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#26 2016-01-16 20:59:51

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 18,212

Re: Greenhouses

Army helps to meet nutritional needs of Mars astronauts

Traveling to the second smallest planet in the solar system can give you a big appetite, not to mention special nutritional needs.
NASA contacted CFD researchers for their expertise and provided a grant for a vitamin stabilization project to help ensure the nutritional needs of astronauts are met during potential missions to Mars.

In a separate project, CFD is also working to improve and reduce the weight and volume of a breakfast meal replacement bar, originally developed by NASA, which would also be used during Mars missions and at a space station.
The mission to Mars provides many challenges in vitamin stabilization.

"You can make food that is stable, but vitamins are biological materials that degrade over time," Barrett said. "Especially if there is cosmic radiation; then they are even more susceptible to degradation. Cosmic radiation can damage vitamins and create more of a need for antioxidant vitamins for the astronauts. This could result in malnutrition."

The vitamins need to remain effective and intact during the astronauts' time on Mars, and they also need to remain stable during travel to and from Mars.

"NASA is also interested in stockpiling food there for subsequent missions, which is why they want a five-year shelf life," Barrett said.

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#27 2018-02-21 17:39:27

knightdepaix
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Registered: 2014-07-07
Posts: 230

Re: Greenhouses

Is photo upconversion helpful for greenhouses? Waste energy such as thermal in infrared is upconverted to artificial visible light or ultraviolet rays in greenhouses...

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#28 2018-02-21 19:01:21

RobertDyck
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From: Winnipeg, Canada
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Re: Greenhouses

knightdepaix wrote:

Is photo upconversion helpful for greenhouses? Waste energy such as thermal in infrared is upconverted to artificial visible light or ultraviolet rays in greenhouses...

How would you do that? A 40-watt fluorescent light tube used in commercial buildings has a drop of mercury, the tube is filled with an inert gas at low pressure, usually argon but could be mix of argon, krypton, and/or xenon. A coil at each end heats the gas, which evaporates the mercury. An AC electric current through the mercury vapour causes it to emit UV light, predominantly @ 253.7 and 185 nm. A fluorescent coating absorbs that UV light, and re-emits visible light. Fluorescent tubes are clear glass, the white coating inside the tubes is the fluorescent stuff. Notice it isn't transparent. How would you do this for a greenhouse window? Wouldn't a fluorescent coating block visible light? Sounds like you would need some complicated arrangement with mirrors. At some point a spectrally selective reflector would let visible light through, but reflect UV. The UV would be direct to a fluorescent coating. Sunlight has a broad spectrum, not just 2 frequencies; solar UV spans 100 nm to 400 nm, with most being 250 nm to 400 nm. A lot of solar energy is UV, but frankly most is visible light. Rather than some complicated mirror thing, I have argued for windows. Although my idea of long narrow greenhouses allow simple flat mirrors along the sides to concentrate light.

In the wavelength chart below, notice a sharp drop in irradience at the boundary between visible light and UV. That isn't a coincidence. Our eyes have evolved to make use of the brightest, most useful part of the spectrum. Actually, human retina (rods and blue cones) can see UV-A. However, natural human eye lenses have a coating that filters out UV. One guess why is so that our retina doesn't get sunburn.
800px-Solar_spectrum_en.svg.png

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#29 2018-02-22 10:20:08

elderflower
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Registered: 2016-06-19
Posts: 1,182

Re: Greenhouses

You can absorb light energy at a short wavelength and emit the energy at a longer wavelength. That's how fluorescence works. You can't emit it at a shorter wavelength as you would have to create energy due to the greater energy of shorter wavelength photons.

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#30 2018-02-22 10:36:57

knightdepaix
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Registered: 2014-07-07
Posts: 230

Re: Greenhouses

elderflower wrote:

You can absorb light energy at a short wavelength and emit the energy at a longer wavelength. That's how fluorescence works. You can't emit it at a shorter wavelength as you would have to create energy due to the greater energy of shorter wavelength photons.

Could more photons at the beginning of the upconversion gain energy from some of the photons? That meant number of photos decreases from the beginning to the end but the remaining photons gain energy. However the overall wave-mass content of the photons could remain constant albeit some loss leaving the upconversion process. Here I understand the energy of photons as the whole or part of the wave content within the wave-mass content of the photons

Last edited by knightdepaix (2018-02-22 10:55:11)

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#31 2018-02-23 04:43:28

elderflower
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Re: Greenhouses

That's how photosynthesis works. The chlorophyll system saves up the energy from, I think, 4 photons to carry out a water splitting reaction. The energy is then stored in a molecule called Adenosine Tri Phosphate. The energy from the phosphate ATP can then be released by the cell when and where it needs it. If the cell is equipped with the correct enzymes this can be emitted as light, as in fireflies and marine phosphorescence.

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#32 2018-03-02 18:29:05

knightdepaix
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Registered: 2014-07-07
Posts: 230

Re: Greenhouses

knightdepaix wrote:

Could more photons at the beginning of the upconversion gain energy from some of the photons? That meant number of photos decreases from the beginning to the end but the remaining photons gain energy. However the overall wave-mass content of the photons could remain constant albeit some loss leaving the upconversion process. Here I understand the energy of photons as the whole or part of the wave content within the wave-mass content of the photons

elderflower wrote:

That's how photosynthesis works. The chlorophyll system saves up the energy from, I think, 4 photons to carry out a water splitting reaction. The energy is then stored in a molecule called Adenosine Tri Phosphate. The energy from the phosphate ATP can then be released by the cell when and where it needs it. If the cell is equipped with the correct enzymes this can be emitted as light, as in fireflies and marine phosphorescence.

But is photo upconversion helpful for greenhouses? Waste energy such as thermal in infrared is upconverted to artificial visible light or ultraviolet rays in greenhouses... Infrared photons decrease in numbers but increase in energy in the form of emitting visible light and ultraviolet rays in greenhouses?

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#33 2018-03-18 21:29:29

SpaceNut
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Re: Greenhouses

underground greenhouse for year-round gardening

Growers in colder climates often utilize various approaches to extend the growing season or to give their crops a boost, whether it's coldframes, hoop houses or greenhouses.

Greenhouses are usually glazed structures, but are typically expensive to construct and heat throughout the winter. A much more affordable and effective alternative to glass greenhouses is the walipini (an Aymara Indian word for a "place of warmth"), also known as an underground or pit greenhouse.

walipini3.jpg

The Walipini, in simplest terms, is a rectangular hole in the ground 6 ‛ to 8’ deep covered by plastic sheeting. The longest area of the rectangle faces the winter sun -- to the north in the Southern Hemisphere and to the south in the Northern Hemisphere. A thick wall of rammed earth at the back of the building and a much lower wall at the front provide the needed angle for the plastic sheet roof

walipini.jpeg

This earth-sheltered greenhouse taps into the thermal mass of the earth, so that much less energy is needed to heat up the walipini's interior than an aboveground greenhouse. Of course, there are precautions to take in waterproofing, drainage and ventilating the walipini, while aligning it properly to the sun -- which the manual covers in detail.

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#34 2018-03-19 04:59:44

elderflower
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Registered: 2016-06-19
Posts: 1,182

Re: Greenhouses

I have seen a lot of similar structures in use in Northern China for the production of vegetables. They are assembled from dry bricks and sheeted with plastic on the South facing side. Use of dry bricks enables them to be dismantled, stored and resited as required.

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#35 2018-03-19 17:54:24

SpaceNut
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Re: Greenhouses

No worries if we are in a dome but since the first units will require sealing to the mars air since we will be in partial pressure for plants to live. Where the bricks will not give a seal to even a low pressure increase that would benifit the plants. Keeping the design simple means cutting a trench into the regolith and then covering with a weighted glass top just a double entry door system for coming and going. The chances of pulling up stakes are most likely not going be happening.

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#36 2018-03-26 12:45:57

Void
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Registered: 2011-12-29
Posts: 3,011

Re: Greenhouses

OK, a weird sort of "Greenhouse".  What else! smile

......

I seem to still be in pest mode, not in gone mode, not quite yet.
I have been pondering the high temperature solar cells discussed elsewhere, and it brought back a different type of notion of a greenhouse.
As you know, I have very little faith that a greenhouse of glass pressrized will not leak catastropically, eventually.
I would like to propose something else.  Not necessarily a one size fits all solution, but a potential option to consider, and not to club to death immediatly because it is relatively new!
https://phys.org/news/2016-08-high-temp … solar.html
......
Here is what I am after:  A device to work on the Martian surface, harvest electricity, and produce photosynthesis options in an enclosed chamber where the pathway of the energy is through non-transparent walls.  Using Black Body Radiation.
http://www.giangrandi.ch/optics/blackbo … body.shtml
1'000 K Red
1'500 K Reddish orange
2'000 K Yellowish orange
2'800 K Yellow
3'500 K Yellowish white
4'500 K Warm white
5'500 K White
......
800 DegC translates to 1073.15 K if I did the conversion right.
So of course I am thinking of a cone siting on the surface of Mars, pressurized, and with high temperature solar cells at or near it's apex.
The apex area will need to be of a materials that can endure being heated to 800 or more DegC daily.
So potentially Red light and near infrafed light passed through the metal and/or ceramic apex walls.
Heliostats with pneumantic motors most likely causing the concentrated light at the apex of the cone.
......
But I do not limit it to the temperature endurance of the solar cells.  The limitations will be of the tollerance of the metals and/or ceramics.  So, the solar cells can be eliminated from the absoulte apex of the cone, and moved down a bit.
In this way the Heliostats might heat the apex of the cone hotter than 1000 K, allowing shorter wavelengths in the visible light range to enter the inside of the cone.  Call it coneshine if you like.
But you can still have solar cells where it is cooler.
......
So why bother with this?
Well it  might be low maintenance and high productivity.
It is in range to use visible red light for photosynthesis, and also very likely to be able to even use near infrared for photosynthesis.
https://www.wired.com/2010/08/infrared-chlorophyl/
Quote:

A new kind of chlorophyll that catches sunlight from just beyond the red end of the visible light spectrum has been discovered. The new pigment extends the known range of light that is usable by most photosynthetic organisms. Harnessing this pigment’s power could lead to biofuel-generating algae that are super-efficient, using a greater spread of sunlight than thought possible.
http://bit.ly/2TwTeShttp://bit.ly/2TwTeS“This is a very important new development, and is the first new type of chlorophyll discovered in an oxygenic organism in 60 years,” says biological chemist Robert Blankenship of Washington University in St. Louis.
The newfound pigment, dubbed chlorophyll f, absorbs light most efficiently at a wavelength around 706 nanometers, just beyond the red end of the visible spectrum, researchers report online August 19 in Science. This unique absorbance appears to occur thanks to a chemical decoration known as a formyl group on the chlorophyll’s carbon number two. That chemical tweak probably allows the algaelike organism that makes chlorophyll f to conduct photosynthesis while living beneath other photosynthesizers that capture all the other usable light.
“In nature this very small modification of the pigment happens, and then the organism can use this unique light,” says molecular biologist Min Chen of the University of Sydney in Australia. Chen and her colleagues identified the new pigment in extracts from ground-up stromatolites, the knobby chunks of rock and algae that can form in shallow waters. The samples were collected in the Hamelin pool in western Australia’s Shark Bay, the world’s most diverse stromatolite trove.

So then one problem which might be apparent would be that some energy might tend to overheat the cone without providing for Oxadative Photosynthesis.
Well no problem I think, as you know I am always looking for heat on Mars.  In particular heat to melt ice, and as by that method to have heat to later shed into the Martian sky to generate electricity.  Particularly at night.
......
As my intentions for this device are to be productive, I reccomend a minimal internal air pressure, in fact phtotosynthesis being done by Cyanobacteria, and/or algae.  The production of chemecals such as fuels and Oxygen being the objective.
So during the day the critters do that chemestry, and a pool of water at the bottom of the cone protects them from overheating.  At night the pool of water protects them from freezing.
During the day you vent heat from the cone to a water reservoir.  During the night, the cone is a radiator.  You vent steam into it from the reservoir.  Generating electricty in the process.
Applause?  Ya sure you betcha sad  Raspberries indeed.  Invention frowned upon.

Last edited by Void (2018-03-26 12:48:37)


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#37 2018-03-26 15:27:59

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,898
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Re: Greenhouses

A friend suggested I build a Walipini at my house. But there are several problems. First, my back yard faces south, the garage blocks sunlight in the southwest corner, so the only place this could go is the gravel parking space beside the garage. Second is roof angle. Notice the image above in post #33. Sunlight is supposed to be perpendicular to the transparent roof at winter solstice. At the equator on spring or autumnal equinox, sunlight will be perpendicular to flat level ground, so the roof would be tilted 0° from horizontal. At northern latitudes, roof pitch will be equal to latitude. But that's at equinoxes. For sunlight to be perpendicular at winter solstice, roof pitch must be equal to latitude plus Earth's axial tilt. Earth has 23.4392811° tilt. The border between US and Canada is the 49th parallel, but my house is a little north of that. Specifically my house is 49.9110173° north latitude. So Walipini roof pitch should be 49.9110173 + 23.4392811 = 73.3502984°. You could round off to 73.35°, but that's a very steep roof! A Walipini just 11' wide and 16' long would fill the space available. At 16' long a roof pitch of 73.35°, roof height is Tan(73.35°)*16' = 53.5'. To ensure snow plowed from the back lane doesn't damage the roof in winter, there really has to be a short wall of 2' height, so the roof will be 53.5 + 2 = 55.5' high! My house has 9' ceilings for the ground floor, with 2x10 floor joists, subfloor and flooring, that means each floor is 10 high. That means this roof is the height of a 5 story building. My house and most houses on this block are 2 stories, that Walipini roof is rediculous!

Recalculating... If you make the roof perpendicular to sunlight at equinoxes, ignore axial tilt, then roof height is Tan(49.9110173°)*16' + 2' = 21.00802791', round off to 21'. That still means the Walipini is as tall as the eavestrough around my house. That's the Canadian term, the American term is "gutter". You could ignore sunlight angle, just make the roof 45° like my house. That would make it 16' + 2' = 18' high. If you do that, sunlight won't reach vegetables. The back wall of the Walipini would have to be covered in a mirror to reflect sunlight down into the dug-out, where plants grow. That means the mirror would have to be 11' wide by 16' high, to be level with the southern wall. You could use mirror tiles; if you use 1'x1' tiles, that will require 11x16 = 176 tiles. These are available from a construction supply store, current price is $16.49 + tax for a pack with 6 tiles. That will require 30 packs = $494.70 Canadian funds plus tax. Just for the mirror tiles!

My garage is 20 feet long. A Walipini 16 feet long leaves 4 feet behind for a shed or workshop. If the Walipini is the same length as my garage, then recalculate for 20' instead of 16'.

Then there's heat. A Walipini will extend growing season, but don't expect 12 months. Not here. When temperature is -31°C at night, real temperature not windchill, passive solar is not enough. It should extend growing season into mid November, and start in late March. That would be an 8 month growing season, which is better, but not 12.

Last edited by RobertDyck (2018-03-26 15:39:21)

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#38 2018-03-26 18:14:54

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 18,212

Re: Greenhouses

Just some more information to help drive up the temperature inside for all year round use. There are a variety of ways to implement the upgrades and a wide range of materials.

http://www.offthegridnews.com/survival- … ouse-warm/

https://www.mprnews.org/story/2014/02/0 … reen-house

https://en.wikipedia.org/wiki/Solar_thermal_collector

https://www.renewableenergyhub.co.uk/so … ctors.html

It also sounds like a PARABOLIC-TROUGHS COLLECTOR might work at the top of the greenhouse structure http://www.eolss.net/Sample-Chapters/C08/E6-106-05.pdf

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#39 2018-03-26 19:37:15

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,898
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Re: Greenhouses

If we're talking about Mars, what is the ground temperature? One engineer pointed out that Mars atmosphere is very thin, therefore won't transport much heat. Heat loss to Mars atmosphere will be slight. But Mars has cold ground, so most heat loss will be to the ground. A Walipini is based on the idea that Earth ground is warm in winter. Ground temperature a few feet below the surface has average temperature throughout the year; it doesn't get hot in summer, nor cold in winter. So digging down to that moderate, stable temperature means crops can grow year round. Or at least extend the growing season. But does that work on Mars?

This is temperature sensor data taken by Curiosity rover. It covers 1½ solar days (sols). Current Mars weather as I write this is reported for sol 2002, which is March 25, 2018. However, the graph presents temperature data for sol 10 and 11. Notice the mean is about -40°C, perhaps a little less. Peak temperatures are reported in °F; ground temperature varies from +37°F to -131.8°F, median is -47.4°F = -44.1°C. So burying a greenhouse will give you that temperature.
PIA16081_gomez3-br2.jpg

I suggest insulating the ground that the greenhouse sits on. An above ground greenhouse.

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#40 2018-03-26 19:56:05

SpaceNut
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From: New Hampshire
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Posts: 18,212

Re: Greenhouses

The floor of the greenhouse could be a raised floor such as to create an air gap to what we grow in a raised bed but ya an insulated floor would be important since mars appears to be ground cold....
Ground and Air temperatures

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#41 2018-03-26 21:25:11

Void
Member
Registered: 2011-12-29
Posts: 3,011

Re: Greenhouses

RobertDyck and SpaceNut.

That was very rude.

I don't care that much about the assessment of the attempt on invention that you circled around.  I am interested in looking inside of your heads.  What makes you behave like this.  I make a specific request for feedback and you rudely ignored me as if my thinking did not matter.  It is very insulting.

If you wish to insult then do it directly.

Now I have a demand.  Show me a greenhouse or a dome which has been pressurized at least to 1/3 bar above ambient Earth pressure and survived for a year.

Otherwise quite using such verbage as greenhouse or dome as if it is a proven technological solution.

Or just prove me right about what you are up to and do something else other than offering data on that.

If you can show it I will apologize.

Is this what you do SpaceNut when someone asks you for feedback.  Do you comprehend how filthy rude that is?

I'm done, and you sure need it.

Say you want me to leave and quit posting.  Doing what you do is filthy behavior.

Last edited by Void (2018-03-26 21:32:16)


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#42 2018-03-26 22:18:37

RobertDyck
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From: Winnipeg, Canada
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Re: Greenhouses

Void, I didn't respond because I didn't want to insult your idea. I have heard many people complain about radiation on Mars, claiming a greenhouse must be buried. I'm tired of that; if anyone is that scared of radiation, then they should stay home. Mars surface has half the radiation of ISS. And plants can endure much more radiation than people, so it's just not a concern. And I've posted many times about life support backup: an ambient light greenhouse is the only life support that works during complete power failure. It's efficient because you can use electric power for other things, but most importantly it provides oxygen and water during extended power loss. I'm constantly amazed at how many members of the Mars Society are that afraid of radiation. As Robert Zubrin said, it's like medieval maps with unexplored parts marked: "There be dragons here!"

There are ways to design a greenhouse with radiation shielding and still uses ambient light, but it's unnecessarily complicated. You can use a heliostat to track the Sun, reflect light into a light pipe. That pipe will direct sunlight through a small hole in the shielding, then a diffuser will spread that light out inside the greenhouse or habitat. Mars Homestead was designed to use that to illuminate the atrium. The atrium was intended to be a large open space for Mars settlers to relax, enjoy themselves. You could add potted plants, etc. But my assertion is that isn't necessary for a greenhouse. Or you could place a heavy shielding roof over the greenhouse, with overhang over the sides. Mirrors could reflect sunlight under the overhang, through side windows. Again, my assertion is this isn't necessary.

You want to use heat to produce light. Incandescent light bulbs use that principle. Electricity heats a tungsten wire in a sealed glass bulb filled with dry argon gas. The argon keeps oxygen out, ensuring the hot metal doesn't burn. The metal filament is heated so much that it glows. You can see the colour of light just by turning on any light fixture with an incandescent bulb. It works, but it wastes a lot of energy on heat. A 60 watt light bulb produces the same amount of light, measured in lumens, as as a 14 watt compact fluorescent lamp (CFL), or 9 watt LED bulb. And that's a sealed bulb; if the light emitting element is not sealed, it will release a lot of heat.

If you're trying to avoid photovoltaic cells for your sunlight collector, may I suggest a sterling engine? It has been proposed for space. It uses a parabolic mirror to focus light on a black collector. It heats one end of the engine, another end radiates heat away. The engine oscillates, moving a piston with magnets up and down through a coil of wire, producing AC electric current. You could then use the power to run LED light bulbs.

But the real point is I argue for a simple glass greenhouse. Glass will not leak. The only potential leak is the edges of the glass panes. That's where you use rubber gaskets. ISS has a multi-pane window called cupola. It uses a transparent material called Aluminum Oxynitride. For years I talked to everyone at NASA who would listen, trying to convince them to replace windows of Shuttle with this stuff. That would eliminate the need to hand grind the windshield after every mission. Everyone told me management doesn't want to reduce labour, that want to maximize expense because that means more profit. But the material I argued for is now on ISS! Yea! The point is it's just transparent material, sealed to the aluminum alloy frame with rubber gaskets. Very tightly sealed with bolts. Each window has multiple panes, each pane is separately sealed with rubber gaskets. It works, it's air tight.
716263main_iss028e048571_226.jpg
Tracy_Caldwell_Dyson_in_Cupola_ISS.jpg
2a8d2583-29e8-402b-b221-2d9a5f4997a4.jpg

And you can replace panes without decompression.
Z74.jpg

You keep threatening to leave. Don't leave. We don't have to agree about everything. Just because I don't agree with this one idea does not mean anyone here wants you to leave. At a NASA conference in Washington DC, I mentioned my chloroplast life support idea to one of the NASA hosts. She laughed in my face. I didn't laugh in your face.

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#43 2018-03-26 22:59:53

Void
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Registered: 2011-12-29
Posts: 3,011

Re: Greenhouses

Your appeal has reached me.

To be honest I was going to demand that you and SpaceNut show evidence that you could pressurize a greenhouse or a "Dome" to 333 mb above ambient or at least 70 mb above ambient.

I don't hate you guys, I just don't want Shetland poneys in  Antarctica.

I won't make that demand, but I want you to seriously think about it.  Where is such an event anywhere?

As for me leaving, it is a necessary rest for my spirit.

I think it is going to happen and needs to happen.

smile


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#44 2018-03-27 16:20:31

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 18,212

Re: Greenhouses

Void you really thought that there was no response when I gave information that when coupled with RobertDycks posts were nothing?
Well I am sorry so here is the thoughts:
High temperature solar cells most likely will be a smal quantity as these will be heavy with respect to the heatshink being built into the product. That said a few for a initial green house would be a poor use as these need lots of reflective panels as well to bring the potential heat and energy up to what they can produce. As a Helostat system thats a plus as a few gets you to a higher level of power and heat from them but even when no tower to use the principles still can be used. Think reflective dish with the panel at the focal point for maximum output but even that would not be a useable as the dish is heavy as well making that an insitu made item. So another low mass build is required if we are not able to make things with insitu yet.

If we were to use the high temperature solar panels as a roof the heatsink would have the channels fitted with a tube running the length just like a flat panel thermal heat collector is made. The working fluid could be any that we can make insitu or bring from earth to be stored in any tanks capable with support pumps. Use the stored heat as you will to warm the greenhouse or to make a warm shower.

Once you can maintain a space for a controlled environment any thing is possible within it. As for the pressure thats not a problem when the materials are naturally heavy up to the point in which the mass is over come by the float boyancy aspects of the pressure. A low pressure seal is possible and even if it leaks a bit we are want to have a supply of fresh co2 anyways, just monitor the rate and add when needed to keep the plants at a safe pressure for growing.

The plants that grow within this will give air that we can funnel off to a compressing pump to seperate out the oxygen as concentration rise with the greenhouse. The plant waste with the little critters can be made to create methane and even some heat from the composting process.

What I gave in links have content as it relates to the problems to which when you want a design with something you will run into concepts that do have issues and then you go about adapting the inital thoughts to make what you want work. The implemented design changes will take into account the inclination of location, materials use from insitu sources, equipment requirements and energy to make them run, and so much more as as initial thought comes to be.

We have variables on a timeline that are not yet there for any or what we would want...baby steps, crawl, walk, and run will happen in time but its controlled as we visit. It will not be all or nothing even with a BFR for use we still will be proceding on a slow path based on what we can do with what is sent. The trick is to use what is sent from the first and on each mission more than once if not in the form to which it is intend, then use it in another manner or melt it down....it all has a second use

Closing thought with a BFR cargo landing use that as the tower to mount the panels on once empty; just change what you have via modification into what you want.

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#45 2018-03-27 17:34:00

SpaceNut
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From: New Hampshire
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Posts: 18,212

Re: Greenhouses

For a reflective surface for RobertDyck you might get away with wood or plastic for a backing to glue on shiny Tin foil for the greenhouse or any other cheap materials( potaoe chip bags, mylar balloons) of which to help keep it from oxidizing spray on a clear coat paint. I would also line the walls inside to aid the reflecting as well to boost the light a bit. If you have a small wood stove or large can to burn a little wood or other stuff for supplemental heat, co2 or even a propane cook stove for when the temperatures take a dip at night.

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#46 2018-03-27 22:40:34

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 5,898
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Re: Greenhouses

Hmm. Yes. If only I had a job. Visions of tearing down my garage, building a brand new one. I could give details, but I found this at Amazon. Amazon Canada has free shipping within Canada. Reflective sticker, self-adhesive, 0.1cm thick (1mm), flexable. 50cm x 100cm, CDN$ 12.64 + tax. If the back wall is 18' high x 15' wide, that's 548.64 cm high x 457.2 cm wide, so make the reflective area 550cm x 450cm. That would require 5.5 x 9 rolls = 49.5 rolls. Purchased in whole rolls so 50 rolls. That's $632 + tax. A slightly larger area, but still expensive. And outside garage wall facing the Walipini could get more mirror covering. More money. hmm
51AzHGLBW8L.jpg
(Ps. I dug the URL of the image out of source code for their website. However, clicking on the image takes you to their store, to buy this item. They shouldn't be upset by free advertising.)

::Edit:: Hah! Even better. You suggested Mylar; I did a search and found this. One roll would do, CDN$ 49.99 + tax. Free shipping within Canada. Intended to reflect light for agriculture.
Growneer 4 x 100FT 2 Mil Horticulture Mylar Reflective Film Roll Highly Reflective Covering Sheets For Greenhouse Increasing Temperature Light
51+gzsvG8DL._AA160_.jpg

Last edited by RobertDyck (2018-03-27 23:26:27)

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#47 2018-03-28 18:20:01

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 18,212

Re: Greenhouses

I googled up "no water or clay sand bricks" and here is the links...

https://www.ehow.com/how_8097042_make-b … water.html

Make Your Own Bricks from Soil How to make bricks to build a home: including the five basics of blockmaking, soil composition, and mixing the bricks

5 Common Used Bricks Types: Classification and Uses

Conditions Needed For Brickmaking

Funny thing when you google you can find our discussions such as this one in Mars Colony Cement & Concrete

DIY Kinetic Sand: No Mess, Easy Clean Up, TONS of FUN!

What I was thinking of using is rtv and epoxy adhesives to bind and mold a wall of sand that is a sealed wall via the binding agents. If under experimentation we can not build a free standing wall then go for the trenched into hillside and just seal the walls and floor with this method.

This Engineer Is Building a DIY Mars Habitat In His Backyard: How Jeff Raymond is pioneering sustainable agriculture for Earth and Mars.

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#48 2018-03-29 09:52:35

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,620

Re: Greenhouses

Bricks made from Mars analogue soil:

https://www.popsci.com/mars-soil-bricks

I currently favour creating farm habs out of terraces on a Mars crater interior or hillside:  a lot less structure to build and a lot easier to construct.  Use areogel for internal insulation, particularly floors. Use reflective quadruple glazing for the windows. Have reflective roll material reflect light on to the windows from an opposite incline. Use thermogenic plants for additional heating at night. Use supplementary internal lighting and hot water pipe heating internally.

The reflective roll material referenced by Robert Dyck could be fixed to stone pillars constructed from Mars rocks and boulders found in the vicinity (they can be quite crude). With v. weak winds and no rain on Mars such supportive structures don't need to be too strong.

Last edited by louis (2018-03-29 09:53:31)


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#49 2018-03-29 10:35:16

elderflower
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Registered: 2016-06-19
Posts: 1,182

Re: Greenhouses

There should be plenty of Pozzolana (volcanic ash) in large deposits on Mars. Then you need burnt lime (or maybe burnt dolomite) and you can have Roman concrete.  The dome of the Pantheon is made of this.
There's some Roman masonry still standing not very far from here. It was constructed about 300 CE. It is pretty good stuff.

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#50 2018-03-30 16:08:01

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 18,212

Re: Greenhouses

The link for the mars soil is the rammed compressed brick that is a mix of minerals to make it hard but I am wondering about the stacking pressure that they can take and the obsorbsion rate of moist as to what will cause them to fall apart.

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