. If ten acres of prime land and endless water with clean air produces such dismal results how much harder will it be to grow enough food on Mars.
Did a web search on how much land to sustain a person and found this:
How Much Land Does It Take To Be Self-Reliant?
November 15, 2012 By M.D. Creekmore
The research to the answer to that question was started back in the 70’s by a man named John Jeavons. The “Bio-Intensive” method Jeavons developed has been implemented worldwide to alleviate hunger and malnutrition. Jeavons has a model for a vegetarian diet and the short answer is summarized as approximately 8,000 sq.ft. for a complete diet for one person (you need 4,000 sq/ft. of actual growing space and at least 4,000 sq.ft. for pathways and access). That is also assuming you have four growing seasons per year, and your harvest is 100% (no failures).
For reference, an acre is 43,560 sq.ft. So in a more southern climate, you could theoretically support about 5 people per acre. But life is never that perfect. My personal experience is that 2 acres in a mild temperate region will completely wear you out and is enough room to comfortably support a family of four with a variety of food sources such as gardens, orchards, small livestock, and wild crafting. You can still do a lot in less area, and of course, everyone always wants more.
http://www.thesurvivalistblog.net/how-m … f-reliant/
Perhaps the Mesa Verde land wasn't very arable or those working it weren't experienced farmers.
Bob Clark
Old Space rule of acquisition (with a nod to Star Trek - the Next Generation):
“Anything worth doing is worth doing for a billion dollars.”
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I think, as you say, we don't really know the health effects of living on Mars for extended period. Before people can truly be said to be living on Mars on a permanent basis, we need to know if they can reproduce and whether foetal development is unaffected. There may be some fixes e.g. perhaps women will got to a Mars orbiting artificial 1G craft while pregnant. So a lot is dependent on health effects. We know the immune system is to some extent compromised by zero G space flight. Is that because of zero G? Or because people are isolated from the pathogens constantly testing their immune response on Earth. Actually disease is another good reason for not just dumping 50,000 people on Earth every 2 years. Even if people pass a thorough medical they could be harbouring pathogens that are then expressed on Mars.
So health is the prime determinant.
Assuming we live healthily on Mars I would say we should be working towards something like 95% self-sufficiency (i.e. on 5% of total mass "consumed" is imported from Earth - things like spacesuits, medicines, computers) from Mission 1. There is no reason why an experimental indoor farm hab can't be landed with Mission 1.
I see no reason why we couldn't achieve 95% self sufficiency at stage 3. However, in reality I suspect a slower build up. I actually think the Mars economy will be strong and will be able to pay for plenty of imports.
louis wrote:I have to say Tony that I don't envisage canyons as being a first stop for the Mars colony. Personally I think it goes:
1. Lander craft
2. Inflatable home habitats.
3. Cut and cover habitats (dig a trench and put a roof over).
4. Tunnels and sandstone enclaves.
5. Glass or perspex domes.
6. Canyons.
So this is where I need some clarification, 1-5 to me seem like a logical progression that takes place while food is being dropped off periodically and people are staying but for fairly short durations, then returning back to earth and so on until number six happens and people actually stay for extended periods of time like 1-5 years until they truly know the long term effects of Mars on the human body and if all is well then people start making the red planet home. But from what I have been reading in various posts it seems like the plan is more like 2-3 people are already making Mars home. When do you see (in the above progression)people actually self reliant and living permanently on Mars? And at what point is there enough redundant life support on Mars in all various forms that people don't die if a rocket doesn't make a return trip on time?
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Nice conversation, and I intend to stay out of it except to query about vitamin B12 deficiency.
http://www.webmd.com/food-recipes/news/ … ficiency#1
The consequences could be rather serious. Maybe someone already knows how to cover this. That would be great.
Some might suggest eating small animals, such as bugs?, Worms? Yuck.
I myself would incorporate a chemosynthetic path as part of your food. Impaler suggested such a route for a source of protein, and to me that makes sense. I also would hope to produce a artificial Methane seep in a small body of salt water, to grow clams. I am supposing that clams might supply B12.
Both the protein and clams would grow from Methane perhaps. The clams of course will need Oxygen.
If there are better notions, then I would be all for that, but diversification is not a bad idea anyway. Some food from solar greenhouses, some from artificial light greenhouses, and some from Chemosynthesis.
Done.
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There are some points where I agree with louis and some on which I disagree. Land near a colony won't be quite free because of opportunity costs. For example, if you decide to put a greenhouse on one sunny outcropping, you can't put a solar power facility there. It is desirable for both of these to be close to living space.
Having said that, Mars has as much land as Earth and will have virtually no people. Empty, unimproved land has very little opportunity cost or value.
What does have value is pressurized volume. Even moreso than on Earth, indoor space will be expensive to build and maintain. Indoor space will probably be at a pressure of about half an atmosphere. This is 50,000 Newtons per square meter or about half a US ton per square foot.
One thing that matters is therefore going to be efficient use of internal space. It was noted above that 50% of the area of Terran farms is used for human access. By growing the crops in trays (whether they be hydroponic or aeroponic), 0% of the space could be used for human access and the crops could be on rails so that they move out of the way as needed for human access or harvesting.
The greenhouses will probably be circular in cross-section. It might make sense to lift them up off the ground and point mirrors at them on the bottom.
What will not make sense is to use grow lights. The reason why is systemic inefficiency. Here's a representative idea:
Solar panels or concentrated solar power plants will be about 20% efficient at converting sunlight into electrical energy
LEDs will be maybe 20% efficient
Put together, this is a systemic efficiency of 4%. This means you need 25 times as much area in power generation plants as you would in greenhouse. There will also be some losses if you're using mirrors but not as much, so perhaps 20 times as much power generation area as mirror area.
I just said that land area isn't expensive, so you would think this would be a good trade. But think about what this really means: Instead of building a greenhouse, you're building power plants. Louis likes to claim that electrical energy will be abundant on Mars, but "abundant" and "free/cheap" are not the same thing. In fact, we know from economics that as demand goes up price also tends to go up. 8000 square feet is about 800 square meters. At Earthlike levels of illumination, each square meter will see 17.3 MJ (5 kWh) of light energy per day. This adds up over time to a lot of wasted energy for no real reason.
Louis and I have discussed this before and we didn't get much of anywhere. I believe that his approach on this topic is wrong and I would like to push back here so that you all can at least see the counterpoint.
-Josh
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There are some points where I agree with louis and some on which I disagree. Land near a colony won't be quite free because of opportunity costs. For example, if you decide to put a greenhouse on one sunny outcropping, you can't put a solar power facility there. It is desirable for both of these to be close to living space.
Having said that, Mars has as much land as Earth and will have virtually no people. Empty, unimproved land has very little opportunity cost or value.
What does have value is pressurized volume. Even moreso than on Earth, indoor space will be expensive to build and maintain. Indoor space will probably be at a pressure of about half an atmosphere. This is 50,000 Newtons per square meter or about half a US ton per square foot.
One thing that matters is therefore going to be efficient use of internal space. It was noted above that 50% of the area of Terran farms is used for human access. By growing the crops in trays (whether they be hydroponic or aeroponic), 0% of the space could be used for human access and the crops could be on rails so that they move out of the way as needed for human access or harvesting.
The greenhouses will probably be circular in cross-section. It might make sense to lift them up off the ground and point mirrors at them on the bottom.
What will not make sense is to use grow lights. The reason why is systemic inefficiency. Here's a representative idea:
Solar panels or concentrated solar power plants will be about 20% efficient at converting sunlight into electrical energy
LEDs will be maybe 20% efficientPut together, this is a systemic efficiency of 4%. This means you need 25 times as much area in power generation plants as you would in greenhouse. There will also be some losses if you're using mirrors but not as much, so perhaps 20 times as much power generation area as mirror area.
I just said that land area isn't expensive, so you would think this would be a good trade. But think about what this really means: Instead of building a greenhouse, you're building power plants. Louis likes to claim that electrical energy will be abundant on Mars, but "abundant" and "free/cheap" are not the same thing. In fact, we know from economics that as demand goes up price also tends to go up. 8000 square feet is about 800 square meters. At Earthlike levels of illumination, each square meter will see 17.3 MJ (5 kWh) of light energy per day. This adds up over time to a lot of wasted energy for no real reason.
Louis and I have discussed this before and we didn't get much of anywhere. I believe that his approach on this topic is wrong and I would like to push back here so that you all can at least see the counterpoint.
When I read this I had a question arise. Can we breath the air in greenhouses without any supplementation and also will the oxygen build up to unsafe levels? If it does would we have to vent the oxygen and if this is the case then won't we loose the nitrogen and I read in other posts that Mars really needs nitrogen? If there is a way to do these things would it use up a lot of energy?
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TonyTMarsBeginner wrote:I took a tour of Mesa Verde Ruins years ago and the tour guide explained how the inhabitants farmed and on what crops they subsisted on as well as other interesting things. One thing that I found especially interesting is the story of how he and a friend decided to try to live only upon what they grew on their land. Each of the men had five acres and a water well and each worked together and rotated crops etc. Sadly, they both had to give up as they could not grow enough food to live upon. He made a point that many people had to grow different things and then share back and forth etc. within the Mesa Verde Settlement. If ten acres of prime land and endless water with clean air produces such dismal results how much harder will it be to grow enough food on Mars.
Did a web search on how much land to sustain a person and found this:
How Much Land Does It Take To Be Self-Reliant?
November 15, 2012 By M.D. CreekmoreThe research to the answer to that question was started back in the 70’s by a man named John Jeavons. The “Bio-Intensive” method Jeavons developed has been implemented worldwide to alleviate hunger and malnutrition. Jeavons has a model for a vegetarian diet and the short answer is summarized as approximately 8,000 sq.ft. for a complete diet for one person (you need 4,000 sq/ft. of actual growing space and at least 4,000 sq.ft. for pathways and access). That is also assuming you have four growing seasons per year, and your harvest is 100% (no failures).
For reference, an acre is 43,560 sq.ft. So in a more southern climate, you could theoretically support about 5 people per acre. But life is never that perfect. My personal experience is that 2 acres in a mild temperate region will completely wear you out and is enough room to comfortably support a family of four with a variety of food sources such as gardens, orchards, small livestock, and wild crafting. You can still do a lot in less area, and of course, everyone always wants more.http://www.thesurvivalistblog.net/how-m … f-reliant/
Perhaps the Mesa Verde land wasn't very arable or those working it weren't experienced farmers.
Bob Clark
I failed mention in my post that they wanted to use the same technology as the Native Americans of the area and not modern equipment or fertilizers etc., which may or may not carry over to Mars..
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When I read this I had a question arise. Can we breath the air in greenhouses without any supplementation and also will the oxygen build up to unsafe levels? If it does would we have to vent the oxygen and if this is the case then won't we loose the nitrogen and I read in other posts that Mars really needs nitrogen? If there is a way to do these things would it use up a lot of energy?
Opinions vary on this, but I believe that there's a clear answer. I believe the right answer is to use the greenhouses as the lungs of the colony. The greenhouse would therefore have the same atmosphere as anywhere else, and you would cycle the air through to clean it and to reduce the amount of Carbon Dioxide.
This also means that you can work in the greenhouses in shirtsleeves instead of with a respirator. I expect that the CO2 levels in the colony would be on the high-ish side relative to indoor space on Earth to facilitate plant growth.
The cool thing about using greenhouses as the lungs of a colony is that if you're using them to produce food, the CO2 produced by respiration will tend to equal the amount of O2 produced by photosynthesis.
-Josh
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Well I agree with a lot of what you say, if not everything...
I don't think 50% of agricultural land on Earth is devoted to access (think of the N American prairies). I think that figure related more to a single plot for total subsistence farming - i.e. farming lots of different crops on the one plot (clearly you would need lots of access points).
In the early colony there won't be "cost" as we understand it on Mars - and so the "supply and demand" price determination process won't apply. There will be allocation of resources - and the chief of those is labour time.
I accept the power demand of indoor farming will be huge, probably something of the order you claim. However, there is little difficulty in supplying that power on Mars: we can deliver the PV panels and methane manufacture plants, which can then operate automatically.
You make "building a greenhouse" sound simple. If everything is to be manufactured on Mars it will be an incredibly labour-intensive undertaking compared with creating indoor farming chambers using quick cut and cover techniques. I guess you can probably send inflatable greenhouses of some description to Mars. But then you are having to import mass.
But the main issue with greenhouses is that you are dependent on the natural variation in light on Mars. A dust storm will affect your agricultural output. Your crops have to meet what's on offer - whereas with indoor forming you can have tropical, sub tropical or temperate growing conditions. Also, in terms of labour time harvesting the crops will in all likelihood be more demanding inside greenhouses.
I have no doubt greenhouses will come into their own over time but for the early years of the colony I think indoor farming wins out.
There are some points where I agree with louis and some on which I disagree. Land near a colony won't be quite free because of opportunity costs. For example, if you decide to put a greenhouse on one sunny outcropping, you can't put a solar power facility there. It is desirable for both of these to be close to living space.
Having said that, Mars has as much land as Earth and will have virtually no people. Empty, unimproved land has very little opportunity cost or value.
What does have value is pressurized volume. Even moreso than on Earth, indoor space will be expensive to build and maintain. Indoor space will probably be at a pressure of about half an atmosphere. This is 50,000 Newtons per square meter or about half a US ton per square foot.
One thing that matters is therefore going to be efficient use of internal space. It was noted above that 50% of the area of Terran farms is used for human access. By growing the crops in trays (whether they be hydroponic or aeroponic), 0% of the space could be used for human access and the crops could be on rails so that they move out of the way as needed for human access or harvesting.
The greenhouses will probably be circular in cross-section. It might make sense to lift them up off the ground and point mirrors at them on the bottom.
What will not make sense is to use grow lights. The reason why is systemic inefficiency. Here's a representative idea:
Solar panels or concentrated solar power plants will be about 20% efficient at converting sunlight into electrical energy
LEDs will be maybe 20% efficientPut together, this is a systemic efficiency of 4%. This means you need 25 times as much area in power generation plants as you would in greenhouse. There will also be some losses if you're using mirrors but not as much, so perhaps 20 times as much power generation area as mirror area.
I just said that land area isn't expensive, so you would think this would be a good trade. But think about what this really means: Instead of building a greenhouse, you're building power plants. Louis likes to claim that electrical energy will be abundant on Mars, but "abundant" and "free/cheap" are not the same thing. In fact, we know from economics that as demand goes up price also tends to go up. 8000 square feet is about 800 square meters. At Earthlike levels of illumination, each square meter will see 17.3 MJ (5 kWh) of light energy per day. This adds up over time to a lot of wasted energy for no real reason.
Louis and I have discussed this before and we didn't get much of anywhere. I believe that his approach on this topic is wrong and I would like to push back here so that you all can at least see the counterpoint.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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I think a company named Omega Garden has already solutioned the problem of initial farming efforts on Mars for us. It's a commercial product that uses a central illumination source with the crops positioned around the light source.
The Omega Garden produces one pound of food using 150ft^2 of floor space and .38kWh's worth of electrical power using LED lighting. One average person on ISS requires a little less than four pounds of food per day, so that's 600ft^2 and 1.52kWh to feed one person per day. The individual carousels are roughly 2ft in diameter and 4ft long, although that could obviously be varied to suit the type of crop being grown. A 5M x 10M cylinder could easily hold enough of these carousels to provide a variety of fresh produce for our astronauts or colonists. It wouldn't be a complete replacement for food imported from Earth, but it would be a great start. The waste from the crops should be shredded and pumped into a biogas generator to provide heat and power for the greenhouse. Again, it's not a complete solution but it's a pretty good start.
As far as power is concerned, any substantial surface colony requires a nuclear reactor. No other power source remotely approaches the output capacity of a fission reactor with a similar mass when hundreds of kilowatts to megawatts of power are required. If solar panels were 100% efficient, a fission reactor would still provide more power for less mass with a colony's power requirements.
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I don't think 50% of agricultural land on Earth is devoted to access (think of the N American prairies). I think that figure related more to a single plot for total subsistence farming - i.e. farming lots of different crops on the one plot (clearly you would need lots of access points).
I agree that 50% is an exaggerated figure. Regardless though I think it makes sense to try to get as much use from greenhouse space as possible and therefore my rail system (or some other system that accomplishes the same thing) makes sense.
In the early colony there won't be "cost" as we understand it on Mars - and so the "supply and demand" price determination process won't apply. There will be allocation of resources - and the chief of those is labour time.
You're right in a sort of limited sense. The early Martian colony won't be capitalist in the same way as we are here on Earth. However, certain things that are true about economic development on Earth are also true on Mars.
One of these is the general shape of the marginal cost curve, e.g. given that you already produce X amount of good Y, how much it costs to produce one more.
Naturally, you will put your first solar panels in the best spot you can find. Ideally, you want them to be in a place near where the power is needed, in a place that's relatively resilient to airborne dust, south-facing in the northern hemisphere and north-facing in the southern hemisphere, on flat ground, etc.
As you need more and more panels, the best places to put them will get used up. You will then have to go to places that are less and less good. Therefore output goes down or costs (however you'd like to measure them) go up.
Mars doesn't have to be capitalist in the same way Earth is for things like cost and value to make sense. A Mars colony is going to have to produce exports to pay for its imports. There will be some marginal labor cost to each dollar in imports/exports. Even if the colony is in a foundational stage, that money will have to be paid back eventually and there's no reason to spend more money than you have to. Investments in the colony take the form of money now for labor later.
Importing solar panels is not free. Neither is importing grow lights.
I accept the power demand of indoor farming will be huge, probably something of the order you claim. However, there is little difficulty in supplying that power on Mars: we can deliver the PV panels and methane manufacture plants, which can then operate automatically.
See above. Just because it's not "difficult" (Sending anything to mars is a relatively difficult technological feat no matter what it is) doesn't mean it'll be cheap.
You make "building a greenhouse" sound simple. If everything is to be manufactured on Mars it will be an incredibly labour-intensive undertaking compared with creating indoor farming chambers using quick cut and cover techniques.
I guess you can probably send inflatable greenhouses of some description to Mars. But then you are having to import mass.
Cut and cover is not a viable way to build pressure vessels.
The problem with using cut and cover to build habitable space is that the ground is not a structural element. It can move when force is exerted on it. Half an atmosphere is equal to 5 tonnes per square meter. That's rather more than a bulldozer. What this means is that you need to use load bearing elements to hold the pressure in in two directions. I have described my vision for enclosed spaces in this post.
Basically, non-greenhouse space ends up being somewhat easier to build because you need to contain pressure in two ordinate directions but not in three. The difference matters but it's also easy to overstate. Back-of-the-envelope suggests that a given volume of greenhouse will be 50% more expensive than an equivalent volume of non-greenhouse. There are other factors that could make it more or less. It's meaningful but not huge.
If you're importing your shelters, it's sort of a wash in terms of how hard they are to build. In both cases they would probably be inflatable and the difference is only in where you put them.
I envision that greenhouses would be constructed as follows:
Mount each glass pane on a frame element
Build the greenhouse by putting together the frames
Wrap steel rope (like you see in suspension bridges) around the frame
Increase pressure in the greenhouse up to hab pressure
I am not in the construction industry but I'm sure the Martians will be quite clever in developing ways to put greenhouses together in the most cost-effective and safe way possible.
But the main issue with greenhouses is that you are dependent on the natural variation in light on Mars. A dust storm will affect your agricultural output. Your crops have to meet what's on offer - whereas with indoor forming you can have tropical, sub tropical or temperate growing conditions. Also, in terms of labour time harvesting the crops will in all likelihood be more demanding inside greenhouses.
The funny thing about solar energy is that it's actually impacted by dust storms much more than a greenhouse would be. Solar panels and concentrated solar power both function best with direct sunlight. Direct sunlight is cut down to nearly zero during dust storms, while indirect sunlight increases (relative to non-dust storm times. Total illumination is of course lower). Plants are good with indirect sunlight.
You propose using methane to keep the lights on during dust storms. I actually agree with you here--And I believe this is one of the strongest arguments against what you're proposing.
Consider what it actually takes to make methane. The "fuel" for the sabatier process is Hydrogen, which comes from electrolyzing water. This process is about 60% efficient. After that, you do the sabatier reaction. The sabatier reaction is 75% efficient at using the chemical energy of the Hydrogen. Then you store the methane, only to burn it at a later date to create energy. This process is about 25% efficient. All told, you lose about 90% of the initial electrical energy. The process sunlight->electrical energy->Hydrogen->methane->electrical energy->light is therefore about 0.4% efficient as a whole.
By whatever measure of cost, then, electrical energy for a solar powered colony is at least ten times as expensive during a dust storm. But it's actually more than that. In addition to the additional electrical energy, you also need to generate the methane in a sabatier reactor. You need to refrigerate and store it as well as liquid oxygen, both of which take energy. Then you need to burn it and convert the thermal energy to electrical energy*. This requires either more equipment made by the colony or imported. It's definitely not unreasonable to say that electrical energy will be twenty times as pricey during a dust storm, and possibly more.
So you're taking something that's already a major cost and multiplying it by twenty.
Light levels in an ambient light greenhouse can be expected to decline, perhaps by as much as 70%. Maybe more if you're using concentrating mirrors. But the plants will probably survive, and it actually makes more sense to store energy as food than to store it as methane and oxygen.
*This is one of several reasons why I think the colony should use solar power towers when it starts building its own power generation systems. In the event of a dust storm you're using a different heat source but get to use the same machinery instead of having a backup set.
-Josh
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There are some points where I agree with louis and some on which I disagree. Land near a colony won't be quite free because of opportunity costs. For example, if you decide to put a greenhouse on one sunny outcropping, you can't put a solar power facility there. It is desirable for both of these to be close to living space.
Having said that, Mars has as much land as Earth and will have virtually no people. Empty, unimproved land has very little opportunity cost or value.
What does have value is pressurized volume. Even moreso than on Earth, indoor space will be expensive to build and maintain. Indoor space will probably be at a pressure of about half an atmosphere. This is 50,000 Newtons per square meter or about half a US ton per square foot.
One thing that matters is therefore going to be efficient use of internal space. It was noted above that 50% of the area of Terran farms is used for human access. By growing the crops in trays (whether they be hydroponic or aeroponic), 0% of the space could be used for human access and the crops could be on rails so that they move out of the way as needed for human access or harvesting.
The greenhouses will probably be circular in cross-section. It might make sense to lift them up off the ground and point mirrors at them on the bottom.
What will not make sense is to use grow lights. The reason why is systemic inefficiency. Here's a representative idea:
Solar panels or concentrated solar power plants will be about 20% efficient at converting sunlight into electrical energy
LEDs will be maybe 20% efficientPut together, this is a systemic efficiency of 4%. This means you need 25 times as much area in power generation plants as you would in greenhouse. There will also be some losses if you're using mirrors but not as much, so perhaps 20 times as much power generation area as mirror area.
I just said that land area isn't expensive, so you would think this would be a good trade. But think about what this really means: Instead of building a greenhouse, you're building power plants. Louis likes to claim that electrical energy will be abundant on Mars, but "abundant" and "free/cheap" are not the same thing. In fact, we know from economics that as demand goes up price also tends to go up. 8000 square feet is about 800 square meters. At Earthlike levels of illumination, each square meter will see 17.3 MJ (5 kWh) of light energy per day. This adds up over time to a lot of wasted energy for no real reason.
Louis and I have discussed this before and we didn't get much of anywhere. I believe that his approach on this topic is wrong and I would like to push back here so that you all can at least see the counterpoint.
Bouncing light off mirrors is an interesting idea for greenhouses and other applications as well. I wonder how the light intensity is affected by distance and number of bounces, for instance could mirrors be used on a canyon side to bounce light to another mirror on canyon bottom and back up through the floor of a green house, then bounced throughout the structure, would the light keep decreasing?
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Found this after web search:
/ The Mars Society / Technical Task Force / Life Support Project /
According to accumulated CELSS research, under optimal
conditions, it takes an average
of 23 m2 (about 250 square feet or 16' x 16') of
optimal plant growing surface space to
adequately provide for the food, air water, and waste
treatment requirements for one
person in a Controlled Ecological Life Support System
(CELSS). A family of 4
vegetarians, living on Mars (or Earth for that
matter), requires about 2000 square feet
dedicated to intensive gardening. If you plan to eat
meat and/or dairy products, remember
that animals need a lot more room than plants to
produce the same amount of food.
http://home.marssociety.org/tech/test/l … rc/s25.htm
Bob Clark
Old Space rule of acquisition (with a nod to Star Trek - the Next Generation):
“Anything worth doing is worth doing for a billion dollars.”
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It's a fair approximation to say that a mirror will reflect 90% of incident light if it's inside, 80% if it's outside and cleaned frequently, 70% if it's outside and cleaned infrequently.
You actually don't want to reflect too much light at your greenhouse. They're probably going to be pretty much equatorial, and Mars receives 45% as much sunlight as Earth (plus the difference in atmospheric effects, so Mars does a bit better than that relative to Earth). This means that just doubling the light levels means as much light as anywhere on Earth.
Having said that though, mirrors in exchange for more efficient use of greenhouse space (plants grow faster in higher light levels) is actually a pretty good trade. You might want to have more light than earth in the greenhouses.
-Josh
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It's a fair approximation to say that a mirror will reflect 90% of incident light if it's inside, 80% if it's outside and cleaned frequently, 70% if it's outside and cleaned infrequently.
You actually don't want to reflect too much light at your greenhouse. They're probably going to be pretty much equatorial, and Mars receives 45% as much sunlight as Earth (plus the difference in atmospheric effects, so Mars does a bit better than that relative to Earth). This means that just doubling the light levels means as much light as anywhere on Earth.
Having said that though, mirrors in exchange for more efficient use of greenhouse space (plants grow faster in higher light levels) is actually a pretty good trade. You might want to have more light than earth in the greenhouses.
I was thinking about the green houses and wondering if it would work to put a few of them down in a canyon for protection against wind and so on and then thought about the CO2 then came across some interesting information:
"Cryptogamic covers are responsible for about half of the naturally occurring nitrogen fixation on land and they take up as much carbon dioxide as is released yearly from biomass burning. These new findings will help to improve global flux calculations and climate models, in which up to now the carbon and nitrogen balance of the cryptogamic covers have been neglected.
The roles that forests and oceans play in the climate and in the global exchange of oxygen, carbon, and nitrogen have been documented in numerous scientific studies. The importance of algae that grow on land, lichens, and mosses for the nitrogen and carbon fluxes and also for the carbon dioxide balance is normally not taken into consideration. This even though cryptogamic covers including the blue green algae (cyanobacteria) cover approximately 30% of soil surface that includes the surfaces of plants. Life forms that get their energy through photosynthesis, but don’t flower, belong to the cryptogams. They are found in all ecosystems, not just on roofs, trees, or walls. Cryptogamic covers, which consist of some of the oldest life forms on our Planet, are also found on cliffs and in soils in dry regions."
It might be an interesting idea to include some of these cryptogamic covers into your green houses somehow?
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Pretty meaningless unless you indicate how the ceiling is. Is it a mile high? Or one foot high?
That 16x16 ft. figure looks way too small to me if you are talking about one stratum - as opposed to multi-layer growing. And we need to know what we are growing. A wide ranging diet is important for both physical and mental health.
Found this after web search:
/ The Mars Society / Technical Task Force / Life Support Project /
According to accumulated CELSS research, under optimal
conditions, it takes an average
of 23 m2 (about 250 square feet or 16' x 16') of
optimal plant growing surface space to
adequately provide for the food, air water, and waste
treatment requirements for one
person in a Controlled Ecological Life Support System
(CELSS). A family of 4
vegetarians, living on Mars (or Earth for that
matter), requires about 2000 square feet
dedicated to intensive gardening. If you plan to eat
meat and/or dairy products, remember
that animals need a lot more room than plants to
produce the same amount of food.http://home.marssociety.org/tech/test/l … rc/s25.htm
Bob Clark
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Sure does make you wonder when 5 acres they starved.....
This gardening foot print will really need to be nailed down as we do need a diet that we can not only live on but stay healthy on.....
We can not say that the item on the menu of the day after day is a salad and expect to stay healthy....
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I did try to work out greenhouse area. However, it assumed climate controlled greenhouse that could produce continuously all year. That is a huge difference.
Crops - area
Crops - menu
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