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#126 2014-10-18 12:16:30

Void
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Registered: 2011-12-29
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Re: Greenhouse - hydroponics vs soil

I was not thinking about that radiation protection feature.  Sounds good.


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#127 2014-10-18 14:20:03

RobertDyck
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Re: Greenhouse - hydroponics vs soil

Thermal insulation is better with a gas than liquid. The liquid tends to conduct heat. Foam such as aerogel has lots of tiny bubbles, so lots of transition from solid to gas, and vice versa. That transition slows heat transfer; that's what provides the insulation. The problem is how to make it transparent. Change in optical index acts as a lens or prism, and lots of tiny surfaces cause such chaos that the result looks like white translucent. To keep it transparent, either ensure the solid is the same optical index as gas, so no optical effect. But that is practically impossible. There is a liquid that has the same optical index as a transparent plastic, making the liquid/solid transition invisible. However, again, liquid conducts heat a hell of a lot more than gas. And I don't know any solid that has the same optical index as a gas. Or the other solution: ensure all transitions are parallel planes. That acts as a window. Parallel planes means a multi-pane window. One method used for high efficiency windows in Canada: outer and inner panes are glass, but between there is nothing but plastic film pulled tight. Manufacturers use heat-shrink plastic film to ensure the plastic has no wrinkles.

I just suggested an idea that other Mars Society members have suggested before me: two layers of film. Pressure will hold it in place, so no need for any support rubs or any other structure. In fact, you want hold-down straps to squish it into a low, wide oval. You don't need a roof higher than ceiling height, but wider gives more room for plants. And there is some wind on Mars, so just as tent pegs hold ropes for a tent on Earth, these straps will hold an inflatable greenhouse on Mars. To do this with two layers of film, fill the gap with more pressure than greenhouse interior, but less than Mars ambient. That lets pressure hold both films in place. It can be used for safety as well: if gap pressure drops then you have a leak in the outer film. Increase in pressure indicates a leak in the inner film.

Other designs have been proposed. For example, I have suggested glass is easier to manufacture In-Situ on Mars than fluoropolymers. And glass would withstand dust/sand storms better than plastic film.

One argument we had in the Mars Homestead Project, phase 1, was greenhouse design. I argued strenuously for ambient light greenhouses. A couple others argued for buried greenhouses with artificial light. The reason was radiation. I pointed out plants can withstand more radiation than humans, and Mars surface has half the radiation of ISS. And that's on average; Mars atmosphere blocks heavy ion galactic cosmic radiation, but not proton or light ion radiation. Metalized polymer film, glass windows, or even a spacesuit will block UV, X-Rays, beta, and alpha radiation. All that's left is proton, light ion, and a medium ion is about half blocked by Mars atmosphere. Of course gamma also gets through. The best shielding for that piles of regolith, ideally 2 metre depth or greater. That can be enhanced by soaking the regolith with water and letting it freeze; effectively permafrost. A coronal mass ejection from the Sun could blast Mars with lethal radiation. Burying the habitat would provide protection for settlers. Notice the Hillside Settlement had windows for apartments, but all common spaces were well buried. A coronal mass ejection could kill all plants in an ambient light greenhouse, so I argued for a seed bank in the buried habitat.

My concern was that an ambient light greenhouse is the only life support system that will operate with complete power failure. With anything else, the power generator is a single point of failure. Furthermore, ambient light means power can be used for other things, such as In-Situ Resource Utilization. Artificial light would be needed during a major dust storm, but that means no ISRU work during the storm.

Oil filled windows are an interesting alternative. It provides radiation shielding while still using ambient light at the same time.

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#128 2014-10-23 08:13:45

Void
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Re: Greenhouse - hydroponics vs soil

Your ideas seem good.

Our objectives are different but not in conflict.

You are trying to provide a environment which will provide generalized more conventional agriculture.

I have been trying to find a minimal environment to grow a bulk or bulk crops of a value similar to hay for instance.

Plankton tolerant of low temperatures 32 degrees fresh water, would not require much Oil bag counter pressure above them.  Maybe 1 foot ~10 mb + ambient of +5.5 mb = ~15.5 mb?

If you use salt water, you can lower the temperature and the pressure, but the salt would be corrosive, and as you have pointed out their is value in having a significant oil layer above the water bag.

Artic fresh water pond plants would be one option.  However to be useful, they will have to tolerate low temperatures, which I think is likely, but also significantly low pressures.  For instance 2 feet of oil bag above 32-39 degree fresh water would be about ~20 mb  + about ~5.5 mb ambient pressure = ~25.5 mb counter pressure.  Of course the water bag itself should be able to hold a differential internal pressure.  But minimizing requirements would make the system more stable.
I don't know if Arctic pond plants could be adapted to such low pressures.

The low pressures would be why you might want to have the suit I previously indicated.  That coupled with a vertical drop off going down as much as 33 feet would allow you to have a barometric airlock system for the suit.  However normal airlock methods where the suit docks to an airlock should work OK.

For higher temperature plants Elodea for instance you would want an oil counter pressure of 7 feet, I think ~70 mb.  But in that case you could have water temperatures that were not as hostile to the human in the suit.  They would sill need pressure protection.

Sorry I did not do the metric conversions. I have limited time.

For the above, I am presuming that the oil will have a specific gravity close to that of fresh water.

One thing to think about is that by the time there are people on Mars, it should be possible to break down "Hay" like plant products into sugars and fuels.

One thing that has also occurred to me is that if you have an oil with Paraffin in it, in cold temperatures the Paraffin may gel, making the window translucent instead of transparent.  This could be a benefit to block the exit of heat at night.  A night shade.

In the case of the apparatus I have suggested, in the morning sunshine, then you might not get all the light through the window, but as soon as the ambient environment warms up, the heat from the water bag below and the sunshine should cause the Paraffin to be absorbed back into the oil, and so become more transparent again.  It may be a net benefit.

Last edited by Void (2014-10-23 08:23:00)


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#129 2014-11-25 11:58:27

Void
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Re: Greenhouse - hydroponics vs soil

http://phys.org/news/2014-11-sawdust-gasoline.html

This is why I would like to find a rugged plant with Cellulose and a very low pressure greenhouse that can go together.

From the breakdown of cellulose can come fuel, plastics and food.

From the Mars Society?
http://www.google.com/url?sa=t&rct=j&q= … vLuNeVWDBw

Our calculations show that a 5 x 20 m greenhouse constructed out of reinforced flexible UV-resistant plastic can support an internal pressure of 35-75 mb (Fig.1).........................................

3. Suitable Plants

After determining that the design potential for low-pressure greenhouses exists, the most pressing question then remains: Can plants (especially agriculturally useful plants) grow in such a reduced atmosphere?

Our experiments with seedlings in a water-saturated, 50 mb CO2 atmosphere lead us to conclude that the answer is yes. Even such relatively tender varieties as radishes, alfalfa and mung beans show surprising adaptability to such an exotic environment.

And of course I have mentioned water filled greenhouses with water or oil filled bags above to apply counter pressure, and a special diving/spacesuit for such an environment.

Convincing underwater plants to include cellulose would be a desired trick if possible.

Last edited by Void (2014-11-25 12:13:10)


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#130 2015-06-30 19:20:35

SpaceNut
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Re: Greenhouse - hydroponics vs soil

We have been busy figuring out how to get the mass of propellant down and other featuress that would make a mission to Mars possible and here is another research area.

'Smart' LED Farming Could Make Space Veggies Viable

dnews-files-2015-06-led-lettuce-670x440-150630-jpg.jpg

“(Conventional) lighting was taking about 90 percent of the energy demand,” added Poulet. “You’d need a nuclear reactor to feed a crew of four people on a regular basis with plants grown under traditional electric lights.”

Through experiments on lettuce, Mitchell and Poulet found that high-intensity LEDs were smaller and longer lasting than conventional light sources and they emit negligible radiant heat. In other words, the light-generating components of a space greenhouse can be tiny and positioned extremely close to the photosynthesizing plants without scorching the leaves.

Targeting hydroponically grown leaf lettuce with red and blue LEDs saves a significant amount of energy compared with traditional lighting..

Space exploration is a resource-intensive endeavor, especially if you throw humans into the mix. Everything from life support to water supply to waste disposal need to be carefully controlled when supporting astronauts in orbit. The International Space Station, for example, is a grand experiment into how to keep astronauts alive and healthy in a microgravity environment. But the orbiting outpost is only a couple of hundred miles from the Earth’s surface, so supplies can be shipped from Earth -- creating a self-supporting biosphere isn't a possibility.

Supporting long-duration spaceflight beyond Earth orbit, however, is an entirely different challenge

“Everything on Earth is ultimately driven by sunlight and photosynthesis,” said Cary Mitchell, professor of horticulture at Purdue University in a press release. “The question is how we can replicate that in space.”

Most interestingly, with LEDs, the wavelength of light they emit can be carefully tuned and the researchers have worked out exactly what light the lettuce needs to thrive. Using red and blue LEDs, they found that to optimize photosynthesis, a 95:5 ratio of red and blue LEDs are required.

“Instead of the minimum 4-foot (120 centimeters) separation we had between conventional lamps and lettuce, we could get LEDs as close as 4 centimeters (1.6 inches) away from the leaves

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#131 2016-12-30 10:58:13

SpaceNut
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Re: Greenhouse - hydroponics vs soil

Lake Matthew Team - Cole wrote:
Oldfart1939 wrote:

I have issues with the concept of using hydroponics. It's certainly possible for certain varieties of plants, but totally unfeasible for grain crops such as wheat, barley, oats, rye...etc. It's very difficult to harvest from hydroponic containers, at least in any quantity.

"Containers"?  That's a misapprehension.  The LMT scheme grows half-acre plots.  No containers.  It's only hydroponic because it uses inert bedding substrate.  There's no obvious need for a complex soil.  Or is there?


Substrate material is Rock wool...  https://en.wikipedia.org/wiki/Mineral_wool

Stone Wool as a Growing Substrate for Hydroponic Systems

How to Use Rockwool in Hydroponic Gardening

Special Considerations When Using Rockwool For Hydroponics

This added material does add to the difficultity of a mission to Mars when we are currently Mass limit to the surface.

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#132 2016-12-30 12:15:36

Oldfart1939
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Re: Greenhouse - hydroponics vs soil

Hydroponics could serve for crops such as Bush variety squashes (Zucchini, Yellow Crookneck), Tomatoes, Lettuce, Bush Beans, etc. but would be a real pain to use for grain crop production on a large scale. As Spacenut has indicated above, there are several mass limitations involved, rendering hydroponics as an interesting impracticality.

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#133 2016-12-30 18:51:06

SpaceNut
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Re: Greenhouse - hydroponics vs soil

I do feel that hydroponic food growth will win in the end as we are able to transport larger payload mass to mars but initially we are look to just supplement what we do bring. If cargo preload is possible around a beaconed landing site then we can just jump right to doing so earlier rather than later....

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#134 2016-12-30 20:16:22

Void
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Re: Greenhouse - hydroponics vs soil

I generally would not intrude here, but I did have an experience with growing tomatoes in plastic translucent milk jugs, largely filled with mixture of perhaps 90% Styrofoam packing beads, and soil.  I hung them on a fence, and of course sunlight did partially penetrate the jugs.
I did use chemical plant food from a bottle.  The Styrofoam/soil was heavily wetted, but some of it was air filled on the top.

What I can say is the tomatoes grew fine, to excellent.  The only down side was if I traveled somewhere, the water would tend to be exhausted and the plants would start to wilt.

I do not consider this information to be superior to what the really experienced farmers/gardeners here have to offer.  Just offering it.

The point is you would not need fancy process control watering equipment, but could simply have a jug, and some fertilizer, perhaps largely of processed urine, feces, and perhaps that would work at the start for some plants, providing some calories and nutrition.

https://en.wikipedia.org/wiki/Polystyrene
The ability to manufacture Polystyrene might be fairly useful for that purpose and for many other purposes.  Particularly if good soil is hard to manufacture.
Quote:

Polystyrene (PS) /ˌpɒliˈstaɪriːn/ is a synthetic aromatic polymer made from the monomer styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and rather brittle. It is an inexpensive resin per unit weight. It is a rather poor barrier to oxygen and water vapor and has a relatively low melting point.[4] Polystyrene is one of the most widely used plastics, the scale of its production being several million tonnes per year.[5] Polystyrene can be naturally transparent, but can be colored with colorants. Uses include protective packaging (such as packing peanuts and CD and DVD cases), containers (such as "clamshells"), lids, bottles, trays, tumblers, and disposable cutlery.[4]
As a thermoplastic polymer, polystyrene is in a solid (glassy) state at room temperature but flows if heated above about 100 °C, its glass transition temperature. It becomes rigid again when cooled. This temperature behavior is exploited for extrusion (as in Styrofoam) and also for molding and vacuum forming, since it can be cast into molds with fine detail.

And if needed, my sincerest apologies if this annoys.  (Particularly to the Old Fart smile ).

Last edited by Void (2016-12-30 20:21:58)


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#135 2016-12-30 21:40:23

Lake Matthew Team - Cole
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Re: Greenhouse - hydroponics vs soil

Coals to Newcastle, Basalt to Mars

SpaceNut wrote:
Lake Matthew Team - Cole wrote:
Oldfart1939 wrote:

I have issues with the concept of using hydroponics. It's certainly possible for certain varieties of plants, but totally unfeasible for grain crops such as wheat, barley, oats, rye...etc. It's very difficult to harvest from hydroponic containers, at least in any quantity.

"Containers"?  That's a misapprehension.  The LMT scheme grows half-acre plots.  No containers.  It's only hydroponic because it uses inert bedding substrate.  There's no obvious need for a complex soil.  Or is there?

Stone Wool as a Growing Substrate for Hydroponic Systems

This added material does add to the difficultity of a mission to Mars when we are currently Mass limit to the surface.

No, stone wool is just granulated basalt fibers, no better than sand (i.e., granulated basalt) for this purpose.  And the cost!  Stone wool substrate for a single acre would fill the better part of a cargo ITS. 

For no reason.

Last edited by Lake Matthew Team - Cole (2016-12-30 22:04:23)

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#136 2016-12-30 21:56:43

Lake Matthew Team - Cole
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Re: Greenhouse - hydroponics vs soil

Off the Scale

Oldfart1939 wrote:

As Spacenut has indicated above, there are several mass limitations involved, rendering hydroponics as an interesting impracticality.

Mass limitation?  If you ship basalt to Mars, as SpaceNut suggested, then yes, mass becomes limiting.  Otherwise, no.

Oldfart1939 wrote:

Hydroponics could serve for crops such as Bush variety squashes (Zucchini, Yellow Crookneck), Tomatoes, Lettuce, Bush Beans, etc. but would be a real pain to use for grain crop production on a large scale.

The highest crop productivity in recorded history was a hydroponic grain (wheat, noted previously). 

Water, light, air, nutrients: which of these can't scale?

2e917f5260d9ead72f5ec7549fe6f01f.jpg

Last edited by Lake Matthew Team - Cole (2016-12-30 22:27:42)

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#137 2016-12-30 22:17:22

Lake Matthew Team - Cole
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Re: Greenhouse - hydroponics vs soil

GW Johnson wrote:

Most of the useful plants we have are more symbiotic with the organisms in the feces than most folks want to admit.  We are not yet capable of engineering plants that do not need such symbiosis long-term. 

By the way,  although I most definitely do not claim to be an agricultural expert,  I have personally seen this process in action.

The world's most productive crop plant doesn't need that symbiosis, obviously.  What crops did need that symbiosis, in your personal experience, and why?

To your knowledge, do any of these notional LMT greenhouse crops need it?

Last edited by Lake Matthew Team - Cole (2016-12-30 22:26:09)

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#138 2016-12-30 22:28:49

SpaceNut
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Re: Greenhouse - hydroponics vs soil

Here is a List of different types of growing media for hydroponics which are considered to be sterile, porous, non degradable.

http://www.homehydrosystems.com/mediums … wing_media

So the answer to not bringing Rockwool which is composed primarily of granite and/or limestone which is super heated and melted, then spun into a small threads like cotton candy would be to send machinery instead to make it.
The same is true of some of the others that are listed in the list from the link.

Equipment to make Rockwool on Mars, I think some of this could also be used on Basalt rock as well....
http://www.rockwool.in/why+rockwool-c7- … ol+is+made

http://www.olivotto.it/rock-wool/

This one is sort of OT but could be something for materials
http://www.rockwool.com/files/rockwool. … ochure.pdf
https://epd.georgia.gov/sites/epd.georg … /IC-10.pdf

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#139 2016-12-30 22:43:49

Lake Matthew Team - Cole
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Re: Greenhouse - hydroponics vs soil

SpaceNut wrote:

Here is a List of different types of growing media for hydroponics...

Sand is one of them.  Why ship a monstrous 1600 C stone wool furnace and factory to Mars, to make a product that simply isn't needed?

Last edited by Lake Matthew Team - Cole (2016-12-30 22:45:55)

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#140 2016-12-30 23:32:26

SpaceNut
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Re: Greenhouse - hydroponics vs soil

Yes sand is one but they require the nutrient fertilizers...

Plants require 16 elements for growth and these nutrients can be supplied from air, water, and fertilizers.

http://www.wikihow.com/Mix-Hydroponics-Nutrients

calcium nitrate, potassium sulphate, potassium nitrate, mono potassium phosphate, and magnesium sulphate, boron, chlorine, copper, iron, manganese, sodium, zinc, molybdenum, nickel, cobalt, and silicon

Preparing Your Own Hydroponic Nutrients : A Complete Guide for Beginners

Nutrient Solution Formulation for Hydroponic (Perlite, Rockwool, NFT) Tomatoes in Florida

Hydroponic vegetable production

These are concentrated minerals not parts per million which might be present so it would mean bringing them from Earth...initially

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#141 2016-12-31 00:11:58

Lake Matthew Team - Cole
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Re: Greenhouse - hydroponics vs soil

SpaceNut wrote:

Yes sand is one but they require the nutrient fertilizers...

Which doesn't answer my questions to you.  Why pack ITS cargo ships with stone wool, or else with a monstrous furnace and factory for making stone wool? 

The product isn't needed as hydroponic substrate because sand also serves as substrate, and the product isn't needed for fertilization because it's inert, without inherent nutrients.

So, why?

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#142 2016-12-31 00:34:48

Lake Matthew Team - Cole
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Re: Greenhouse - hydroponics vs soil

SpaceNut wrote:

Plants require 16 elements for growth and these nutrients can be supplied from air, water, and fertilizers...

These are concentrated minerals not parts per million which might be present so it would mean bringing them from Earth...initially

The micronutrients total less than 1% of plant mass, so naturally you'd ship them on a pallet.  There's no need for ISRU extraction, but some might be recovered as byproducts or impurities of macronutrient fertilizer production.

The macronutrients can be supplied efficiently via ISRU in fertilizer plants based on existing commercial / crewed mission tech.  You could use, for example, a small ZLD plant, a plasma nitrate plant, a Calera ABLE plant, stalk-and-greens composting and ECLSS urea recovery.  That should meet 90%+ of macronutrient need, at a scale that feeds all crewed missions, planet-wide, indefinitely.  There's no reason to ship massive ITS cargoes of macronutrients, ever.  Just ship efficient fertilizer plants and hook them up to their feeds.

Last edited by Lake Matthew Team - Cole (2016-12-31 08:52:05)

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#143 2016-12-31 01:12:20

Oldfart1939
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Re: Greenhouse - hydroponics vs soil

My REAL objection to hydroponics is very pragmatic; it's one thing to GROW the crops. but harvesting takes considerable effort. If one is talking about grains, it takes different pathways for them. Some, such as oats, are first mowed and cured in the sunlight before threshing. Wheat is simply cured on the stalk before threshing. Doing this over hydroponic beds is pretty impractical, regardless of the theoretical yields. Going the hydroponic highway violates my basic principle of KISS!

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#144 2016-12-31 08:41:43

Lake Matthew Team - Cole
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Re: Greenhouse - hydroponics vs soil

Oldfart1939 wrote:

My REAL objection to hydroponics is very pragmatic; it's one thing to GROW the crops. but harvesting takes considerable effort. If one is talking about grains, it takes different pathways for them. Some, such as oats, are first mowed and cured in the sunlight before threshing. Wheat is simply cured on the stalk before threshing. Doing this over hydroponic beds is pretty impractical, regardless of the theoretical yields. Going the hydroponic highway violates my basic principle of KISS!

When summer ends and LEDs go dark and sprinklers dry out and bees and drones nap, it's just a field of wheat.  Close-packed wheat on sandy ground.  The harvesting of this hydroponic wheat field introduces no "impractical" drama, as far as I can see.  Are you sure you're not introducing the impracticality yourself?

Last edited by Lake Matthew Team - Cole (2016-12-31 11:32:46)

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#145 2016-12-31 15:01:19

SpaceNut
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Re: Greenhouse - hydroponics vs soil

Lake Matthew Team - Cole wrote:
SpaceNut wrote:

Yes sand is one but they require the nutrient fertilizers...

Which doesn't answer my questions to you.  Why pack ITS cargo ships with stone wool, or else with a monstrous furnace and factory for making stone wool? 

The product isn't needed as hydroponic substrate because sand also serves as substrate, and the product isn't needed for fertilization because it's inert, without inherent nutrients.

So, why?

The furnace was for building materials which happen to be useful in the creation of the rockwool as well but which after a small amount of research into the product is found to be not necessary for the type of hydroponic sand growing medium which do require trays, a means to transport into the greenhouse, and ablility to stack trays vertically inside the greenhouse still plus the methods for despensing as I can see this would be laborous by hand to water the crops which the soil grown crops do require as well.

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#146 2016-12-31 16:17:45

Oldfart1939
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Re: Greenhouse - hydroponics vs soil

Lake Matthew Team-Cole

From your previous post, it strikes me that what you're describing if dry sand is where the final crops are located, you've created standard soli type agriculture? Kind of the "Long way around." I understand the wish to create an optimal new system, but the crop planners need some hands-on time before succumbing to theory.

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#147 2016-12-31 19:01:02

SpaceNut
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Re: Greenhouse - hydroponics vs soil

This post elsewhere may have been why I was not looking to use Sand....

Lake Matthew Team - Cole wrote:
RobertDyck wrote:

Mars doesn't have sand.

Does have sand.

Ed3Sck0.png?17529165592428414974

RobertDyck wrote:

Hydroponics has more "unknowns" than soil.

Martian soil and dust contain some known toxins: perchlorates, chromium, silicate dust and gypsum dust come to mind.  Other toxins may exist, but have yet to be isolated.  Now, you can eliminate those known and unknown toxins, and eliminate soil variability generally, by using rinsed, inert sand as the substrate.  That is, the hydroponic substrate. 

But to your mind, does that simplification introduce more soil variability, toxins, or unknowns?

Now keep in mind if its this or nothing then we go with some sort of sorting of the sand to reduce the contaminants that would be harmful...

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#148 2017-01-02 00:06:21

Lake Matthew Team - Cole
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Re: Greenhouse - hydroponics vs soil

Oldfart1939 wrote:

...what you're describing if dry sand is where the final crops are located, you've created standard soli type agriculture? Kind of the "Long way around." I understand the wish to create an optimal new system, but the crop planners need some hands-on time before succumbing to theory.

Visually this notional LMT hydroponics resembles "standard" soil agriculture, yes.  You wouldn't know it's hydroponic unless you scooped up the sand and observed the absence of organic matter and critters within.  Sterile and sterilizing hydroponic methods keep the greenhouse predictable and safe.  Standard agricultural methods are retained wherever possible, for familiarity and simplicity; as with, say, planting, harvest and composting.

I think most of us here are acclimated to the idea of a Mars greenhouse that's very cramped, using methods that scavenge every cubic meter of space:  i.e., dwarf crops, tightly stacked trays, even aeroponics that steal a little space by removing soil entirely.  Actually I can't recall, top of my head, a study that didn't pack everything tightly somehow.

Yet the Lake Matthew scheme enables construction of very large facilities, scaled to millions of cubic meters, and the LMT has had to re-acclimate to that space.  A Mars greenhouse with up to 17 acres of ground plots, and a multi-story "hanging garden" space for an additional 53+ acres - it's big.  And that difference compels us to think twice before stating some common notion of "cramped" Mars greenhouses.  In many cases the notion no longer applies.

If the Lake Matthew scheme is implemented, there will be time to perfect a greenhouse and other facilities beforehand.  It would make sense to deploy and debug the "optimal new systems" as a faithful production greenhouse copy, on Earth; testing it to the high standards typical of crewed mission tech.  Do that, and the first greenhouse on Mars is not an experiment, but a stand-up business that successfully feeds every crew on Mars, planet-wide; delivering perhaps even to crews in the asteroid belt.

Rocket_Pizza_Logo_Layton_Utah.png

Last edited by Lake Matthew Team - Cole (2017-01-02 09:52:02)

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#149 2017-01-02 12:19:26

SpaceNut
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Re: Greenhouse - hydroponics vs soil

Oldfart1939 wrote:

Lake Matthew Team-Cole- I have issues with the concept of using hydroponics. It's certainly possible for certain varieties of plants, but totally unfeasible for grain crops such as wheat, barley, oats, rye...etc. It's very difficult to harvest from hydroponic containers, at least in any quantity. I believe RobertDyck has already addressed the perchlorate issue, as perchlorates decompose upon addition of acids. We've mentioned a requirement for ammonium nitrate for Nitrogen, but a common additive to gardens in parts of the USA is Ammonium Hydrogen Sulfate. In particular, for growing Blueberries which require acidic soil. I've used the stuff as a surface dressing for my alkaline soil at my ranch. The Martian atmosphere is also a source of carbonic acid, simply by bubbling it through water and spreading on the soil. Gypsum dust is nothing other than dry Plaster of Paris, which is found at White Sands, New Mexico. Not really a toxin. Chromium in traces is an element required for proper function of the pancreas. As a rancher, I'd much rather deal with treating the regolith and conversion into a viable and fertile soil.

Lake Matthew Team - Cole wrote:
Oldfart1939 wrote:

I have issues with the concept of using hydroponics. It's certainly possible for certain varieties of plants, but totally unfeasible for grain crops such as wheat, barley, oats, rye...etc. It's very difficult to harvest from hydroponic containers, at least in any quantity.

"Containers"?  That's a misapprehension.  The LMT scheme grows half-acre plots.  No containers.  It's only hydroponic because it uses inert bedding substrate.  There's no obvious need for a complex soil.  Or is there?

Lake Matthew Team - Cole wrote:

Managing Greenhouse pH with Nitrogenous Fertilizers

Oldfart1939 wrote:

Another reason I mention the chickens is the benefit of chickensh*t, which is mostly composed of Uric Acid.

Urea is one of the first and easiest ECLSS extracts.  Membrane separate, sterilize, done. 

Both ECLSS urea and greenhouse plasma nitrate could be produced efficiently, using little electrical power.  The urea could complement the nitrate:  urea lowers soil pH, nitrate raises soil pH.  As envisioned in practice:  The IoT fertilizer software alters the urea/nitrate mixture for pH effect, and routes each mixture through the pump-grid "printer" to the plots, for easy pH balancing throughout the greenhouse.

They don't need the chicken uric acid.


With the soil / sand modified hydroponic plant food delivery system in a startup greenhouse for first mission. What we still need to nail down is the mass for the soil trays plus what depth sizes as that's crop dependant, support structure for trays not at ground level, quantity of hydroponic tubing for solution delivery plus other parts, Greenhouse mass plus shape to demensions, pressurization system, heating whether internal to greenhouse or in support of light externally reflected, air lock entrance ect....

The functioning greenhouse mass is still on the creep for what we would bring to mars but its got to be a minimal as possible initially and can be added onto with each mission in order to continue the build to larger crews that will eventually be permanent colonist.

Nailing done the first greenhouse size, shape and mass demensions, for what appears to be possible soil/ sand hybrid hyroponic plant food delivery seems to be the way we are talking about going but these are all based on what food crops we need to be growing of which we do not have a consolidated list as of this moment.

To do this still means this is a menu augmentation to what we bring rather than a sustainable farm which is what we want in the end run....but we need to start with something to create surplus food and this will do.

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#150 2017-01-02 22:19:31

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 19,158

Re: Greenhouse - hydroponics vs soil

Lake Matthew Team - Cole wrote:

Flow

Oldfart1939 wrote:

...a real "chemical engineering" type process flow sheet needs to be developed...

Would it make sense to start with a high-level ZLD water flow chart?  Many of the greenhouse's essential products, starting with water itself, could be made efficiently by a ZLD plant.  A water flow chart concisely relates the various ZLD solution inputs, outputs, devices and modes, with brief annotations and maybe color-coding.  Example:  Figure 3.  Water Flow Chart

Some of the ideas we've discussed at NMF have already been implemented commercially in ZLD plants.  For example, perchlorate removal - so important to Mars regolith/brine treatment - is actually a well-known commercial process:  insert an electrodialysis stack into the ZLD chain and the problem is solved.  Adding each vital component to the ZLD water flow chart, where appropriate, could pull NMF ideas together, and in a form that's easily communicated.

After, something similar might be done for the gas/cryogenic plant, and perhaps the ECLSS plant (which might be too complex for more than a partial chart of the most vital ECLSS flows).

The life support items with in the habitat would have this recycling system in place but using a simular system as put forth for processing the water extracted from soil, regolith ice brime concentration would be the way to utilize this in making water for the greenhouse....

Oldfart1939 wrote:

Lake Matthew Team-Cole;

You're thinking about technology far beyond what the FirstMars pioneers will be using. The processing equipment you have envisioned will all come from Earth, or by Mars manufacture after the basics are covered. Unfortunately I don't have an autoCAD  program available to me now. I'm trying to come up with a simple solution to a complex problem of running the supply streams and waste streams of the colony. I'm not wishing to get out my drafting stuff and do this all by hand, but if that's what it takes--so be it. I'm still in the conceptualization stage, but what you are thinking is years ahead of where the first few ships filled with long term residents need to be.

Lake Matthew Team - Cole wrote:
Oldfart1939 wrote:

You're thinking about technology far beyond what the FirstMars pioneers will be using. The processing equipment you have envisioned will all come from Earth, or by Mars manufacture after the basics are covered.

ZLD is just water treatment.  How would you expect the crews to treat raw freshwater or brine, anyway?  It's a core task requiring efficient, reliable tech.  ZLD seems appropriate.

And when you consider the fact that ZLD output gives a series of useful fertilizers, well, I don't know why you'd design a Mars greenhouse - even the first greenhouse - without it.

Oldfart1939 wrote:

Lake Matthew Team-Cole

I'm not saying that it's not a good system. Just the amount of mass required seems to be excessive for the early efforts at colonization. Your system would be 2nd Generation technology.

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