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Terraforming Mars seems to be less risky, as implausible as that statement might be given most other alternatives. There's already been much discussion on the topic, and the presence of settlements would likely accelerate it, to the point of there being a coherent and decisive plan for terraformation that can be followed by local underlings or robots by 2100. That being said, there's a lot of risk in the space voyage, especially if there's no steering mechanism on the ships to avoid potential collisions, or the colony ships' colonists' descendants will lose sight of the bigger picture and live permanently on the ships and never reach the Proxima b planet. Therefore I believe terraforming Mars will likely come to fruition first.
Thanks, RobertDyck. Duly noted.
I don't know too terribly much about Magnetism in general, so I might be off the mark, but according to http://hyperphysics.phy-astr.gsu.edu/hb … earth.html, Earth's magnetic field has a strength of 0.3-0.6 Gauss, which is 0.3-0.6*10^-4 Tesla. In order to minimize energy costs, and since Mars is farther away from the Sun, but also to err on the side of more, let's say that the B field should equal to 0.4*10^-4 or 4.0*10^-5 T. Now, Earth can be considered a large bar magnet for the intents and purposes of its magnetic field, but such a setup is impractical on the red planet, but as said before, I don't know that much about magnetism and so can't say anything of the setup, but am trying my best in crunching the numbers.
Now how to turn that into Ampere Turns? An Ampere Turn is the unit of Magnetomotive Force, which is the magnetic extension of Voltage (and not Current, as the name might imply). The magnetic version of Ohm's Law is as follows:
F = P*R
Where F is the Magnetomotive Force, P the Magnetic Flux (equivalent to Current, and usually denoted by the Greek Letter Phi, which is unavailable on my keyboard), and R the Magnetic Reluctance (equivalent to Resistance). All we know so far is B, which is 4.0*10^-5 T, but we can find out P in that B = P/area, which I assume is the surface area of Mars. The surface area of the Red Planet is 55.91 million square miles, which is 1.45*10^14 m^2. That and basic algebra results in P being 5,79*10^9 webers.
So the number of Ampere Turns is essentially 5.79*10^9 times whatever the magnetic reluctance is. There is an equation to derive this involving the length of the circuit and the magnetic permeability of the material it's made of. Elderflower gave a cable around the Martian equator, giving a circuit of 2.1*10^7 m. The most magnetically permeable material according to Wikipedia that produces a field at the specified B field is pure Iron, which is also easily obtainable on Mars and which has a permeability of 0.25. Applying these data, and assuming a cable with a cross-sectional area of 1 square meter, produces a magnetic reluctance of 6.79*10^13 H^-1.
All this, assuming I didn't egregiously err somewhere, provides a cable of 3.94*10^23 Ampere Turns. Assuming 1 complete turn every meter on the surface, this allows for a large cable of 1.84*10^13 Amperes, quite a substantial current.
Without such life/health extension, I would assume that the Martian population would age faster due to radiation/conditions, etc. As such, and especially since the Martian population wouldn't increase fast enough for replacement in the early years, I believe some of these techniques would be necessary. Telomere extension, from what I understand, carries as a trade-off increased risk of cancer. Treating the body as something to be repaired seems feasible, especially as attitudes towards obtaining stem cells gradually liberalize, and given the other two would be my choice right now. Epigenetics seems a bit too conjectural at the moment, but promising as well.
I will unfortunately be in school when it happens. However, I send my best wishes!
Any conductive space elevator will be a giant lightning rod. What do you think would happen to a carbon cable struck by lightning?
Nothing good, especially if it shorts out any engine keeping it up and thus causes it to collapse. Perhaps in theory there could be an insulative sheath covering the actual carbon, like the plastic coverings of electrical cords. But while such things have negligible or at least manageable weight with your household extension cord, I wonder how much it would weigh at the scale of a space elevator? If it's too heavy, that would complicate things immensely. There might already be an insulator light enough to do the job, but if there isn't, that means that there would be yet another material to be developed.
A lot of the ions could be extracted and combined for different uses, though it might get a bit complicated, especially as water soluble perchlorate is. Perhaps an organic solvent such as acetone may be used to collect perchlorate ions instead.
In any case, it is desirable to have salt-resistant varieties of different crops.
I've noticed that Martian dirt is known as salty. Is it known what exactly type of salt or salts are in the soil? If it's ideally Sodium Chloride, or even another useful salt such as Magnesium Chloride, it could theoretically be extracted from the soil and put to use on its own in addition to making the soil more friendly to these various crops. Of course, I'd have to know more about the composition of Martian regolith in order to assess it.
So the reason you haven't been able to find data on partial gravity is there isn't any.
That is quite surprising and disappointing. That and finding out ground conditions on Mars are I think the most important short-term science, as opposed to engineering, projects. Though Terraformer is right, in that we at least know somewhat how to set up such experiments properly.
If we were to use an incinerating toilet to dry feces, I would assume the high temperatures might require some more space to cool down and condense the water compared to the Russian version. That being said, I'm assuming NASA has already thought of that, and perhaps the temperatures might also quasi-pasteurize the water, making filtration slightly easier. In any case, I agree that both methods should be simultaneously tested and compared.
For electrolysis, assuming that this is a simple 2CO2 --> O2 + 2CO reaction, the Carbon Monoxide could be used for some other purpose; perhaps it could be further broken down into graphite and Oxygen, but I have a feeling that that will be a highly energetically unfavorable reaction.
Unfortunately, I could not find anything about bone growth in merely partial gravity, like on Mars, so I can't say anything about the decrease of bone calcium and the increase of urine calcium.
Here are some thoughts:
-URINE: In addition to clogging the urinary disposal systems, calcium also contributes to the formation of Kidney stones, which are by no means pleasant to deal with it, especially on somewhere such as Mars. While my gut feeling would be to somehow collect the calcium from the urine to try absorption by the bones, perhaps it would be better to prevent absorption loss in the first place. Dealing with it directly is unfortunately outside of my knowledge
-FECES: This is very risky, but also worthwhile: unlike fresh urine, which is for all intents and purposes sterile, feces is loaded with a lot of unsavory things such as E. Coli, which while belonging in the digestive system is bad in the bloodstream. I do know that people have historically dried dung for use as fuel - perhaps the water lost by such a process could be collected and purified to remove bacteria and other pathogens. As for the reality show aspect, I remember that Mars One tried raising funds by featuring their first astronauts on Television, but from I've read that plan ultimately fell through.
-ELECTROLYSIS: Perhaps the CO2 could be concentrated to make the process more efficient.
-SINK AND SHOWER: After researching it a little bit, I am surprised that having rinsing shampoo hasn't happened yet. For medium- and long-term goals, we could have a partial-G space transport instead of zero-G, which would make rinsing at least a bit easier.
This is quite an interesting topic. Perhaps it could be one of the names you listed. Perhaps it could be based on the local Geography (such as "Elysium City", "Olympus", etc.) Perhaps it might be named after a city on Earth, depending on who colonizes it; if the colonists are mostly Americans, for example, they could name it either "New New York", "New Houston", or "New Chicago", among many other things. I'm kinda partial to the last one, not only because it's my hometown, but because the settlement could be seen as a gateway to space much like Chicago was a gateway to the Wild West.
That being said, that is all my own personal opinion, and I think the settlers themselves would name it.
As far as I know, corn isn't any more efficient than potatoes on a calorie/m^2 basis, at least not in commercial farming (potatoes produce 40 tonnes per hectare, whilst corn produces 8 tonnes). Of course, that's probably nowhere near the max that's possible, even with unmodified plants.
However, isn't corn quite an energy hungry plant that requires lot's of sunlight? Whereas potatoes do well in shady areas - or under the lower insolation available at Mars...
Also fair enough - I've just been noticing that corn is one of the most fruitful of plants per acre from my calculations throughout this forum, and is likely the most efficient of the grains. We could also perhaps use both ambient light and artificial light either as a supplement or an emergency backup during a dust storm or other cover. Or also, for all plants, install mirrors as has been discussed.
150 m^2 is the square with slightly less than 12.25 m on either side. It's equivalent to slightly less than 1,614.6 sq ft., which likewise is the square produced by slightly more than 40' 2.2" on either side. For a colony of six, potatoes would take up 9,687.6 sq ft. or slightly less than 0.223 acres, and for 100 it would be 161,460 sq ft., slightly less than 3.71 acres. While there are more efficient crops than this, such as corn and legumes, neither are true substitutes for the vast array of uses of the potato, and as Terraformer implies, we could have a higher-yield crop than 10 kg/m^2.
Most Christians don't realise that when Jesus said 'love thy neighbour' he was talking about other Jews. His was a racial nationalist movement intended to expel foreign influences (specifically Roman-Greek in his day) from Judea.
Which makes the fact that Christianity has been the source of much antisemitism all the more sardonically ironic. I've heard it said that modern Pauline Christianity has as much to do with the historical Jesus as the movie Cars has to do with cars.
Back to the main point, I agree with GW that the Apollo Program, to the extent that it was simply going to and from the Moon was a dead-end route, but I think a certain shift in direction to a more settlement-based plan would have done much good. However, I don't think Hubert Humphrey would have been as pro-space as Johnson, and even then he was clobbered in the electoral college by Nixon in 1968.
Well, it's all about being over several launch windows: Even with the settlement of 6 expanding by only 12 per launch window, that's still 66 people after 11 years and 5 launch windows, and depending on when the floodgates open for second- and third-wave civilians to settle and expand the settlement, it could be significantly more.
Could a settlement of 24 build habitat and life support for 100 in just one launch window?
If I remember correctly, one launch window is ~26 months, roughly equivalent to 1.15 Martian years. If we incorporate two growing seasons into one Martian summer, I could see them supporting up to 50 for the next launch window, but I'd need some more calculations , and in any case point taken. For such expansion, however, I'd think that modularity would be key for the settlement. My apologies for any misunderstanding, I've kept assuming we're dealing with a somewhat mature settlement here, my bad. My wheat figures for a settlement of 6 and 18 still stand.
Let's see what happens with Wheat with a small settlement that starts out with 6 people and adds 12 people after every launch window. I assume that the colonists will not have kids until the settlement reaches a population of at least 100 at the earliest, thus negating any possibility of natural reproduction.
I assume that the wheat needs for the Original 6 would be imported with them for the first 6 months, which as SpaceNut said would be around 450 lb. However, afterwards they would need to grow their wheat. As I have calculated before, a colony of 100 would need 5.54 acres for their wheat per growing season; extrapolated to the 6, this would be 0.3324 acres, or 14,479.344 square feet. Each influx of 12 would add 28,958.688 square feet to this necessity. For clearer reference, 14,479.344 square feet is a square of slightly more than 120 ft by 120 ft, and 28,958.688 square feet is likewise a square of slightly more than 170 ft by 170 ft; however, the initial influx of 12 people would add to the initial 120 ft by 120 ft square 88 ft to each side, and the next addition would add slightly less than 61 ft to each side of that square, and so on, so it is entirely feasible for the colonists to overgrow to accompany potential future settlers, especially with the long shelf lives of flour that RobertDyck posted.
Quite a lot of the acres involved in food production have to deal with grains, especially wheat. The shelf-life of refined flour is 1-2 years in a chilled airtight container, which is half to a full Martian year. If we do as I propose and manage to include two growing seasons in the Martian summer, this should not be much an issue, though it does mean that any overgrowth should be used for more planting, rather than milling.
Two crops in that time would be more reasonable. Could you shorten the cold period, simulated winter, to trigger flowering? More than two crops per Martian year?
You bring up a valid point, one which could jeopardize my calculations so far, including the one I'm making right now. I personally would have two growing seasons, and alternate the fields per crop for each growing season, as a form of crop rotation. The soil would thus be enriched, and my calculations wouldn't be completely discarded lol.
Lima Beans 15 lbs, Soy Beans 30 lbs, Split Peas 15 lbs, Lentils 15 lbs, Total Legumes 75 lbs
That's an abridged count for legumes. I didn't have enough information about the "Dry beans" or "soup mix" to make any calculations. The preceding is, in any case, for a crew of 6 for 12 months. Extrapolated to a colony of 100 for 12 months, this is 500 lb Lima Beans, 1,000 lb Soy Beans, 500 lb Split Peas, and 500 lb Lentils, for a total of 2,500 lb of Legumes. From data sources aforementioned, this translates to 16.666 bushels of Lima Beans, 16.666 bushels of Soy Beans, 20 bushels of Peas. Statistics Canada pegs Lentils directly at 1,296 lb/acre (http://www.producer.com/2012/10/ranking … surprises/), leading to 0.39 acres of land devoted to their use. Experimental Quickpick peas over 1 year (http://www.purplehull.com/pdf_files/FSA-6057.pdf), had 1,019 lb/acre, which I'll round down to 1,000 for defensive pessimism. This results in 0.5 acres for their use.
As for the other legumes, Soy ranks in at 58 bu/acre (https://www.extension.iastate.edu/agdm/ … c2-20.html), thus needing 0.35 acres of land, and Lima Beans have 260 bu/acre on the pole (http://www.lsuagcenter.com/topics/lawn_garden/home_gardening/vegetables/expected-vegetable-garden-yields, w/ 130 rows/acre), thus needing 0.065 acres for their production.
This results in (a lot of) the legumes needing 1.305 acres to produce enough for 100 people; this combined with the 7.786666 acres for the grains results in the populace needing at least 9.09166 acres to have such basic food. A square mile to satisfy such needs for up to 7,039 people.
Grains:
Wheat 450 lbs, *Flour 75 lbs, Corn Meal 75 lbs, Oats 75 lbs, Rice 150 lbs, Pasta 75 lbs, Total Grains 900 lbs
That is, as SpaceNut said, required for a crew of 6 for 6 months. By arithmetic, that means a permanent settlement of 100 would need annually (Earth years, so 12 months) 15,000 lb of wheat, 2,500 lb of corn, 2,500 lb of oats, and 5,000 lb of rice. So 25,000 lb of grains total, which seems daunting.
Let's convert these into bushels. Calculations from https://www.unc.edu/~rowlett/units/scales/bushels.html beget 40 bushels (rounded up for defensive pessimism purposes) of corn in the ear, 80 bushels (ditto) of oats, and (per http://norganics.com/index-2/technical- … ht-table/), 85 bushels (ditto) of rice, and the more pessimistic http://wheatlife.org/aboutwheat.html yields 360 (ditto) bushels of wheat.
In Missouri, Corn yield has ranged from 9.3 bushels/acre in 1934 to 186 bushels/acre in 2014 (http://crops.missouri.edu/audit/corn.htm). I'm going to assume Mars has taken advantage of the Green Revolution, but not quite to Missouri's extreme; so I'll somewhat arbitrarily assign corn to 150 bushels/acre; this results in 0.26666 acres being needed for corn to feed the hundred (I personally think Corn, given such density, will be a choice crop for agriculture.). Wheat provides 65 bushels per acre, so the colony will be using 5.54 acres for their wheat. The average farm in Arkansas in 2010 raised 72.4 bushels/acre of rice (http://www.encyclopediaofarkansas.net/e … ntryID=380), so I'll assume Mars does the same, thus needing 1.18 acres of riceland. Oats have ~100 bushels/acre per http://www.coolbean.info/pdf/small_grai … _Tests.pdf, thus requiring the colony to use 0.8 acres to their uses.
This ultimately means that these colonists would have to use 7.78666 acres of farmland for their grain, 71.14% of which would be for wheat. With such data, this would mean a square mile, or 640 acres, would provide the grain needs of 8,219 people.
I know that Salmonella won't grow when freezing, I'm just concerned about when it's being cooked, that it really really has to be cooked well, more so than Beef or Pork.
According to the NIH, a 51+ male adult should take in at least 1.7 mg/day of Vitamin B6. This means the annual need of Vitamins B6 is 62.05 g. Chickpeas provide 0.2 mg of Vitamin B6 in 1 cup, or 164 grams of chickpeas (http://nutritiondata.self.com/facts/leg … cts/4326/2), thus 310,250 cups or 1.9 kilograms (4.185 lb) of chickpeas would be needed annually for our colony of 100. Large Chickpeas were at 540 lb/acre in Montana (http://www.fsa.usda.gov/FSA/newsRelease … l_166.html), leading to 7.75 * 10 ^-3 acres needed of chickpeas for the colony to get its Vitamin B6 fix.
As kinda mentioned before, there is a tradeoff of easier freezing with poultry and definitely getting salmonella without proper cooking and thus the heightened stakes and lower room for error with cooking.
No problem, and I just realized that I never quite finished my Swine post. I have work to do at the moment, but I'll get on that at my earliest convenience.