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Post by ironhold on Oct 19, 2015 20:22:57 GMT
I have not seen the film yet, I am going tomorrow and they may have covered this in the plot. But from what I understand the main character grows plants for food in the Martian soil mixed with human faeces would this really work? The Martian soil would lack the nitrogen fixing and decomposing bacteria that Earths soil naturally has in it and Human gut flora is specialised to live in the conditions found there and fill a particular niche. So would mixing this material with sterile Martian soil create a plant growing medium or could it potentially fail, the plants not having an ability to unlock the nutrients in the waste? I understand the experiment might be beyond what could be done and pose health issues but imagine several trays with plants in them growing in different mediums a control of normal soil, normal soil mixed with human waste, a Martian soil simulation, Martian soil mixed with Human waste etc. You could measure how well the plants grow in the various mediums and what happens to the Bactrial load in them. There would not be a heath issue here, since they would not have to handle the poo themselves (or at least not without wearing protective gear) and would have no intention of eating the produce. Using human waste might, however, be nixed by Discovery on taste grounds. So they'd most likely have to look at finding animal waste that is as close to human poo as possible. That or look at creating their own poo, which might be possible by drying and sterilizing poo and then adding water and bacteria. Actually, animal dung is a natural fertilizer and some places will even vend it as such. It shouldn't be too hard to find a farmer or botanist who can obtain some and help the guys get such a garden together.
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Post by the light works on Oct 19, 2015 20:40:23 GMT
There would not be a heath issue here, since they would not have to handle the poo themselves (or at least not without wearing protective gear) and would have no intention of eating the produce. Using human waste might, however, be nixed by Discovery on taste grounds. So they'd most likely have to look at finding animal waste that is as close to human poo as possible. That or look at creating their own poo, which might be possible by drying and sterilizing poo and then adding water and bacteria. Actually, animal dung is a natural fertilizer and some places will even vend it as such. It shouldn't be too hard to find a farmer or botanist who can obtain some and help the guys get such a garden together. right, the bigger problem is whether martian soil is sufficiently different from terran soil as to make a difference. some plants can grow directly in poo, though most require it to be somewhat diluted by some form of filler. (I.E. sand or clay)
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Post by Cybermortis on Oct 19, 2015 20:41:03 GMT
Dung from all species has been used as fertilizer, including human dung - although unprocessed human waste can carry health risks as pathogens can end up in the plant.
The reason for saying 'as close to human waste as possible' (assuming Discovery nixes using the real thing, which they might not do if its not actually seen in its, errm, 'raw' form) is to avoid what in this case would be viable complaints as to getting different results from not using the real thing.
This is a second viable myth, as the testing needed is very straightforward, the build is basically identical to things they have done before and could be put together using materials in the shop if not existing builds. The only objections could be overcome simply and easily. Either from the use of alternatives or careful camera work.
Actually now I think about it I wonder how NASA would intend to process human waste on a Mars mission? It is possible that the waste might be dried and sterilized anyway.
*Edit*
Soil is a mixture of organic material and small particles of rock. Martian 'soil' lacks the organic material, so is basically rock-dust. Adding organic material to create 'soil' is not really going to be any different from adding sand or grit to thick clay or compost. The particles allow for better drainage of water and aeration (important as most plants will die if their roots can't get air, which they can't get from water).
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Post by the light works on Oct 19, 2015 20:53:43 GMT
Dung from all species has been used as fertilizer, including human dung - although unprocessed human waste can carry health risks as pathogens can end up in the plant. The reason for saying 'as close to human waste as possible' (assuming Discovery nixes using the real thing, which they might not do if its not actually seen in its, errm, 'raw' form) is to avoid what in this case would be viable complaints as to getting different results from not using the real thing. This is a second viable myth, as the testing needed is very straightforward, the build is basically identical to things they have done before and could be put together using materials in the shop if not existing builds. The only objections could be overcome simply and easily. Either from the use of alternatives or careful camera work. Actually now I think about it I wonder how NASA would intend to process human waste on a Mars mission? It is possible that the waste might be dried and sterilized anyway. *Edit* Soil is a mixture of organic material and small particles of rock. Martian 'soil' lacks the organic material, so is basically rock-dust. Adding organic material to create 'soil' is not really going to be any different from adding sand or grit to thick clay or compost. The particles allow for better drainage of water and aeration (important as most plants will die if their roots can't get air, which they can't get from water). the key is whether their rock dust is sufficiently different from our rock dust as to cause a problem.
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Post by mrfatso on Oct 20, 2015 6:24:38 GMT
The one difference between our soil and Martian soil that might make a difference is the lack of a whole host of organisms that break down the dung and enable plants to access the nutrients that they need to grow.
Yes animal and human dung is used on this planet as a fertiliser but that process relies on the ecosystem that exists on our planets surface to enable the release of the chemical building blocks in that dung. Would the plants without the existence of those these bacteria and other organisms be able to use dung as a fertiliser or would the dung decompose in such a way as to lock them in?
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Post by silverdragon on Oct 20, 2015 8:30:57 GMT
I take it that would be in the bio-sphere-tent-thing?...
Complete fail if its outside the enclosure?... Plants need Oxygen to grow, so if this is "Outside", not the right atmosphere.... Yeah the pass out more than they use, once grown, but in the growing, they need Oxygen..... Not that much, but they do need it. Especially at night when they aint photo-synthesizing. Its "trace" amounts, but they do need it. Or is my plantology in the wrong?...
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Post by silverdragon on Oct 20, 2015 8:36:38 GMT
I know a farm in UK that is doing soil free vegetables in floating pads over water. From a FISH POND.
The feed the fish, the water is recycled through the hydroponics, the plants "eat" the fish waste, and the water goes back to the pond through normal filtering.
Therefore, animal/fish waste is enough to feed plants....
So why cant Human waste that eat those plants be just as good?...
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Post by Cybermortis on Oct 20, 2015 10:04:12 GMT
Part of that ecosystem would be there, as the bacteria needed exist in the human digestive system and on skin. There is also likely to be bacteria inside the habitat, either bacteria that came directly from earth when the structure was constructed or came from the crew when they were living there. The principle nutrient plants can't get directly is nitrogen, but that could be provided by urine - as could other nutrients. (In the context of the myth health risks would be besides the point, as this is a survival situation and the waste is only coming from one person). news.bbc.co.uk/1/hi/sci/tech/7477310.stmShort answer, depending on where you take the 'soil' its not that different to Earth soil (minus the organic components) and would be a very good growing medium. I'm actually guessing that the scene in the book/film most likely came after the author saw this report.
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Post by the light works on Oct 20, 2015 14:40:08 GMT
Part of that ecosystem would be there, as the bacteria needed exist in the human digestive system and on skin. There is also likely to be bacteria inside the habitat, either bacteria that came directly from earth when the structure was constructed or came from the crew when they were living there. The principle nutrient plants can't get directly is nitrogen, but that could be provided by urine - as could other nutrients. (In the context of the myth health risks would be besides the point, as this is a survival situation and the waste is only coming from one person). news.bbc.co.uk/1/hi/sci/tech/7477310.stmShort answer, depending on where you take the 'soil' its not that different to Earth soil (minus the organic components) and would be a very good growing medium. I'm actually guessing that the scene in the book/film most likely came after the author saw this report. hard to say if the author saw the report or not, unless of course, the author comments on it. but even on earth we have various soils that are more or less hospitable to plants, based on the fact that plants also leach minerals out of the soil, and it is the soil's mineral content that gives such characteristics as alkalinity. so at this point I would say WE know it is plausible, but it would still be an interesting TV topic.
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Post by rmc on Oct 20, 2015 17:48:04 GMT
Just as a test, couldn't a person take some bleached sand, add freeze-dried human feces, some seeds and then water it? If that ended up growing a plant, wouldn't that be an argument that whatever Mars's soil is like, adding feces, even human feces that has been space-prepped, could grow something?
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Post by Cybermortis on Oct 20, 2015 18:50:20 GMT
In Order;
The author mentioned during his interview with Adam that he'd done research into the science and technology needed for a Mars mission. This would make it likely that he would have run across this report, as it would have been available long before he started writing.
A lot would depend on what a Mars mission would do with human waste. On the moon missions it was dumped overboard, but on a Mars flight with a minimum of three years in space (a year and a half there, year and a half back) this wouldn't be realistic. Urine could and would be recycled into fresh water, and it is also possible that hydroponics might be used to help save mass in regards food storage. What I'm less clear about is what they would do with solid waste. My best guess is that it too would be looked at for recycling, but it would need to be sterilized (probably with UV lights).
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Post by the light works on Oct 21, 2015 3:09:08 GMT
In Order; The author mentioned during his interview with Adam that he'd done research into the science and technology needed for a Mars mission. This would make it likely that he would have run across this report, as it would have been available long before he started writing. A lot would depend on what a Mars mission would do with human waste. On the moon missions it was dumped overboard, but on a Mars flight with a minimum of three years in space (a year and a half there, year and a half back) this wouldn't be realistic. Urine could and would be recycled into fresh water, and it is also possible that hydroponics might be used to help save mass in regards food storage. What I'm less clear about is what they would do with solid waste. My best guess is that it too would be looked at for recycling, but it would need to be sterilized (probably with UV lights). that would seem to count as commenting on it.
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Post by silverdragon on Oct 21, 2015 7:56:01 GMT
I have tried something like the above, but not exactly the same... I have a UV filter on my pond, it washes the water going into the filters with a strong source of UV light that does a sterilization thing on the "green water" plant matter of pond scum blanket weed type stuff... I used it to clean up the fish waste, as I intended to use it for fertilizer, and wanted it clean of any bacteria?.. I cleaned the water than flushed a sand/soil/water "mud" through the system to sterilise the soil as well, to get a clean soil that I knew would be an indication as to if the idea worked. Having a UV source that is a sterilizer works for me. UV sterilizers are a big part of Pond management that are a MUST if you wish to be chemical free. Do some internet searching for pond UV filters, you should work out that about 8watts per 1,000 gallons is "about right", I only use 15 watts on my 4,000 gallon pond, and only for short periods when there is a lot of green water, because I have other things in my filtration system to help. Like Plants., I have reed beds etc... The fish waste was fed as an experiment to some young plants, that do not like too much water. I now use pond water to water many of my plants, as the experiment works. This is before I knew of the hydroponics "farm" I posted earlier... Therefore, I suspect that a sterile soil with any form of animal waste would "Work", as its not the soil that matters, its the nutrients in the waste.I would suggest that too strong nutrients may be detrimental..... That why Fish waste in hydroponics use lots of water and animal faeces in say manure are "spread out" over large area's of fields. I do know that over-fertilising Roses can be bad. I would also say that you dont necessarily need a strong UV sterilisation to grow plants. Maybe to treat them before consumption, but not to grow them.
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Post by rmc on Oct 21, 2015 11:58:13 GMT
In the questionable source, Wikipedia, there is some sort of definition of Mars's regolith. They also make the statement that, "The sand is believed to move only slowly in the martian winds due to the very low density of the atmosphere in the present epoch." Meaning, as far as 100 mph wind storms, there is the belief that this fast-moving thin mass of basically CO2 cannot impart much speed to the loose regolith, no matter how fine. I don't necessarilly believe Wikipedia's statement here, but it is in print.
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Post by the light works on Oct 21, 2015 14:19:44 GMT
I have tried something like the above, but not exactly the same... I have a UV filter on my pond, it washes the water going into the filters with a strong source of UV light that does a sterilization thing on the "green water" plant matter of pond scum blanket weed type stuff... I used it to clean up the fish waste, as I intended to use it for fertilizer, and wanted it clean of any bacteria?.. I cleaned the water than flushed a sand/soil/water "mud" through the system to sterilise the soil as well, to get a clean soil that I knew would be an indication as to if the idea worked. Having a UV source that is a sterilizer works for me. UV sterilizers are a big part of Pond management that are a MUST if you wish to be chemical free. Do some internet searching for pond UV filters, you should work out that about 8watts per 1,000 gallons is "about right", I only use 15 watts on my 4,000 gallon pond, and only for short periods when there is a lot of green water, because I have other things in my filtration system to help. Like Plants., I have reed beds etc... The fish waste was fed as an experiment to some young plants, that do not like too much water. I now use pond water to water many of my plants, as the experiment works. This is before I knew of the hydroponics "farm" I posted earlier... Therefore, I suspect that a sterile soil with any form of animal waste would "Work", as its not the soil that matters, its the nutrients in the waste.I would suggest that too strong nutrients may be detrimental..... That why Fish waste in hydroponics use lots of water and animal faeces in say manure are "spread out" over large area's of fields. I do know that over-fertilising Roses can be bad. I would also say that you dont necessarily need a strong UV sterilisation to grow plants. Maybe to treat them before consumption, but not to grow them. as I said, above, the mineral content of the soil is a factor, as some minerals would be detrimental to the plants, and high concentration of others would change from beneficial to detrimental.
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Post by mrfatso on Oct 21, 2015 17:33:24 GMT
In Order; The author mentioned during his interview with Adam that he'd done research into the science and technology needed for a Mars mission. This would make it likely that he would have run across this report, as it would have been available long before he started writing. A lot would depend on what a Mars mission would do with human waste. On the moon missions it was dumped overboard, but on a Mars flight with a minimum of three years in space (a year and a half there, year and a half back) this wouldn't be realistic. Urine could and would be recycled into fresh water, and it is also possible that hydroponics might be used to help save mass in regards food storage. What I'm less clear about is what they would do with solid waste. My best guess is that it too would be looked at for recycling, but it would need to be sterilized (probably with UV lights). that would seem to count as commenting on it. From watching the film yesterday I can say the faeces appeared to have been dried and sterilised, placed into individual packets labelled with each mission members name. This is presumably to allow later analysis by space medicine experts later on . Mark the lead character later rehydrate it to make it usable. I still question if he would have the correct bacteria needed, yes our bodies and guts contain certain types but they are not the automatically the correct ones. Another interesting idea would be to recreate the system he used to create water for his plants. He cracked hydrazine rocket fuel, to create hydrogen and oxygen, and if I recall the dialogue correctly burnt this over an iridium catalyst to make water. Would this work and create enough water? And as he says knowingly in the film " Nothing has ever gone wrong when you burn Hydrogen" ?
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Post by Cybermortis on Oct 21, 2015 17:40:18 GMT
I *think* this was a scene that the author noted got the chemistry sort of correct. Meaning that yes, the chemical reaction would produce water...unfortunately its also an exothermic reaction that should have produced enough heat to incinerate everything within the structure. (I seem to recall one of the readers of the online version did the maths on this.)
So this is testable, and would in fact give two tests for one myth both of which would be simple enough with fairly basic safety precautions.
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Post by silverdragon on Oct 22, 2015 4:47:51 GMT
In the questionable source, Wikipedia, there is some sort of definition of Mars's regolith. They also make the statement that, "The sand is believed to move only slowly in the martian winds due to the very low density of the atmosphere in the present epoch." Meaning, as far as 100 mph wind storms, there is the belief that this fast-moving thin mass of basically CO2 cannot impart much speed to the loose regolith, no matter how fine. I don't necessarilly believe Wikipedia's statement here, but it is in print. A Fine sceptical mind in operation there.... Wiki is only as good as its last article, and then only as good as the knowledge of the author of that article, and if they dont know for sure.... As far as I can find, we are the only people on the planet at this time "In print" discussing this problem on the web?... more than that, we may be the only people "About to test". Unless anyone else knows better?... and yes, I did do a search.
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Post by silverdragon on Oct 22, 2015 4:58:13 GMT
Going back a century or two, to the "Big house" estates in the UK, that didnt have sewers at that time, the waste from the houses was used as fertilisers, after first being added to the compost. I remember one old gardener stating that Human waste was good.... "That stuff will grow tomato's as big as yer fist". His name was Bill Sowerbutts, used to live in a small village in Manchester, long time panellist on Gardeners Question time, knew his stuff...
This is of course easy to test. Can the MB's use a sterile soil and mix it with Human Waste, then plant seedlings, to see what comes up.
It is suggested that proper "Composting" be done first, to kill off the unwanted bacteria or organisms.
But I do believe the UV steriliser could work here to speed that up?.. Again the Internet has many articles on this, on how Human waste is used in some places.
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Post by the light works on Feb 14, 2016 4:20:49 GMT
The movie finally came to visit, and as has become my habit, I looked up the trivia on IMDB. one thing mentioned was that the martian regolith sampled, DOES have a component that is detrimental to the plants, so he would have to get that out. however, it would be possible.
it was also mentioned that with what we have learned since the movie finished filming, all he needed to do to get water was warm up martian regolith and the water would evaporate out of it.
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