beyond exploiting nature

With that kind of thinking nobody is going to be able to live in space for any extended length of time. Just because most people are so ignorant that they will crap in their nest and destroy the living ecosystems which provide them with life support doesn't mean that everyone is stupid. If you visited me here on Faerie Hill I would show you directly how to improve the biodiversity at least a hundred-fold. My wife and I have done so and will continue to do so. We'll also continue to develop our CELSS (Closed Ecological Life Support System) test bed: the Faerie Hill ecoark which is an off-grid solar/wind powered water and waste recycling food producing home which is a live-in experiment in developing the kind of sustainable life support that is required for long term space exploration and extra-terra settlement. As long as people continue to treat nature as something which owes them a living, exploiting it's resources like they are an endless well to draw upon, they will be missing the essential point, refusing to mature as a species. Mature (symbiotic) humans recycle everything, using their tech to create materially closed systems which provide them with life support, reducing their footprint to a tiny fraction of what youthful "parasites" require to stay alive. Check this out:

CELSS TRANSFORMATIONS

CELSS (Closed Ecological Life Support System) is a "living machine" which, ideally, provides it's inhabitant(s) with 100% of their life support (organic food, fresh oxygen-rich air, clean water) by recycling the waste products generated by the inhabitant(s) and by the CELSS itself. We call that "closing the loop". As it has been said, "the devil is in the details". CELSS is relatively new in the world. Now, of course, the planet-wide life supporting biosphere it a large scale CELSS. By studying what nature does to recycle we may apply these principles on a much smaller personalized scale. It helps to design for the worst possible scenario in the harshest environments (like Mars) and then it becomes easier and simpler to build robust systems for kinder climates. So, to start, imagine we have landed on a barren planet with no air, water, or food to eat except what we brought with us. Here's what we have to work with (this can get gross):

MATERIAL INPUTS

1) HUMAN BODY: feces, urine, farts, belches, vomit, snot, spit/saliva, phlegm, sweat, tears, earwax, milk, sperm/semen, smegma, menstrual blood, blood, pus, nail clippings, hair, dead skin, water vapor, CO2, trace gasses, heat, medicine residues, and (if someone dies) dead bodies and body parts

2) PLANTS: unused biomass, garbage, plant oils, O2, CO2, ethylene and other trace gasses, water vapor

3) ANIMALS: much the same as what humans output

4) MATERIALS & PROCESSES: oils, soaps, worn out clothing (composed of natural fibers/dyes only), laundry & wash (gray) water, out-gassings (solvents/trace gasses from materials used in the CELSS shell construction and other items inside the CELSS).

That's what we have to work with in the "hermetically sealed version". Of course, on Earth or anywhere there are some useful outside resources, our task would be easier. Yet, if we design the hermetically sealed version, I`m sure, on the way to the final design, we will cover just about any condition or environment we can imagine. While we are brainstorming this "ultimate CELSS" we need to be aware of the amount of energy required to make the whole thing work. The less energy required the better. Also, technologically complex systems tend to break down faster than simple systems. We adhere to the engineering principle of KISS (Keep It Simple Stupid). We don't want to design anything which requires a lot of repairs, maintenance, or spare parts. The number of human hours spent per day keeping the system fully operational should also be considered. We're not into this to work ourselves to death. We shouldn't have to spend more than a hour or so a day doing our chores in an optimal system. Remember, we're on a planet's surface so we have gravity on our side. In space we would have to spin the whole thing to simulate gravity. For now, let's stay grounded and focused on the transformations.

The MATERIAL INPUTS listed above must be transformed into the following:

1) nutrient rich water and soil for plants, fungi, and symbiotic micro-organisms
2) CO2 and trace gas-rich air for the plants, fungi, and symbiotic micro-organisms
3) clean water for humans and animals
4) oxygen rich air with few trace gasses (ethylene, methane, carbon monoxide, and other exotics) for humans and animals
5) continuously and regularly producing organic food supply for humans and animals

Get the picture? What goes around comes around. There is a dynamic relationship between humans, animals, plants, fungi, and symbiotic micro-organisms. What we are trying to do is optimize this relationship by building containment vessels which provide optimal conditions for each of the above. We want to make everyone and everything involved very comfortable and in a state of being nurtured at all times. We also want to do this in a way which prevents pathogens from thriving. We're aiming for a high oxygen level (aerobic) conditions throughout the CELSS. Anaerobic conditions (such as found in septic systems) are to be avoided because they breed disease and poisonous gasses like hydrogen sulfide (rotten egg odor) and methane. Plants out-gas ethylene which is, at certain concentrations, a growth inhibitor for the plants. It too needs to be converted or a hermetically sealed system will die.

How large should a fully operational CELSS be? As small as possible and small is possible. Here are some optimistic figures from the CELSS life support research community:

ESTIMATED GROW SPACE REQUIRED PER PERSON
(may be stacked into multiple levels for more efficient operation)

14 m2 - Gitalson
56 m2 - Bios3
20-30 m2 - Cullingford & Schwatekopf
13-50 m2 - Bugsbee & Salisbury
56.9 m2 - Oleson & Olson
8-20 m2 - MacElroy & Averner
15-20 m2 - Eckhart
24 m2 - Hoff
15 m2 - Vasilyew

As you can see, the above figures are tiny compared to the amount of space the average human being requires for life support in both hunter/gatherer and agriculture-based civilizations. Since the Earth's "carrying capacity" is already exceeded because of the rapidly expanding human population, anything we do to reduce an individual's "footprint" (space/resource required to keep a person alive) is a step in the correct direction. Lab work (NASA Ames) has already proven that all the air, water, and food for one person can be grown in a 16' x 16' space under optimal conditions with controlled atmosphere, temperature, lighting, and nutrients. Of course this was a highly engineered "hydroponics" style system which required considerable electricity for the lighting, pumps, and climate control plus an outside source of plant nutrients. So, it cannot really be called a CELSS but it sure is an encouraging experiment. I bet we can do pretty good together too!

WATER FLOW LOOPS

Wash water and urine are mixed and channeled into grow beds, via bottom-laying perforated pipe, where various micro-organisms, fungi, and higher plants break down and convert soap oils and waste fats, food particles, dead skin, and urine into an organic food supply, fresh water (via plant transpiration and soil bed evaporation), and oxygen rich air. Human feces, fingernail and hair clippings, plant trimmings, and organic garbage are composted. The finished compost is used to fertilize the grow beds. Fresh water is condensed out of the air by a ground loop (air well) dehumidifier and the water collected goes into the clear water tank then is UV or O3 sterilized for potable use. As the microbes, fungi, and plant roots are proven to be very efficient in filtering the organics and nutrients out of water, any water which makes it from the gray water entrance point (high point of the bed) can be stored in the white water tank located at the lowest end of the grow bed. This water can be RO (reverse osmosis) or otherwise multi-filtered and the resulting clean water channeled into the clear water tank, to aquaculture tanks, and/or to animals as their drinking water. If aquaculture tanks are employed the waste water from the tanks is mixed with the gray water from the hab and channeled into the grow beds, as above. If such an aquaculture loop is employed the grow beds need to be sized to accommodate the extra waste water.

AIR FLOW LOOPS

There is a physical separation between the greenhouse portion of the CELSS and the human hab section. Stale CO2 rich air from the hab is sucked (via fan) out of the hab through the toilet seat down (with a side effect of no smells coming from the composter) through the upper composter chamber which encourages rapid oxidation and then through the lower composter chamber where composted organic materials (feces, garbage, plant clippings) are dried by the air flow. The lower chamber air flow is increased by the addition of fan-driven warm air from the dehumidifier condenser coils. The CO2 enriched air exits the composter and converges with a fan driven air stream from the greenhouse which contains not only oxygen but also the plant produced and growth inhibiting gas "ethylene". This combined air flow is channeled up through the soil/grow beds from a point just above gray water level. It is possible to configure the gray water pipe in the grow beds so that it also handles this air flow. Soil microbes and fungi in the soil strip the air flow of trace gasses (including ethylene) , helping with the breakdown of gray water (seeping upward through capillary action), and reducing oxygen in the air flow to CO2 which, in turn, leaves the surface of the grow bed and is delivered to the plant leaves which, through photosynthesis, convert the CO2 to O2. The purified greenhouse air then s split into three flows: one circulates back through the soil/grow beds (SBR: Soil Bed Reactor). Another flow goes through the cooler/condenser/dehumidifier, where it is stripped of excess moisture, into the Hab. The third air flow/loop is warm moist greenhouse air through an air well buried under the SBR, where excess heat is stored in thermal mass and moisture condensed out of the air flow, with the cooled dry air passing through the dehumidifier condenser coils and on to the lower chamber of the composter.

ANIMAL PRODUCTION LOOPS

This is where it gets complex, for several reasons. If there are animal byproducts and elimination wastes to compost in a CELSS, then there can be a loss of fixed nitrogen in the system using a fast-oxidation style composter as indicated above. In a vegan or vegetarian style CELSS this is not a problem since there is very little fixed nitrogen in the compost. Most of it enters the grow beds via the urine. On the other hand, in the case of animals, Rodale style slow composting is required in the system and the hab to greenhouse air flow as described above needs to bypass the slow process composter and head straight to the grow beds as described in the water flow paragraph. One of the side benefits of the slow compost process is that it mates well with vermiculture (worm growing) which can both provide a food source for either fish or poultry and a valuable source of plant nutrients when spread on the plant beds. Discussion is needed on whether or not poultry should be allowed to free range within the greenhouse which is good for keeping insect pests at bay but adds the potential problem of contaminating the white water which exits the gravity fed slow flow (from end to end) grow bed. If this water is RO filtered and fed to poultry, aquaculture, or other animals, it might be fine but I wouldn't channel it into the clear water tank discussed in the water flow paragraph.

GREENHOUSE CONFIGURATION

As was stated above, the greenhouse section and the hab need to be separated. Summer solar heat needs to be controlled. Evacuating the air from the greenhouse breaks the air and water flow loops and we no longer have a CELSS which supplies us with fresh air and water for drinking and washing. Excess heat and moisture can be transferred and stored in an air well and thermal mass heat storage area buried under the greenhouse, possibly the entire CELSS (including hab). We have touched on the idea of making mechanical power from the hot air via a stirling heat engine and/or electric power from solid state peltier junction thermoelectric "heat pump" chips. Both of those concepts need further investigation. It is also clear that the grow beds in the greenhouse might need to be stacked to save space, that there needs to be a built-in trellis system for climbing plants, lower growing plants need to be in the front (sun facing side), medium height plants in the center, and tall plants in the rear of the greenhouse. If aquaculture is employed some plants might be grown in floating platforms on the top of the aquaculture beds. If the greenhouse is partly buried (pit style), extreme temperatures in the greenhouse can be better moderated. If the greenhouse is constructed with a shading overhang, some of the summer heat can be avoided at the expense of slightly reducing plant photosynthesis. If light tubes are used to channel light into a fully buried greenhouse there is a photosynthesis penalty to pay as well. Photosynthesis periods can be extended through the use of auxiliary lighting with the best candidates seeming to be sulfur lighting or select spectrum (red/blue/green) LED lighting. Of course, the more electricity we consume the more power we need to make.

Intelligent, well thought-out comments and perspective are welcome!

- Terry Kok
http://www.faeriehillfarm.com

--- In spacesettlers@yahoogroups.com, Joe Strout wrote: