Crops

RobertDyck · 2017-08-11 08:24:28

How much energy is necessary to create synthetic fibres. Remember, there is no oil on Mars. You can convert CO2 and H2 into ethylene, then use that to build-up various plastics. But hydrogen on Mars will be generated by electrolysis of water. That requires a lot of power. Yes, it will be done, but then compare that to natural fibres.

An alternate suggestion is hemp. Industrial hemp is related to marijuana about as much poppy seeds for a bagel are related to heroin. Industrial hemp doesn't have THC, but does produce a lot of fibre. This is the Mars Society, we could get very technical, but bottom line is you have as much chance of getting high from industrial hemp as smoking lawn clippings from your front lawn. Before invention of nylon it was the only source of rope. Fibres are the length of the stem, so very strong. I have a couple hemp T-shirts. The US Declaration of Independence was written on hemp paper. Hemp seeds are a health food.

Others in the Mars Society have suggested bamboo. It grows faster than other wood products, and can be used for many things.

RobertDyck · 2017-08-11 09:09:39

Large scale cotton harvester...
the+development+of+the+cotton+picker+has+helped+farmers+harvest+their+crops+more+effectively+john+deere+has+been+at+the+forefront+of+this+technology+a_2034_800628598_0_0_14009526_300.jpg

Small scale...

elderflower · 2017-08-11 11:54:14

And what is the production per manhour of each, Robert?
People are going to be in short supply due to the expense of supporting them -until Mars is terraformed. This will be true even if Musk gets down to his dream transportation cost.
Energy is going to be relatively cheaper, whether it is nuclear fission, nuclear fusion or solar. So making polyethylene or some other artificial fibre is going to be easier for quite a long time.

Oldfart1939 · 2017-08-11 12:12:59

A major by-product of all these agricultural crops is OXYGEN.

IanM · 2017-08-11 12:13:00

I agree that many natural and synthetic fibers will be used for making clothes, especially before animal products such as leather and wool become readily available. I think flax will also be used. In addition to its use in linen, flax seeds can be used for food or making oil, and its stems can be used as paper for some purposes.

elderflower · 2017-08-11 13:30:19

Indeed Oxygen is made by crops. It is also consumed by crops when they decay (eaten by microorganisms or fungi) in the compost heap or in soil, or in human guts and faeces. You could prevent this by stacking all the waste outside to freeze dry but then you can't use it for soil improvement.
Oxygen is also a byproduct of electrolysis of water for the extraction or recovery of hydrogen for chemical feedstock.

RobertDyck · 2017-08-11 17:02:27

Of course you realize sizes I posted in this thread were sized for the Mars Homestead Project - Hillside Settlement. That means 12 people in the permanent base, who will then double to 24 people, who would then prepare to receive the first 100. Greenhouse size that I calculated was for 12 people. Using IanM's numbers, and assuming you need what Ian listed every year, that would require 1,644 square metres. That's a lot. I don't go through 2 dress shirts, 10 T-shirts, and 5 pairs of jeans every year.

Assuming each year a base of 12 people, each person would get 7 pairs of men's briefs and 7 pairs of socks (IanM's number), 1 dress shirt every other year, 2 T-shirts, 1 pair jeans, and a new set of bed sheets/pillowcases (2 each) every 4 years. I have 4 sets of bed stuff, washed and cared for over 2 decades. They really need replacing. Add 1 terry bath towel per person every 4 years. That reduces a 12-person base to 0.1707640 bales = 82 pounds of cotton per year. IanM's link said in 2015 yield was 709 pounds per acre, so 467.85 square metres. This is in an environmentally controlled greenhouse, so 2 crops per Earth year cuts it in half again: 233.625 square metres.

Of course to prepare to receive MCT with 100 settlers every time the planets align (26 months) means we will need everything IanM listed. At least with one crop every 6 months we should be able to cut greenhouse area to a quarter of what he stated. But if the 12-person base is providing for settlers, then they'll need what I listed for themselves in addition.

louis · 2017-08-11 18:05:53

There will in my view be a very high level of automation on Mars in the early settlement. It will be an energy rich automated (ERA) economy. I agree with you that energy will be substituted for labour (comparing the Mars average with the Earth average). That said, if we can grow crops under domes, then that is still v. energy efficient, so it might win out over chemistry. As for something like bamboo, it takes v. little processing...it is kind of ready for use which is another advantage.

elderflower wrote:

And what is the production per manhour of each, Robert?
People are going to be in short supply due to the expense of supporting them -until Mars is terraformed. This will be true even if Musk gets down to his dream transportation cost.
Energy is going to be relatively cheaper, whether it is nuclear fission, nuclear fusion or solar. So making polyethylene or some other artificial fibre is going to be easier for quite a long time.

louis · 2017-08-11 18:07:53

You're right about there being a lot of synergy in chemical processing then releasing oxygen - vital to the humans on Mars for life support and rocket fuel.

elderflower wrote:

Indeed Oxygen is made by crops. It is also consumed by crops when they decay (eaten by microorganisms or fungi) in the compost heap or in soil, or in human guts and faeces. You could prevent this by stacking all the waste outside to freeze dry but then you can't use it for soil improvement.
Oxygen is also a byproduct of electrolysis of water for the extraction or recovery of hydrogen for chemical feedstock.

louis · 2017-08-11 18:17:53

Another salient point in comparing the Mars and Earth economies is that the early Mars economy will be frugal. Really, we can all get by with a v. limited set of clothes, as long as we can wash them reliably after use. The equivalent of sleep-wear (light imported cotton clothing) will probably be fine for most people most of the day on Mars.

I read on the net that a T shirt weights about 135 grams, so you could probably dress someone for 0.5 Kgs in a warm life support environment on Mars. You could probably keep someone dressed for a whole year on a 3-day cycle (i.e. washing clothes every 3 days and three sets of clothes)...so for a 100 person colony that would be 150 kgs! Hardly anything at all...

I think clothes are the least of our worries. Just import them for the first 10 or 20 years.

IanM wrote:

I agree that many natural and synthetic fibers will be used for making clothes, especially before animal products such as leather and wool become readily available. I think flax will also be used. In addition to its use in linen, flax seeds can be used for food or making oil, and its stems can be used as paper for some purposes.

IanM · 2017-08-11 18:24:54

It's a bit harder to find stats about flax than cotton for some reason. Since I couldn't find any stats on the productivity of flax in making clothes, let's say that 2,400 lb of fibers are needed, just like cotton. From what I could find, flax yields range from 18-20 bushels/acre, per https://hort.purdue.edu/newcrop/afcm/flax.html. According to https://www.unc.edu/~rowlett/units/scales/bushels.html, 60 lb of flax make a bushel, so taking the low end of the yield brings 1,080 lb of flax fiber per acre. Probably flax's biggest drawback is its apparent inefficiency; back in 1930, 27,880 lb of pre-retted flax straw ultimately begat a mere 2,613 lb of usable fiber (https://www2.cs.arizona.edu/patterns/weaving/articles/lga_flax.pdf, combining hackled line and all tow fibers). Assuming no improvement in efficiency since then, this 2,400 lb would need to be gotten from 25,607 lb of raw material, grown on 23.7 acres (95,910.5 m^2).

The growing season of flax is only 100 days (http://www.libeco.com/en/about-linen/fr … linen.aspx), so that means we can have 3 crops per Earth year. As such, we can divide this area by 3 and get 7.9 acres (31,970.2 m^2). As said by RobertDyck, this is for a hypothetical colony of 100, and the area needed for a colony of 12 would be a lot lower, 0.95 acres (3,844.51 m^2) assuming that it scales linearly, which is still quite a lot higher than the corresponding amount of cotton. Perhaps we could find some purpose for the gummy byproducts of raw flax,.

louis · 2017-08-12 05:57:44

Just to get this in context, the requirement for clothes could be less than 200 kgs per annum for a colony of 100 but their food intake requirement would be about 65,700 kgs. 65,700 versus 200 - I think we can see where our main effort would be going...into food. And after food, using plants for chemicals in industrial processes or as materials themselves (eg bamboo) . I think textiles comes in at the bottom of the list, though we will undoubtedly move into that eventually.

RobertDyck · 2017-08-13 17:20:51

Moved from "Cattle"...

As I said, I expect livestock will arrive on Mars, but it'll always be expensive, and the initial Mars settlement will have to be vegan for purely practical reasons.

A few years ago finances were tight, I had to accept groceries from the local food bank. One thing was a bag of something that looked like dried split peas, but they were small and orange. I had to look up on the internet what they are. Turns out they're called red lentils, even though they're orange. Next question is what do I do with them? I discovered something called Koshari; apparently the "national dish of Egypt". It's maracroni, rice, lentils, with a spicy tomato sauce. Sometimes with garbanzo beans (aka chickpeas) sprinkled on top. I was trying to get closer to a single lady my age, so suggested this for her. She has celiac disease so has to eat a gluten-free diet, and had just became vegan. For her, I suggested replacing macaroni with gluten-free pasta. For everyone else I would suggest normal pasta because it's made with high gluten wheat flour. That's needed for nutrition.

This dish is nutritionally balanced. Lentils are legumes. All legumes are high in protein, but low in some amino acids. Rice also have protein, but also low in some amino acids. But what's scarce in one is plentiful in the other, so mixing beans with rice, or legumes with rice will give you a "complete protein". At least all essential amino acids. This dish also has pasta, high gluten wheat, which is protein with a different balance of aminos. Rice and pasta also provide starch. Cooking procedure is elaborate to increase flavour: instead of just boiling rice, dry rice is first fried in a couple table spoons of vegetable oil, then vegetable stock is added, brought to a boil then simmered. Lentils have cumin, fresh garlic, and a bay leaf. Tomato sauce is made with Egyptian spices, so you have to start with a sauce that doesn't have North American spices; I use crushed tomatoes. For the sauce, start by frying diced onion in a couple table spoons of vegetable oil, add minced garlic, Baharat spice blend, red chili flakes, and red wine vinegar. That Egyptian spice blend is: black peppercorns, cumin, coriander, cloves, cardamom, paprika, cinnamon, nutmeg. I don't have that spice blend, so mix the spice blend when I make the dish.

This dish does not try to look like something else. It has protein, starch, and vegetable oil. The oil stays in the rice and tomato sauce. I make it for myself every so often. Not often, but once in a while. For myself I use normal macaroni, and to be frugal make vegetable stock from kitchen scraps. I could link recipes if you wish. I think I already posted those links earlier in this thread [Crops]. We could grow all ingredients in greenhouses on Mars. Cinnamon, nutmeg, bay leaves and cloves come from trees, but we could grow them.

IanM · 2017-08-14 21:29:09

Regarding Quinoa, RobertDyck's post on it in the very first page of this thread notes that a 100 g serving of it has 368 calories. I'm going to assume a colony with at least two people and which is exactly evenly divided by sex, and that the average height of the men is 5'10" and that of the women is 5'5", based on data from the US Census Bureau. The average weight should be right in the middle of a healthy weight range, which given these heights according to a BMI chart is 150 lbs for the gentlemen and 130 lbs for the ladies. The Total Daily Energy Expenditure (TDEE) is the number of calories that should be consumed to maintain such a weight, which according to https://tdeecalculator.net/ is, assuming 15% body fat for the men and 22% for the women (which is fit according to https://www.builtlean.com/2010/08/03/id … ge-chart/) and that the average colonist is 25 years old and gets light exercise moving around the colony and its surroundings, 2226 calories/day for men and 1875 calories/day for women, which averages out to 2050.5 calories/person-day for a colony.

From this average an individual colonist would need 748,432.5 calories/(Earth) year, which amounts to around 2 kg of quinoa if that's all they ate (which would be a bit miserable, but for the sake of example). For a colony of 100, this means 200 kg are needed. Apparently with normal methods (let alone intensive ones) a whopping 500-900 kg of crop can be produced on 1 acre (https://www.saltspringseeds.com/pages/g … dans-scoop), so using the low end of that yield a mere 2/5 of an acre (17,424 sq ft./1,618.74 m^2) would be needed, quite a bit less if there's variety in the Martian diet. RobertDyck's colony of twelve would need even less, a cumulative 24 kg of the stuff that can be grown on 0.048 acres (2,090.88 sq ft./194.2491 m^2). My city block in Chicago has an area of 148,500 square feet or 13,500 m^2, enough land to grow enough quinoa for more than 1,000 colonists.

Oldfart1939 · 2017-08-14 21:52:29

Somehow, Ian, your numbers are not making a lot of sense to me. I calculated that a single colonist would require 203.38 kg of Quinoa per Earth year in order to survive. For a colony of 100, that amounts to 20.34 metric tonnes per year, by my calculations.

I don't really like this style of calculation; the best way of estimating the amount of food needed is simply allow 2% of body weight of the colonist per day. That's a mixture of fresh, dry rehydrated, etc.

Somewhere, you got lost in the math, cause 2 kg of Quinoa per year would be a starvation ration. They had better food than this at Dachau. Please expand on how you arrived at your numbers.

Last edited by Oldfart1939 (2017-08-15 10:54:10)

RobertDyck · 2017-08-14 22:20:56

You notice I dropped quinoa. My sister mentioned it. But the point of this discussion thread is a comprehensive list of food crops to sustain a permanent settlement. That means no food from Earth. Calculating dehydrated food etc works for a science mission, not permanent settlement.

Some older posts within this discussion thread:
Menu: Click here
Greenhouse area: Click here

You came up with a list yourself: Click here

IanM · 2017-08-14 22:26:34

Oldfart1939 wrote:

Somehow, Rob, your numbers are not making a lot of sense to me. I calculated that a single colonist would require 203.38 kg of Quinoa per Earth year in order to survive. For a colony of 100, that amounts to 20.34 metric tonnes per year, by my calculations.

Oh wow, I am greatly sorry. I mistook that it was 368 calories per 1 g, not per 100 g. It was me who made the mistake, not Rob. Thanks for correcting me. Accounting for that error means that 100 colonists would need 22-40 acres for growing quinoa, a significantly larger amount.

For 2% body weight a day for an average 140 lb colonist, that would be 2.8 lb (1.27 kg) a day,or 463.55 kg an Earth year, or 46,355 kg for the whole colony, which in turn would give 52-92 acres needed for the land. In any case a colony of 12 would have significantly less land needed, ranging from 2.64 to 11.04 acres, and more intensive farming methods per the original source might be able to up to double the yield, reducing the area further.

Oldfart1939 · 2017-08-15 10:58:36

My apologies to Rob, but it was late last night when I was writing and I was intending my reply to be aimed at Ian. The average weight per colonist that I use in calculating food requirements is the same as what the FAA uses for an "average passenger," or 170 pounds. That's a more realistic estimate than 140 pounds.

GW Johnson · 2017-08-15 12:53:18

FAA should be using closer to 200 lb than 170 lb for the "average passenger". You run a weight-and-balance calculation with realistic weights, and the results can be dramatic. I suspect there have been some serious gross weight violations.

3 of us "more typical" people hits gross with only 3/4 fuel in my 4-place Cessna 170, and I can really feel it in the climbout-out after taking off.

GW

Last edited by GW Johnson (2017-08-15 12:54:18)

Oldfart1939 · 2017-08-15 14:20:45

GW-

I fully agree with your assessment. I fly out of Casper, WY, with a Piper PA28-236 Dakota with 235 horsepower. On a cold day, I can have 680 pounds of passengers, full fuel, and 200 pounds of baggage with a normal takeoff. On a hot, high density altitude day, I would have to dump the luggage and maybe a fat passenger.

All that aside, I think that the "average American passenger" should be 200 pounds.

IanM · 2017-08-15 15:22:39

The problem with using the average weight of Americans is the fact that 70% of American adults are overweight or obese (https://www.cdc.gov/nchs/fastats/obesity-overweight.htm), and I worry that the same might happen to Martians if they adopt the same eating habits. (I myself am guilty of this; I'm 5'10", and in the summer of 2015 weighed a whopping 205 lb. I have since dropped to 180, but am still a bit pudgy.) 170 lb is around the upper limit of a healthy weight range of someone who is 5'10". In all fairness, Martians would probably be a bit taller due to lower gravity. According to space.com this would be an increase of up to 3% in microgravity, so someone who would be 5'10" on Earth would be up to 6' in a low-gravity situation (not necessarily Mars, which does have a sizeable gravity). In that case the maximum healthy weight would be 180 lb.

Oldfart1939 · 2017-08-15 17:05:20

We should be dealing with reality, not the ideal configuration of an individual. I too, am a 205 pound guy--not totally pudgy and a still fairly muscular at my 5' 10" height. When I was doing my calculations for a 550 day stay on the surface of Mars stay for early missions and a 7 man ("Person") crew, this resulted in a pretty heavy food supply. This calculated to a 7,000 kg food supply in a prepositioned location.

Last edited by Oldfart1939 (2017-08-15 17:09:05)

SpaceNut · 2017-08-15 17:27:36

At 5'4" and 140lbs I would probably not qualify as an astronaut due to hieght but then again I fit where most people can not to work on things.

RobertDyck · 2017-08-17 09:21:48

Astronaut Requirements
5'4" and 140lbs would qualify.

Last edited by RobertDyck (2017-08-18 08:29:45)

louis · 2017-08-19 19:58:57

You sound like the ideal dimensions to me! That's fighter pilot outline. But obviously age is another consideration.

SpaceNut wrote:

At 5'4" and 140lbs I would probably not qualify as an astronaut due to hieght but then again I fit where most people can not to work on things.

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