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#1 2007-11-12 15:46:57

JoshNH4H
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From: Pullman, WA
Registered: 2007-07-15
Posts: 2,526
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Re: Greenhouses

as part of the tenet of ISRU, as well as logistics, it would be better if food (most or all) could be grown on mars.  What are some plans to do so for, say, a 4 person crew?  Obviously, there should be at least some exposure to the sun, as growing lights are costly in energy and mass terms.  Should they be aboveground, or a small shaft with a clear roof?

this is a good paper about food on mars, but how can we do these things?
www.lpi.usra.edu/publications/reports/C … dMars2.pdf


-Josh

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#2 2007-11-12 17:04:36

Grypd
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From: Scotland, Europe
Registered: 2004-06-07
Posts: 1,860

Re: Greenhouses

The problem with growing plants on Mars is that it has as much light hitting it at Noon as we have in dusk at winter. Plants will need a lot more light and this may need mirrors to focus more to where it is needed or plants that are less light needing


Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#3 2007-11-13 07:09:37

maxie
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From: Europe
Registered: 2005-02-15
Posts: 84

Re: Greenhouses

Most plants will do just well even at lower light levels. Why ?

First, because a lot of edible plants do not grow normally at Earth's equator, thus they are already adapted to lower light levels.

Also, on Earth we have clouds, thicker atmosphere (which is never 100.00% transparent), and more important: most edible plants on Earth are used to growing in the shadow of bigger plants. Grains for example are a notable exception to this.

And the most important thing to remember: to most plants, if not all, photosynthesis starts at very low light levels. I said some time ago that I have an aquarium with light levels a lot smaller than the natural light, and for most plants I observed only one thing: they grow fine, but just a little slower.

There is an article on the NewMars wiki about greenhouses, written by C.M. Edwards (probably one of the best articles we have), read that too:

http://www.newmars.com/wiki/index.php/Greenhouse

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#4 2007-11-14 07:06:13

Antius
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From: Cumbria, UK
Registered: 2007-05-22
Posts: 1,003

Re: Greenhouses

The problem with growing plants on Mars is that it has as much light hitting it at Noon as we have in dusk at winter. Plants will need a lot more light and this may need mirrors to focus more to where it is needed or plants that are less light needing

Not quite.  Martian average sunlight levels are 43% of Earth's.  Earth's sunniest regions are its equatrial deserts, which average about 2500KWh/m2/yr.  Applying the 43% factor gives Martian equatorial sunlight levels of about 1000kWh/yr.  This is about the same level of sunlight as in Southern England - one of the most productive wheat growing areas in the world.  Generally agriculture should do well at equatorial Martian light levels.  As you head away from the equator, yields may start to suffer and cerial crops will generally take longer to mature.  This will be an economic rather than practical problem, given the cost of greenhouses. 

Given the cost of power for early mars settlements, artificial lighting of crops would appear unlikely.  The situation may change with the development of fully fledged Martian industries, capable of manufacturing large nuclear reactors from entirely native resources.

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#5 2007-11-21 18:35:23

Grypd
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From: Scotland, Europe
Registered: 2004-06-07
Posts: 1,860

Re: Greenhouses

You must remember that the light on Mars is pure unfiltered sunlight and as such is effectively very heavy in the Ultra-voilet range. Though we do have plants with some resistance to this we will have no choice but to filter this light and that will drastically reduce light that could get into a greenhouse. Now add the need to keep air in and of course heat and you have a lot of filtering. Our plants that we consider staple diet will struggle to even sprout never mind thrive. We can create greenhouses where we redirect the light but not the ultravoilet but these will not make for a good design to feed large colonies.

You will effectively be growing plants at the equivalent of the artic circle.

Still thats the cards we have and so we have to cheat. Plants can be modified GM crops and so they can be made tougher in both resistance to cold as well as to the sterilising ultra voilet radiation. In that case maybe they can also be made to live better in the Martian nutrient poor regolith.

Still we will be unlikely to be able to eat them but that is not the point as when they die and go through the life process a while we will begin to get soil which is not so nutrient poor and with plants not so unedible though weaker we can then have something we can grow large crop yields from without constant supervision in not so complicated greenhouses.


Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#6 2007-12-01 22:52:46

Commodore
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From: Upstate NY, USA
Registered: 2004-07-25
Posts: 1,021

Re: Greenhouses

I don't see an issue with power shortages, but grow lights do burn out and are fragile. Your going to have to use as much available light as possible.

A Hydroponic greenhouse of the Earth salad bar staples and cereals for man and beast is vital to all our efforts. Nuclear surface, and even transit power is almost a necessity, if not a given already, so our heating and lighting supplements are covered. The biggest remaining issues are bulk scale nutrient creation, and ensuring a clean primary light source.


"Yes, I was going to give this astronaut selection my best shot, I was determined when the NASA proctologist looked up my ass, he would see pipes so dazzling he would ask the nurse to get his sunglasses."
---Shuttle Astronaut Mike Mullane

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#7 2007-12-03 18:29:11

MarsRefresh
Member
From: Spokane, WA, USA
Registered: 2007-11-19
Posts: 48

Re: Greenhouses

Grypd wrote:

You must remember that the light on Mars is pure unfiltered sunlight and as such is effectively very heavy in the Ultra-voilet range. Though we do have plants with some resistance to this we will have no choice but to filter this light and that will drastically reduce light that could get into a greenhouse.

In Zubrin's The Case For Mars, he suggests using an unpressurized Plexiglas dome on top of a pressurized Kevlar dome (page 177). For a 50 m diameter sphere the Kevlar would weigh 8 tonnes and be only 1 mm thick. The Plexiglas "sheild" would weigh only 4 tonnes, presumably because it would only be a half-sphere in this example. However, when I checked into Plexiglas - http://www.plexiglas.com/acrylicsheet/a … etfamily#9 - it seems that it requires a coating or treatment to reduce the ultraviolet spectra. I have not found out what this treatment is or how it's applied, but the site says that (presumably at terrestrial levels) UV are reduced by 99%. In a Martian setting this coating would be on the inside surface and the untreated surface would face outward, towards the environment. If it remained 99% effective, I don't think we need worry about the plants (or people).

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#8 2007-12-03 18:43:27

MarsRefresh
Member
From: Spokane, WA, USA
Registered: 2007-11-19
Posts: 48

Re: Greenhouses

I don't see an issue with power shortages, but grow lights do burn out and are fragile. Your going to have to use as much available light as possible.

A Hydroponic greenhouse of the Earth salad bar staples and cereals for man and beast is vital to all our efforts. Nuclear surface, and even transit power is almost a necessity, if not a given already, so our heating and lighting supplements are covered. The biggest remaining issues are bulk scale nutrient creation, and ensuring a clean primary light source.

I quite agree that we go nuclear or we don't go at all. But I think we need to stick with sunlight for crop growth given the power needed. Nuclear power is great, but it has limits. I cannot imagine a successful base without in situ production/capture of gases, water, fuel, plastics, and iron/steel as well as excavation. All of these are power hogs and spending little energy on food production would really help. What do you think?

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#9 2007-12-04 06:57:57

JoshNH4H
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From: Pullman, WA
Registered: 2007-07-15
Posts: 2,526
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Re: Greenhouses

I agree.  The sp-100, which seems the most likely choice, only generates 100  kwe of energy. (is that a lot?  The goal for it was 300 kwe.  I've heard that the first expeditions will need 1-200 kwe.)


-Josh

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#10 2007-12-05 22:34:05

Commodore
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From: Upstate NY, USA
Registered: 2004-07-25
Posts: 1,021

Re: Greenhouses

I don't see an issue with power shortages, but grow lights do burn out and are fragile. Your going to have to use as much available light as possible.

A Hydroponic greenhouse of the Earth salad bar staples and cereals for man and beast is vital to all our efforts. Nuclear surface, and even transit power is almost a necessity, if not a given already, so our heating and lighting supplements are covered. The biggest remaining issues are bulk scale nutrient creation, and ensuring a clean primary light source.

I quite agree that we go nuclear or we don't go at all. But I think we need to stick with sunlight for crop growth given the power needed. Nuclear power is great, but it has limits. I cannot imagine a successful base without in situ production/capture of gases, water, fuel, plastics, and iron/steel as well as excavation. All of these are power hogs and spending little energy on food production would really help. What do you think?

Of course you have to take full advantage of everything that is free. But we can't depend on it either. Remember on the moon we have two weeks with/without the sun, and Mars has dust storms. We have to plan to produce a baseline level of light regardless.


"Yes, I was going to give this astronaut selection my best shot, I was determined when the NASA proctologist looked up my ass, he would see pipes so dazzling he would ask the nurse to get his sunglasses."
---Shuttle Astronaut Mike Mullane

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#11 2007-12-08 00:18:19

MarsRefresh
Member
From: Spokane, WA, USA
Registered: 2007-11-19
Posts: 48

Re: Greenhouses

Commodore wrote:

Of course you have to take full advantage of everything that is free. But we can't depend on it either. Remember on the moon we have two weeks with/without the sun, and Mars has dust storms. We have to plan to produce a baseline level of light regardless.

Great point. I have not considered the effect of dust storms on agriculture. I've been doing some research and there seems to be two options. As you suggest, make sure that there is enough electrically produced light to keep plants alive even in the teeth of a dust storm. I have not found a study that clearly analyzes the amount of dust storms or the amount of sunlight that fails to reach the surface. But the depths of the storm that nearly killed off the MERs Spirit and Oppoirtunity seem to have created very dark conditions on the surface:
www.sciencedaily.com/releases/2007/07/070727174944.htm
But I've found that the dust storms arrive after perihelion and the biggest ones that block a lot of light come about 1 or 2 months after.
So the second option would be to farm around these storms. For an equitorial base, the normal amount of illumination should not vary too dramatically from perihelion to aphelion. Knowing that the worst, potentially crop-killing storms come one month after perihelion and that this season lasts around four months total, then an equitorial base would still have 20 of approximately 24 months in the martian year to farm with available sunlight.
So the trade off seems to be, do we install the infrastructure to allow for year-round farming - a definate plus - or do we farm when we can with available sunlight? Assuming nuclear power, then the crops would be planted and grow by diverting power from other base activities. However - and I think this is the best feature of a lighting system - if a dust storms does not come dancing by you get your crops and your power for that four month period.

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#12 2007-12-13 23:44:54

MarsRefresh
Member
From: Spokane, WA, USA
Registered: 2007-11-19
Posts: 48

Re: Greenhouses

Here is an exciting find by the Spirit Rover:

http://www.universetoday.com/2007/12/13 … more-12214

Zubrin in The Case for Mars noted that although the soil seems to hold a lot of silicon in was mixed with lots of iron that would make it hard to get optical level glass or the ultrapure silicon for solar panels. Then Spirit spins a wheel and discovers a whitish layer of 90% S and this is laced with titanium. Zubrin suggests blasting the silicon with Hydrogen to produce silane and then pumping it away from your impurities (in this case titanium). Then keep the silane (SiH4) as a fuel that burns in CO2 or seperate it with heat and keep the silicon or glass or solar panels or semiconductors. And what would that titanium be used for...

If large quantities are available and glass greenhouses can be constructed on any scale then the thermal weakness of polyethylene could potentially be bypassed.


Edit: I found an intersting thread that addresses many of these issues:
http://www.newmars.com/forums/viewtopic … 13&start=0

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#13 2008-01-03 13:26:22

Dragoneye
Member
From: Romeoville, IL
Registered: 2005-08-17
Posts: 100

Re: Greenhouses

If power isn't an issue then i'd suggest a nice sized hydroponics system in place would be a HUGE bennifit to the mars team. they can get water from the ice on the planet for water systems (cut out huge chunks and purify them as they melt) and then keep it under close eye... once you have plants setup to grow there then you'll have a STRONG food base. and anything that goes bad put it in a tank for a "compost pile" and collect the gasses to produce methane and the soil for later planting other forms of vegitation.

it wouldn't be teribly hard to be able to set up a bit station with make shift panels made there on the surface its self. so everything should be taken care of decently easily.

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#14 2008-01-12 12:18:41

MarsRefresh
Member
From: Spokane, WA, USA
Registered: 2007-11-19
Posts: 48

Re: Greenhouses

After pouring back through the old posts, it seems that Robert Dyck's proposal of PCTFE for greenhouse material is the best bet. But it still seems than a PCTFE greenhouse would get cooked by UV radiation. The UV coatings are metals and eliminate the transparency for visible light as well. Am I correct in this? Are there any plastics which block UV, while allowing visible and infrared? It sounds like Kevlar does, but in so doing it breaks down rapidly.

If not, does anyone have information on the UV resistance of glass?

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#15 2008-01-13 09:56:59

Dragoneye
Member
From: Romeoville, IL
Registered: 2005-08-17
Posts: 100

Re: Greenhouses

After pouring back through the old posts, it seems that Robert Dyck's proposal of PCTFE for greenhouse material is the best bet. But it still seems than a PCTFE greenhouse would get cooked by UV radiation. The UV coatings are metals and eliminate the transparency for visible light as well. Am I correct in this? Are there any plastics which block UV, while allowing visible and infrared? It sounds like Kevlar does, but in so doing it breaks down rapidly.

If not, does anyone have information on the UV resistance of glass?

why worry about that? why not just ship over bulbs for planting... its prooven to work, so why not use it? besides you can keep the plants on any kind of schedule you want then instead of a specific one. mars based. and as for the exterior paneling you can use what ever you want instead of a transparent one.

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#16 2008-01-13 10:02:56

Terraformer
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From: Lancashire
Registered: 2007-08-27
Posts: 3,270
Website

Re: Greenhouses

Remember on the moon we have two weeks with/without the sun,

Have you heard of 'Peaks of Eternal light'? They're areas on the moon where its rotation and tilt means sunlight is always hitting them. They're found at the North/South poles, which also have water ice? and other such stuff.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#17 2008-01-13 17:01:51

MarsRefresh
Member
From: Spokane, WA, USA
Registered: 2007-11-19
Posts: 48

Re: Greenhouses

After pouring back through the old posts, it seems that Robert Dyck's proposal of PCTFE for greenhouse material is the best bet. But it still seems than a PCTFE greenhouse would get cooked by UV radiation. The UV coatings are metals and eliminate the transparency for visible light as well. Am I correct in this? Are there any plastics which block UV, while allowing visible and infrared? It sounds like Kevlar does, but in so doing it breaks down rapidly.

If not, does anyone have information on the UV resistance of glass?

why worry about that? why not just ship over bulbs for planting... its prooven to work, so why not use it? besides you can keep the plants on any kind of schedule you want then instead of a specific one. mars based. and as for the exterior paneling you can use what ever you want instead of a transparent one.


Whether you use it for agriculture or architecture, a transparent structure is aesthetically far superior to subterranean dwellings. I cannot imagine many people moving to Mars if they cannot see the real sky above them. I also continue to worry about power generation, at least until your system is proven, let's say. Even fusion will have limits. I don't see the point in living underground on Mars when we could more easily live underground in Tibet or the Atacama desert. (And I do not worry about the "survival of our species" in the physical sense like many other Mars settlement advocates do.)

I should note that the

Spectrally Selective low-e glazing can the most dramatic protection for UV and IR. By trapping InfraRed light in, radiative heat is kept in. IR is radiant heat. According to the graph to the right, spectrally selective transmits 82% of violet light, 85% of blue and green, but 45% of orange and 30% of red.

from the Greenhouse link still reduces visible light quite a bit.

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#18 2008-03-28 19:30:48

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,780

Re: Greenhouses

My sense is it is just a lot quicker and efficient to go for full artificial lighting. Given the existence of dust storms on Mars, any greenhouse system dependent on natural light could result in crop failure. If you are going to make it non-dependent on natural light (so crops can survive prolonged dust storms) then you will have to provide a full artificial light system and that in itself will block out natural light - so, not a good solution.

Also put the farms underground for radiation protection.

My guess is that something like 100 square metres (2 metre high) would provide enough food for 4 people with a hydroponic system growing crops on two levels and with crop choices being directed to those with short growing seasons (anything from five days to 60 days). It would be highly intensive agriculture but with perfect growing conditions, provided by the artificial light, controlled heat and humidity, water supply and nutrient solution,  there is no reason why it shouldn't work.


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

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#19 2015-11-26 10:34:33

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 18,536

Re: Greenhouses

We seem to be rehashing the same topics of old all over again rather than connecting them together.....

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#20 2016-01-02 21:29:06

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 18,536

Re: Greenhouses

Here is a neat web site that contains some for information for greenhouses....

http://geodesic-greenhouse-kits.com/hom … se_design/

At bottom of page there are more links to these topics:

Winter Gardening in a Growing Dome: No Heat Required

Aquaponics Greenhouse System: Part 3

Cycling your Greenhouse Aquaponic System

Aquaponics Greenhouse System: Part 2

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#21 2016-01-03 20:26:14

louis
Member
From: UK
Registered: 2008-03-24
Posts: 5,780

Re: Greenhouses

Somebody - maybe me! - needs to do a Mind Map to show how these issues all link in with each other.  OK I will put that on my to-do list!
smile

That said - what needs to be linked in? -

Rocket launches from Earth...

Transit...

Landings...

Robot missions/precursors...

Surface habs

Farm habs

ISRU - steel, basalt, crops, plastics etc

Life support - water, air, food

Gravity/health issues

Terraformation.


Could be fun...not sure I've seen anyone do a Mind Map for Mars colonisation before.




SpaceNut wrote:

We seem to be rehashing the same topics of old all over again rather than connecting them together.....


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

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#22 2016-01-03 21:23:14

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 18,536

Re: Greenhouses

With all the topics that we have discussed here and applying them to the criterior of the links above we have a pretty well designed mission plan....

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#23 2016-01-16 11:04:04

Tom Kalbfus
Banned
Registered: 2006-08-16
Posts: 4,401

Re: Greenhouses

greenhouse_hab_by_tomkalbfus-d9o5eny.png
How is this for greenhouse hab?, the upper floor is where we grow things, the lower deck is an equipment shed, and where we store produce, turns out on Mars, refrigeration is easy to come by.
Robot_en_marte.jpg
Suppose we had robots like this inside the greenhouse, the greenhouse has all the things we need to grow produce. I'll bet you the requirements for sending plants to Mars are a lot less than for sending people. For one thing we don't have to return the plants to Earth. The robot farmers can be controlled from Earth just the way this Mars probe has been, things like seeds don't move very fast. I can imagine a robot like this with the right farming implements planting seeds and harvesting crops, then we need to freeze them. Perhaps freezers that exchange heat with the ground could do this. How much food, do you think a greenhouse hab can produce before the astronauts arrive?

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#24 2016-01-16 11:25:07

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 18,536

Re: Greenhouses

your closing question relys on what crop is grown as foot print yield volume of grown crop varies and each has differing measures for shelf life storage/preservation. That said we would need a table with crop,growing time, foot print for yield and storage method to shelf life.
Is there an article link?

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#25 2016-01-16 12:51:44

Tom Kalbfus
Banned
Registered: 2006-08-16
Posts: 4,401

Re: Greenhouses

SpaceNut wrote:

your closing question relys on what crop is grown as foot print yield volume of grown crop varies and each has differing measures for shelf life storage/preservation. That said we would need a table with crop,growing time, foot print for yield and storage method to shelf life.
Is there an article link?

A robot can harvest crops, and if we don't include pests and start with sterile soil, we won't have weeds, that would make the growing of crops fairly simple. As you know, it takes time to control a robot all the way from Earth, but then vegetables don't move much, and Mars is a natural freezer. You could bury the crops, they could last frozen for quite a long time, you can just keep growing more food, freezing it and burying it until the astronauts finally arrive, your growing area need not be that large at all! The plants are made out of Mars. Mars has all the elements needed to grow vegetables, water is a little scarce, but the soil is 5% water by weight, so robots would have to extract water from the soil, add it to the greenhouse, grow plants in it, harvest the plants and then bury the vegetables for storage, do it for long enough, and you can have many times the mass of the hab in buried vegetables. Some Mars scientists, who are looking for native Martian lifeforms, might not like this activity very much! I think at some point, we need to make a decision on whether we are to live on Mars, or study it. I think Earth life will not thrive on Mars as well as any native life that exists there. Where humans go, there will be contamination, but it seems to me, that what Mars has for an ecosphere right now, doesn't seem all that great.

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