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Inspirational story. This family built a cob house under a glass dome in Northern Norway, well inside the arctic circle. They are able to grow tropical fruits and vegetables for much of the year. Of course, their dome is not a pressure dome and the Martian night is very much colder even at the equator. Even so, it is possible to imagine people on Mars living not too differently. The pressurised space within the Mars dome will be much more valuable. It would make sense to expand the structure to occupy as much of the dome as possible, so that no pressurised volume is wasted. Some form of cohousing would also save space by allowing different families to share the same facilities - kitchens, garden, shower facilities, etc. All exposed surfaces should ideally be covered in some sort of food producing plant. The dark surfaces absorb heat during the day and moderate the temperature drop at night.
http://inhabitat.com/how-one-family-thr … esic-dome/
Last edited by Antius (2017-01-02 15:11:49)
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Nice geodesic dome envelope construction combination....
Very nice
Construction materials could be laid flat in a cargo unit initially for a starter home greenhouse construction. Light mass plastics with aluminum framing could be used at lower internal pressures with additional shells being shipped on a regular scheduel. Once we can work inside we will be able to make use of more insitu resources and rely less on earth departing stuff....
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I hope you won't regard this as vandalism, just a morphing of the original idea.
Could you consider a canyon carved in sandstone, and a 1/2 reversed toroid glass arch in it to enclose a building? The buildings beams could then be anchored across the canyon walls, and of course into them. It would tend to be deficient in light, but I am hoping that a multiplex heliostat mirror system could then augment the amount of light in the enclosure. However, be aware that my experiments of shining a focused light through normal window glass lead to broken glass from thermal shock. This however could have been due to the high heat that was induced in the solar collecting box I used. The suddenness, and the intensity of the heat was too much. Maybe better glazing is also a hopeful solution.
But return to your own original model if this annoys you.
I am starting to ask seriously "Why do I do this?"
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There's no reason why the dome *has* to be at habitable pressures, or even be a dome at all. A low pressure (<100mb) greenhouse dome could contain within it a pressurised (>400mb) habitat, which would use the space in the dome for atmospheric buffering and life support. The greenhouse would provide oxygen, food, materials, clean water etc to the habitat in the centre, as well as keeping it warm(er). There would probably be a small garden as part of the habitat proper, perhaps as an atrium design, with apartments clustered around it.
Use what is abundant and build to last
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I am reminded in the greenhouse topics that mars is cold and that it will suck to heat out of things so we will want multiple domes, layers with hard vacumn and of different gasses to allow for the heat to stay in the dome that we live with in.
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Winter
I am reminded in the greenhouse topics that mars is cold and that it will suck to heat out of things so we will want multiple domes, layers with hard vacumn and of different gasses to allow for the heat to stay in the dome that we live with in.
A greenhouse designer provided heat loss calculations for various martian dome configurations (single-pane, double-pane, low-e IR filter).
Net net: His preferred 150 m dome, with double-panes and low-e coating, loses heat at a rate of ~800 kW in winter. Brr.
Last edited by Lake Matthew Team - Cole (2017-01-06 23:08:52)
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That suggests seasonality. At high latitudes, the lighting (Length of days) will likely be unfavorable to growing things in a greenhouse in the long Martian winter anyway. But refrigeration of food on Mars, will likely be easy, obviously.
Last edited by Void (2017-01-06 13:00:06)
I am starting to ask seriously "Why do I do this?"
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...refrigeration of food on Mars, will likely be easy, obviously.
Well, that's one easy thing there.
Greenhouse sterilization is pretty easy, too.
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Theres a nice big set of domes in Cornwall, UK. They are built in a former quarry and are known as "The Eden Project". Quite a visitor attraction. See loads of images by googling it.
Tom Harris "How the Eden Project Works" 3 May 2001.
HowStuffWorks.com. <http://science.howstuffworks.com/enviro … s/eden.htm> 6 January 2017
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800 Kw per hour? day? Isn't the case that because of the low pressure a habitat would lose heat more slowly?
SpaceNut wrote:I am reminded in the greenhouse topics that mars is cold and that it will suck to heat out of things so we will want multiple domes, layers with hard vacumn and of different gasses to allow for the heat to stay in the dome that we live with in.
A greenhouse designer provided heat loss calculations for various martian dome configurations (single-pane, double-pane, low-e IR filter).
Net net: His preferred 150 m dome, with double-panes and low-e coating, loses heat at a rate of ~800 kW in winter. Brr.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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800 Kw per hour? day?
Huh?
How thick would we need the insulation to be, to keep constant production in a greenhouse? How many layers of argon-filled bubblewrap are we talking about?
Use what is abundant and build to last
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Theres a nice big set of domes in Cornwall, UK. They are built in a former quarry and are known as "The Eden Project". Quite a visitor attraction. See loads of images by googling it.
Tom Harris "How the Eden Project Works" 3 May 2001.
HowStuffWorks.com. <http://science.howstuffworks.com/enviro … s/eden.htm> 6 January 2017
Yes, a great attraction, and a very successful design. More architectural details in Structural Design of Flexible ETFE Atrium Enclosures Using a Cable-Spring Support System.
The active monitoring system is interesting. It monitors and adjusts pressure in the ETFE cushions.
MATT subaqueous domes notionally apply that system to each hexagon's four stacked cushions, independently, to hold each cushion at a manageable max pressure delta of 11 kPa.
Last edited by Lake Matthew Team - Cole (2017-01-07 11:19:52)
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Radiative Heat Loss
800 Kw per hour? day? Isn't the case that because of the low pressure a habitat would lose heat more slowly?
Lake Matthew Team - Cole wrote:SpaceNut wrote:I am reminded in the greenhouse topics that mars is cold and that it will suck to heat out of things so we will want multiple domes, layers with hard vacumn and of different gasses to allow for the heat to stay in the dome that we live with in.
A greenhouse designer provided heat loss calculations for various martian dome configurations (single-pane, double-pane, low-e IR filter).
Net net: His preferred 150 m dome, with double-panes and low-e coating, loses heat at a rate of ~800 kW in winter. Brr.
800 kW continuous (roughly). True, at low pressure convective loss rate decreases. However radiative loss rate increases, dramatically, with the difference of the 4th powers of hot and cold surface temperatures. With a winter delta approaching 150 C, you can see how radiative heat loss becomes unmanageable.
Last edited by Lake Matthew Team - Cole (2017-01-06 23:08:14)
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How thick would we need the insulation to be, to keep constant production in a greenhouse? How many layers of argon-filled bubblewrap are we talking about?
You might try adding some bubblewrap insulation specs and layers with the spreadsheet author.
Opacity increases with each bubble film layer though. Experiment: How many layers are needed to block light? Divide by that number for transmission loss per layer. I'd guess a net transmission below 30% is not useful for growth, even in summer.
Last edited by Lake Matthew Team - Cole (2017-01-06 21:34:23)
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https://en.wikipedia.org/wiki/Extraterr … _from_Mars
The Sun as seen from Mars appears to be 5⁄8 the size as seen from Earth (0.35°), and sends 40% of the light, approximately the brightness of a slightly cloudy afternoon on Earth.
That seems lower than I thought. However on Earth plants typically need 10% of Earth sunlight to grow reasonably normal. (That is what I recall).
So, on Mars maybe you need 25% of Mars sunlight? (Minus the U.V.)
And that's one reason I like mirror heliostats.
Once you have a transparency, if it does not damage the window, why would you not direct just as many photons through it as you can. If it is too bright for the plants then you can shade them, and collect the heat.
But that brings another issue to mind. I recall hearing that greenhouses on Mars will overheat, which is a contradiction to what we have said so far. It is a thermally challenging environment either way.
Last edited by Void (2017-01-06 21:50:02)
I am starting to ask seriously "Why do I do this?"
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The Sun as seen from Mars appears to be 5⁄8 the size as seen from Earth (0.35°), and sends 40% of the light, approximately the brightness of a slightly cloudy afternoon on Earth.
Reasoning:
We got ~60% transmission of Mars light through MATT domes, for PPF > 13 during 9 months of the Mars year. It's enough for 3 consecutive natural-light harvests. (PPF 13 is the approximate requirement for strawberry growth. We used strawberries as proxy for all shade crops.)
A 30% transmission would have dropped PPF below 13, likely causing crop failure in absence of LED substitute.
Last edited by Lake Matthew Team - Cole (2017-01-06 22:18:48)
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Keep in mind that in part I am trying to catch up. You could easily catch me stupid in all this.
But maybe a solution will come.
I will step back until I understand more of what you present.
Last edited by Void (2017-01-06 21:54:52)
I am starting to ask seriously "Why do I do this?"
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Underground chamber with lightpipe to funnel the light which can be concentrated before directing it into the lightpipe. This will work to isolate the plants from the heat lose and give them the light level that they need. So natural cave or some other low tech method which can be used to create with low amounts of energy or work to create would be perferable.
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Light Tubes
Underground chamber with lightpipe to funnel the light which can be concentrated before directing it into the lightpipe.
Unfortunately light tubes dim very quickly. Light tube modeling in Optik 124 (2013) 3165–3169 gives < 25% transmission using a short, effectively truncated, 4 m length of tube within a plausible dome geometry.
Last edited by Lake Matthew Team - Cole (2017-01-07 23:06:57)
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I was think of a multiple strand fiber optic glass molded with lensing on each end to all for the focused concentration and for spreading it back out once we reach the end. Not in the no of the Optik product... but in either case lighting from natural source will be an issue if we can not get the energy we require to keep the plants warm or for lighting for there growth.
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I was think of a multiple strand fiber optic glass molded with lensing on each end...
The light tube or guide in the Optik paper is a hollow reflector, so it should have higher transmission than a scheme that reflects through solid internal medium, even glass. Else they would have added a medium to improve it. Internal reflections just kill transmission through light tubes. It's a longstanding problem, apparently.
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You are talking about a SunTunnel which due to low angle of incident does cause reflection loss in the length of the tube which couples the lense at the surface to the diffuser lense at its bottom.
http://diy.stackexchange.com/questions/ … olar-tubes
Solatube Daylighting Systems come in 2 sizes, the 160 DS (10" in diameter) and the 290 DS (14"). The 160 DS produces up to 4600 lumens, while the 290 DS produces up to 9100 lumens. I have no idea what any other brand's lumen output is however, you will most always get more light with a Solatube brand due the fact that their tubing is made with Spectralight tubing (its patented) with 99.7% reflectivity. This means each time the light "bounces" down the tube, Solatube loses .3% of the light. With 5 "bounces" Solatube only loses 1.5%. If the tubing is less reflective - even by a couple of % points you potentially lose far more light. Reflectivity as given in percentage form is probably not a useful comparison, to be honest (and is this the CIE reflectivity or reflectance?). The shape of the tube, length of the tube, and configuration of the optics are all going to play a role in the perceived brightness. Additionally, it is not an additive loss in flux but rather a geometric loss with each reflection of an incident ray. The luminous flux (lumens), a measure of light perceived from all directions, is a far more useful measure. Without this value to compare it is hard to tell the difference
Most people are more concerned with heat loss through the Sun Tunnels which are simular to a double pane glass window. A U-Factor rating determines the amount of heat that is lost through an object. The lower the number, the better the insulation value. As a basis for comparison, a double-pane window typically receives a 0.4 U.S./I-P.
The Chroma Skylight Tube 2014ST is given a U-Factor of 0.3 U.S./I-P by the National Fenestration Rating Council (NFRC), better than a typical double-pane window.
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Laser Communication in Space, a Solution for Fast and Secure Communication
http://www.parabolicarc.com/2022/08/02/ … unication/
Antarctic Agriculture Helps Grow Food in Space
https://www.foodmanufacturing.com/ingre … d-in-space
Growing plants in space
As people began spending longer times in space toward the end of the 20th century, astronauts began putting to use the lessons from a century of growing plants in Antarctica.
In 2014, NASA astronauts installed the Vegetable Production System aboard the International Space Station to study plant growth in microgravity. The next year, they harvested a small crop of lettuce, some of which they then ate with balsamic vinegar. Just as Antarctic scientists had argued for many years, NASA asserted that the nutritional and psychological value of fresh produce is “a solution to the challenge of long-duration missions into deep space.”
Antarctic research plays an important role for space to this day. In 2018, Germany launched a project in Antarctica called EDEN ISS that focused on plant cultivation technologies and their applications in space in a semi-closed system. The plants grow in air, as misters spray chemically enhanced water on their roots. In the first year, EDEN ISS was able to produce enough fresh vegetables to comprise one-third of the diet for a six-person crew.
Just as in Antarctic history, the question of how to grow plants is central to any discussion of possible human settlements on the Moon or Mars. People eventually abandoned efforts to cultivate the harsh Antarctic landscape for food production and turned to artificial technologies and environments to do so. But after over a century of practice and using the most modern techniques, the food grown in Antarctica has never been able to support many people for very long. Before sending people to the Moon or Mars, it might be wise to first prove that a settlement can survive on its own amid the frozen southern plains of Earth.
The Arctic Dome of Glød Explorer is situated deep in the forests of beautiful Alta in Northern Norway. Through the glass windows, you can enjoy nature and northern lights.
https://nordnorge.com/en/aktivitet/arct … ta-norway/
With a worldwide reputation, and recognised by the British Travel Awards as the Best UK Leisure Attraction five years running, Eden barely needs an introduction, but this epic destination definitely deserves a day of your undivided attention. More than just a huge, tropical garden, Eden is a gateway into the relationships between plants and people, and a fascinating insight into the story of mankind's dependence on plant life. Not only a mind-blowing visitor attraction, Eden is also fast-becoming a unique resource for education and knowledge towards a sustainable future.
https://www.visitcornwall.com/things-to … en-project
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