Mars more food or more food?

[thereiwas]

I don't think we need that much thrust to send people to the moon. As I said before, you send most of what they need on ahead and make sure it is in place and operational first.

 

[JonClarke]

<i>An option for early waste recycling and other garbage is to just store it as frozen waste on Mars, then recycle it at a later date. This is similar to the "poop bags" that Apollo used, except that you would save it. Waste could be stored on top of early Habs as shielding. </i><br /><br />People produce 0.16 kg of soild waste (faeces) and 2.5 kg of brine (after water recycling), 2.66 kg in total PP per day. <br /><br />Feasible I suggest for short stay (<60 days), but not for long stay (600 days). For 4 person missions, that is 638.4 kg and 6284 kg. <br /><br />It does pile up you know! <img src="/images/icons/smile.gif" /><br /><br />Incineration technology is very simple and reliable in contrast. In principle water can be recovered from the waste gas stream much easier than from brine and solid waste. The sterile ash can either be dumped or stored for reuse in biological life support when that arrives.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[j05h]

Incineration makes sense after reasonable water reclamation. Ash and other waste should be used as fertilizer later. Are you thinking greenhouses full of crops as "biological" life support? Or more along the lines of a "chlorella reactor" using spirolina or similar?<br /><br />Waste definitely adds up, but is very useful if it's used right.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[JonClarke]

reclaiming drinkable water from balack water (human waste) is very difficult because of the safety issues involved. It's also a very small proportion of the water used, which mostly ends up as gray water or in the atmosphere, where it can be fairly easily recovered. From memory nearly half the physiological water is lost to the atmosphere as sweat or from the lungs, depending on temperature, humdity and physical activity. <br /><br />condensing water from a incinterator stream is probably the easiest and safest way to do it, as it is sterile, although it would need filtering and perhaps deionizing because of other gas components that would be trapped. It might lot be worth the trouble to get another 5% efficiency in recovery.<br /><br />I have only done a quick look at biological life support. The small ones to me they seem very complex and bulky, and of uncertain reliability. <br /><br />One we start food production on Mars then it seems obvious to move to biological life support. But we have to remember that the air and water recycling part of the system is not the food production part. Otherwise you will eat your life support system. <img src="/images/icons/smile.gif" /> Parks and gardens and indoor plants will be a big part of a martian settlement I suspect<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[j05h]

Black water can stay with the solid waste and be used in another manner, either in low-order crops (perhaps as feed for LS biology?), as slag or feedstock for a product (shielding bricks or such). If we are talking uncontained usage, human waste could serve as a fertilizer for early lichen on the surface.<br /><br />Here's my take on Mars bases: locally procured water has to be plentiful for a base to work. We could "brute force" it and bring all the water or H for a short expedition. To make long-term base operations work, local water has to be procured.<br /><br />Check out 'Living Machines' built by Living Designs, if you have time. Systems like this can input sewage and output food-fish, plants and irrigation water. Their work has been inspirational in my understanding of constructed biological systems. <br /><br />On a large enough scale, the interior of Mars habitats would be very park or pond-like if built around biologics. At that scale it becomes a real ecosystem where food, atmosphere and (some) waste recycling are all part of one system. On the early base or expedition scale, it will probably be separate modules: greenhouse, water recycling and solid waste processor (outputs water, methane and fertilizer), ECLLS module (processes atmosphere via bacteria), BA-330s etc <br /><br />Eating your life support system makes sense only when the food is a byproduct. This could be as fish & shellfish, crops, small animals like rabbits and chickens. Many of these can create positive feed back together. If it is possible to grow lichen on the surface it could be used as fodder and compost inside. This is more about homesteading and settling than exploring, and assumes a sterile or non-hostile Mars ecology.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[thereiwas]

I dusted off my high school chemistry, did some research and came up with how much water can be disassociated into H2 and O2 with a given amount of electricity.<br /><br />A NASA study for the "Mars Polar Scout" project came up with an average power input of 250W from a 1m by 8m vertical solar panel, located at 82 degrees north. Should be plenty of ice there. Taking their planned 28 volt buss voltage that gives 8.9 amps, or 8.9 Coulombs per second. It takes 48,200 C to electrolyze one mole of H2O (18g), or 2677 kC per kg. With 8.9C/s available we get a rate of 3.48 days to process 1 kg of H2O. Not very fast. Let it run for 2 years and you get 209 kg of water processed, which turns into about 23 kg H2 and 185 kg O2.<br /><br />But that is assuming the reaction actually ran that fast - careful choice of electrode material is necessary. Salt in the water, or an acid or base, speeds things up considerably over distilled water, so at least there is an advantage there.<br /><br />But this is starting with water. Melting the extremely cold ice into water is also going to take quite a lot of energy. Also to keep the whole aparatus from freezing solid. (Peak daytime temps at 82 deg north is -15C.)<br /><br />I'd say use nuclear power.

 

[JonClarke]

The Mars Society's Mars Desert Research Station has had a "Living Machine' for at least four years. It has caused endless trouble. But at the moment it is working reasonably well. It recirculates black water to grey water standard, which is used for toilet flushing and plant growth experiments. But it's not safe to eat the food grown in it and you have to have a good wash before you go back in the rest of the facility.<br /><br />Don't get me wrong, this is the way to go for Mars settlement. But it does take a lot of work, mass, power, and volume to turn black water into potable water. It's not as easy as it sounds. But it can be done. The Russian Bios expriments were probably largest scale demonstration of 100% closure. <br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[billslugg]

Jon<br />Do you think the danger with food grown in black water is due to virus/bacteria moving through the roots/stems and into the fruit? Or is it a simply splashing?<br /><br /><br /> <div class="Discussion_UserSignature"> <p> </p><p> </p> </div>

 

[JonClarke]

I think is a combination of both.<br /><br />the solution is to isolate water treatment into stages - black water to intermediate water then intermediate water to potable water. <br /><br />You can ensure safety by physical separation of each stage, slow reaction times to ensure neutralisation of pathogens, water sterilisation before human consumption, fail safe design, back ups and reserves, and constant monitoring.<br /><br />Grey to potable water is much easier to do, as there are few if any pathogens and toxins involved.<br /><br />Thats my understanding anyway!<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[billslugg]

I understand. It is tough though. I did project work on the first tertiary treatment plant for sulfite pulp mill waste (Mehoopany, PA, early 70's) . Those guys had it rough. They would be putting clear, cool, low BOD effluent into the river for months on end, and then the plant would "upset". Filamentous organisms would take over and everything would go south. The bad thing about being a service organization is that you can meet the needs of the production plant (ie: break even) or you can screw things up (lose). No win. <div class="Discussion_UserSignature"> <p> </p><p> </p> </div>

 

[JonClarke]

The city I live in recently decided to fully recycle the sewerage. needless to say there has been great debate. people are concerned about what happens not when all goes to plan, but when it doesn't. <br /><br />Such issues would be life and death on Mars. You would need sufficient reserve capacity and storage to allow for down time. It all points towards a lot of volume and power. The Russian Bios-3 facility needed 400 kW to support three people.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>