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#1 Re: Life support systems » Mars Temperature and TEG » 2016-11-02 00:09:25

RobertDyck wrote:

That's also known as a Peltier device, named for the guy who discovered it: Jean Charles Athanase Peltier. NASA and the Russian space agency have already worked with this. They use it to convert heat from a RTG into electricity. Solid state, no moving parts.

Using temperature swings on Mars? Good idea. You would need a heat sink burried into the ground, then a Peltier device, then a heat sink with fins in the air. Computers use either aluminum or copper for their heat sink or heat pipes. Aluminum is cheaper, apparently copper conducts heat a little better. At least heat pipes are made of copper. But aluminum is cheaper. You would need a heat transfer engineer to work out how much power you could get.

But cosmic radiation? There's actually not much of that. In fact, over 90% of heavy ion galactic cosmic radiation is blocked by the atmosphere of Mars. At a low altitude location like Elysium Planetia, 98% is blocked. Light ions are not blocked as much, and the vast majority of proton radiation gets through. That means most of the radiation that reaches the surface of Mars is from the Sun, not cosmic. There is something called a beta-voltaic cell. It works similar to a photovoltaic cell aka solar cell, but beta-voltaic is designed to work with beta radiation. However, there's not much of that on Mars either. I don't know of anything that can use proton radiation. May as well stick to solar. But your first idea has promise, temperature change.

Thanks for the feedback and I am glad to learn that the atmosphere blocks so much of the radiation. If you were to pick a general location for the heat sinks where would it be?

#2 Life support systems » Mars Temperature and TEG » 2016-11-01 22:10:45

TonyTMarsBeginner
Replies: 3

“A Thermoelectric generator, or TEG (also called a Seebeck generator) is a solid state device that converts heat (temperature differences) directly into electrical energy through a phenomenon called the Seebeck effect (a form of thermoelectric effect). Thermoelectric generators function like heat engines, but are less bulky and have no moving parts.”

“Thermoelectric generators have a variety of applications. Frequently, thermoelectric generators are used for low power remote applications or where bulkier but more efficient heat engines such as Stirling engines would not be possible. Unlike heat engines, the solid state electrical components typically used to perform thermal to electric energy conversion have no moving parts. The thermal to electric energy conversion can be performed using components that require no maintenance, have inherently high reliability, and can be used to construct generators with long service free lifetimes. This makes thermoelectric generators well suited for equipment with low to modest power needs in remote uninhabited or inaccessible locations.”

I know that nuclear fission and solar power are probably the first choices for power on Mars, which got me thinking about good possible redundant systems once things get to be more established on the Red Planet. The things I like about the TEG is that they seem to have high reliability with no maintenance but they seem somewhat inefficient and more for low power uses which I imagine there might be on Mars.

A question I have is whether it is possible to exploit the large temperature swings on Mars and produce energy by use of TEG technology or some hybrid thereof?
Also, is there a way to collect falling cosmic radiation, harvest the heat off it, and couple it to TEG technology?

#3 Re: Science, Technology, and Astronomy » Books » 2016-10-30 21:15:27

RobertDyck wrote:

A couple years ago I published a list to Mars Society International » Amazon books - sponsor the Mars Society

Is there a specific topic? Do you want a shorter list? I would start with "The Case for Mars". That list is 2 years old, it has 2 editions: 1997 & 2011. Here is another book, originally published February 2013, this edition was published April of this year. Reviews are mixed, some people don't like the politics, and I haven't read it yet.
https://images-na.ssl-images-amazon.com/images/I/41Gbf2ivJJL._AC_US160_.jpg


Thanks, this looks like a good list.

#4 Science, Technology, and Astronomy » Books » 2016-10-30 15:32:16

TonyTMarsBeginner
Replies: 8

I was wondering if anyone could recommend any good books about Mars and the science that would be most applicable/useful for understanding Mars and Mars colonization etc. I was thinking that some sort of beginning physics but not sure where to start..

#5 Re: Life support systems » starving on five acres » 2016-10-30 15:23:13

JoshNH4H wrote:

It's a fair approximation to say that a mirror will reflect 90% of incident light if it's inside, 80% if it's outside and cleaned frequently, 70% if it's outside and cleaned infrequently.

You actually don't want to reflect too much light at your greenhouse.  They're probably going to be pretty much equatorial, and Mars receives 45% as much sunlight as Earth (plus the difference in atmospheric effects, so Mars does a bit better than that relative to Earth).  This means that just doubling the light levels means as much light as anywhere on Earth.

Having said that though, mirrors in exchange for more efficient use of greenhouse space (plants grow faster in higher light levels) is actually a pretty good trade.  You might want to have more light than earth in the greenhouses.


I was thinking about the green houses and wondering if it would work to put a few of them down in a canyon for protection against wind and so on and then thought about the CO2 then came across some interesting information:

"Cryptogamic covers are responsible for about half of the naturally occurring nitrogen fixation on land and they take up as much carbon dioxide as is released yearly from biomass burning. These new findings will help to improve global flux calculations and climate models, in which up to now the carbon and nitrogen balance of the cryptogamic covers have been neglected.

The roles that forests and oceans play in the climate and in the global exchange of oxygen, carbon, and nitrogen have been documented in numerous scientific studies. The importance of algae that grow on land, lichens, and mosses for the nitrogen and carbon fluxes and also for the carbon dioxide balance is normally not taken into consideration. This even though cryptogamic covers including the blue green algae (cyanobacteria) cover approximately 30% of soil surface that includes the surfaces of plants. Life forms that get their energy through photosynthesis, but don’t flower, belong to the cryptogams. They are found in all ecosystems, not just on roofs, trees, or walls. Cryptogamic covers, which consist of some of the oldest life forms on our Planet, are also found on cliffs and in soils in dry regions."

It might be an interesting idea to include some of these cryptogamic covers into your green houses somehow?

#6 Re: Life support systems » starving on five acres » 2016-10-29 23:29:43

JoshNH4H wrote:

There are some points where I agree with louis and some on which I disagree.  Land near a colony won't be quite free because of opportunity costs.  For example, if you decide to put a greenhouse on one sunny outcropping, you can't put a solar power facility there.  It is desirable for both of these to be close to living space.

Having said that, Mars has as much land as Earth and will have virtually no people.  Empty, unimproved land has very little opportunity cost or value.

What does have value is pressurized volume.  Even moreso than on Earth, indoor space will be expensive to build and maintain.  Indoor space will probably be at a pressure of about half an atmosphere.  This is 50,000 Newtons per square meter or about half a US ton per square foot.

One thing that matters is therefore going to be efficient use of internal space.  It was noted above that 50% of the area of Terran farms is used for human access.  By growing the crops in trays (whether they be hydroponic or aeroponic), 0% of the space could be used for human access and the crops could be on rails so that they move out of the way as needed for human access or harvesting.

The greenhouses will probably be circular in cross-section.  It might make sense to lift them up off the ground and point mirrors at them on the bottom. 

What will not make sense is to use grow lights.  The reason why is systemic inefficiency.  Here's a representative idea:

Solar panels or concentrated solar power plants will be about 20% efficient at converting sunlight into electrical energy
LEDs will be maybe 20% efficient

Put together, this is a systemic efficiency of 4%.  This means you need 25 times as much area in power generation plants as you would in greenhouse.  There will also be some losses if you're using mirrors but not as much, so perhaps 20 times as much power generation area as mirror area.

I just said that land area isn't expensive, so you would think this would be a good trade.  But think about what this really means:  Instead of building a greenhouse, you're building power plants.  Louis likes to claim that electrical energy will be abundant on Mars, but "abundant" and "free/cheap" are not the same thing.  In fact, we know from economics that as demand goes up price also tends to go up.  8000 square feet is about 800 square meters.  At Earthlike levels of illumination, each square meter will see 17.3 MJ (5 kWh) of light energy per day.  This adds up over time to a lot of wasted energy for no real reason.

Louis and I have discussed this before and we didn't get much of anywhere.  I believe that his approach on this topic is wrong and I would like to push back here so that you all can at least see the counterpoint.

Bouncing light off mirrors is an interesting idea for greenhouses and other applications as well. I wonder how the light intensity is affected by distance and number of bounces, for instance could mirrors be used on a canyon side to bounce light to another mirror on canyon bottom and back up through the floor of a green house, then bounced throughout the structure, would the light keep decreasing?

#7 Re: Life support systems » starving on five acres » 2016-10-29 13:26:49

RGClark wrote:
TonyTMarsBeginner wrote:

I took a tour of Mesa Verde Ruins years ago and the tour guide explained how the inhabitants farmed and on what crops they subsisted on as well as other interesting things. One thing that I found especially interesting is the story of how he and a friend decided  to try to live only upon what they grew on their land. Each of the men had five acres and a water well and each worked together and rotated crops etc. Sadly, they both had to give up as they could not grow enough food to live upon. He made a point that many people had to grow different things and then share back and forth etc. within the Mesa Verde Settlement. If ten acres of prime land and endless water with clean air produces such dismal results how much harder will it be to grow enough food on Mars.

Did a web search on how much land to sustain a person and found this:


How Much Land Does It Take To Be Self-Reliant?
November 15, 2012 By M.D. Creekmore

The research to the answer to that question was started back in the 70’s by a man named John Jeavons.  The “Bio-Intensive” method Jeavons developed has been implemented worldwide to alleviate hunger and malnutrition.  Jeavons has a model for a vegetarian diet and the short answer is summarized as approximately 8,000 sq.ft. for a complete diet for one person (you need 4,000 sq/ft. of actual growing space and at least 4,000 sq.ft. for pathways and access).  That is also assuming you have four growing seasons per year, and your harvest is 100% (no failures).
For reference, an acre is 43,560 sq.ft.  So in a more southern climate, you could theoretically support about 5 people per acre.  But life is never that perfect.  My personal experience is that 2 acres in a mild temperate region will completely wear you out and is enough room to comfortably support a family of four with a variety of food sources such as gardens, orchards, small livestock, and wild crafting.  You can still do a lot in less area, and of course, everyone always wants more.

http://www.thesurvivalistblog.net/how-m … f-reliant/


Perhaps the Mesa Verde land wasn't very arable or those working it weren't experienced farmers.

  Bob Clark

I failed mention in my post that they wanted to use the same technology as the Native Americans of the area and not modern equipment or fertilizers etc., which may or may not carry over to Mars..

#8 Re: Life support systems » starving on five acres » 2016-10-29 13:19:41

JoshNH4H wrote:

There are some points where I agree with louis and some on which I disagree.  Land near a colony won't be quite free because of opportunity costs.  For example, if you decide to put a greenhouse on one sunny outcropping, you can't put a solar power facility there.  It is desirable for both of these to be close to living space.

Having said that, Mars has as much land as Earth and will have virtually no people.  Empty, unimproved land has very little opportunity cost or value.

What does have value is pressurized volume.  Even moreso than on Earth, indoor space will be expensive to build and maintain.  Indoor space will probably be at a pressure of about half an atmosphere.  This is 50,000 Newtons per square meter or about half a US ton per square foot.

One thing that matters is therefore going to be efficient use of internal space.  It was noted above that 50% of the area of Terran farms is used for human access.  By growing the crops in trays (whether they be hydroponic or aeroponic), 0% of the space could be used for human access and the crops could be on rails so that they move out of the way as needed for human access or harvesting.

The greenhouses will probably be circular in cross-section.  It might make sense to lift them up off the ground and point mirrors at them on the bottom. 

What will not make sense is to use grow lights.  The reason why is systemic inefficiency.  Here's a representative idea:

Solar panels or concentrated solar power plants will be about 20% efficient at converting sunlight into electrical energy
LEDs will be maybe 20% efficient

Put together, this is a systemic efficiency of 4%.  This means you need 25 times as much area in power generation plants as you would in greenhouse.  There will also be some losses if you're using mirrors but not as much, so perhaps 20 times as much power generation area as mirror area.

I just said that land area isn't expensive, so you would think this would be a good trade.  But think about what this really means:  Instead of building a greenhouse, you're building power plants.  Louis likes to claim that electrical energy will be abundant on Mars, but "abundant" and "free/cheap" are not the same thing.  In fact, we know from economics that as demand goes up price also tends to go up.  8000 square feet is about 800 square meters.  At Earthlike levels of illumination, each square meter will see 17.3 MJ (5 kWh) of light energy per day.  This adds up over time to a lot of wasted energy for no real reason.

Louis and I have discussed this before and we didn't get much of anywhere.  I believe that his approach on this topic is wrong and I would like to push back here so that you all can at least see the counterpoint.

When I read this I had a question arise. Can we breath the air in greenhouses without any supplementation and also will the oxygen build up to unsafe levels? If it does would we have to vent the oxygen and if this is the case then won't we loose the nitrogen and I read in other posts that Mars really needs nitrogen? If there is a way to do these things would it use up a lot of energy?

#9 Re: Life support systems » starving on five acres » 2016-10-28 23:17:47

louis wrote:

I have to say Tony that I don't envisage canyons as being a first stop for the Mars colony. Personally I think it goes:

1. Lander craft

2. Inflatable home habitats.

3. Cut and cover habitats (dig a trench and put a roof over).

4. Tunnels and sandstone enclaves.

5.  Glass or perspex domes.

6. Canyons.


So this is where I need some clarification, 1-5 to me seem like a logical progression that takes place while food is being dropped off periodically and people are staying but for fairly short durations, then returning back to earth and so on until number six happens and people actually stay for extended periods of time like 1-5 years until they truly know the long term effects of Mars on the human body and if all is well then people start making the red planet home. But from what I have been reading in various posts it seems like the plan is more like 2-3 people are already making Mars home. When do you see (in the above progression)people actually self reliant and living permanently on Mars? And at what point is there enough redundant life support on Mars in all various forms that people don't die if a rocket doesn't make a return trip on time?

#10 Re: Life support systems » starving on five acres » 2016-10-28 18:37:40

louis wrote:

"politicians, money, time, and peoples' fear" - Yep you are right to consider those the enemy! 

I agree a small lunar base would have completely changed our perspective on exploring the solar system.  NASA took a  huge wrong turn when it abandoned the Moon.

Personally, I feel we can't be that far from the era of lunar tourism...in fact if Musk was purely focussed on making money rather than realising an historic undertaking, he would probably be concentrating that.

I really admire Musk's vision and technical ability. But I do question his understanding of people, of group dynamics, of politics, of organising people with a multitude of needs and wants!  You can't simply "dump" 50,000 people on Mars every two years - supposedly on a no-return basis.  There has to be some sort of selection criteria, and I think as soon as you look at those criteria, you realise finding 50,000 people every two years who meet the criteria and are willing to give up their lives on Earth is going to be incredibly difficult....and I suspect impossible.  You can probably easily find 50,000 desperadoes or mentally ill people or religious fanatics or extremely poor and uneducated  people or people who overestimate their abilities or romantics...but 50,000 people with the real skills you need, the depth of character and the willingness to say goodbye to life on Earth and to the chance to raise a family? I don't think so. These people will all need extensive training remember!  Quality training never comes cheap - and that seems to be something Musk hasn't factored in.

Even if you found 50,000 with the right skills and personality match, you will face huge problems of organisation on a planet where minutely controlled life support is essential.

I agree with you there. I think it would be a good idea to drop off all the materials and tools needed to build one of those canyons you are talking about as well as an underground bunker/habitat that was connected to the green canyon. Instead of 50,000 people they ought to send a hundred contractors and a handful of scientists and everything that these people would need to get a safe and strong permanent structure built first. Then I think the realistic settlement process could safely begin. I know that the preliminary stuff would have to happen first, I just think that the above ought to happen before all the people get dumped there.

#11 Re: Life support systems » starving on five acres » 2016-10-28 14:07:21

louis wrote:

More generally - I think you are being way too pessimistic about farming on Mars. 

I personally don't think we will begin with dome farming in natural light.  So, talking in terms of "acres" isn't helpful I think.

Basically farming comes down to seeds, nutrient-rich growing medium, water and energy (from the Sun or artificial lighting). If you get those four right, you literally cannot fail (although I suppose we should add that absence of gravity can pose challenges...though everything suggests growing plants in 0.38 Earth gravity should be OK).

I think we will opt for artificially lit indoor farms.  We may use soil or we may use hydroponic (or similar) techniques.

For the first few missions we may import the soil and nutrient solutions. Then we will be making compost, adding in food waste and human faeces to enrich the soil.

After a few years, we will probably  be manufacturing soil on Mars - crushing rock to the right grades, mixing in Mars sand and Mars clay, introducing microbes, nutrients  and analogues for plant matter.

For indoor farming, the only structure we need is a pressurised space.  So use the most efficient methods to do that. Maybe carving out chambers in sandstone would work. Within those chambers you can have several shelves where plants are grown in soil trays or are growing hydroponically using nutrient rich water solutions. So, within any one area you are doubling, tripling or more the "space" being used as you are growing the food on several layers.  Lighting would come from LEDs producing an analogue for natural sunlight and working on timers.  The air might be enriched with above normal levels of CO2 to encourage growth.

Each plant type would be given exactly the right nutrients, light, and water etc to ensure optimal development.

Here is an interesting link showing how an indoor farm actually works on Earth.

https://www.youtube.com/watch?v=H7h_qC73In0&app=desktop

Indoor farms currently appear to grow mostly salad crops but I think that is only because of commercial considerations i.e. they can compete economically with organic produce grown naturally outside. Those sorts of costs considerations will not apply on Mars where energy and land will in essenece be freely available.

So I am very optimistic about farming on Mars.  I don't anyone will be starving there!





You are right, I was having a fairly pessimistic day yesterday. I do believe in the farming capacity of Mars and especially so with your ideas on canyon habitats. The use of gravity and water flow and vertical farming and protection from canyon walls all makes sense to me, in fact this idea of canyon habitat seems sustainable and safe. Even artificial waterfalls and canals would make engineering sense with your concept.

I still have pessimism though in regards to politicians, money, time, and peoples' fear. It's kind of like the moon missions and how they fizzled out even in the face of the peoples enthusiasm. A small moon base as a research or emergency outpost for scientists, astronauts, or tourists would have been really cool and could have been done relatively easy and inexpensively and much could have been learned, and gained. And I am not advocating for the moon I like Mars, I am just wondering if this pattern is going to play out on Mars..after a few manned missions the politicians and powers that are just pull the plug and like the people during the space race their dreams get thrown aside.

I sense that Elon Musk has got it right with the large loads being taken to Mars right from the beginning, so that serious results can be seen quickly, and excitement can grow. I also think that there needs to be some sort of reason found be it rare platinum, super conductive metals, new materials or whatever to further the case for Mars in the minds of those who hold the purse strings. And the sooner in the missions time line this is figured out the better.

#12 Life support systems » starving on five acres » 2016-10-28 01:53:07

TonyTMarsBeginner
Replies: 34

I took a tour of Mesa Verde Ruins years ago and the tour guide explained how the inhabitants farmed and on what crops they subsisted on as well as other interesting things. One thing that I found especially interesting is the story of how he and a friend decided  to try to live only upon what they grew on their land. Each of the men had five acres and a water well and each worked together and rotated crops etc. Sadly, they both had to give up as they could not grow enough food to live upon. He made a point that many people had to grow different things and then share back and forth etc. within the Mesa Verde Settlement. If ten acres of prime land and endless water with clean air produces such dismal results how much harder will it be to grow enough food on Mars. I would guess that to just be able to plant and harvest on five acres on Mars one would need a massive amount of infrastructure in place first. The infrastructure I suppose could happen but not with just a handful of scientists or astronauts. Masons, Electricians, Plumbers, AC, Steel workers, Heavy Equipment Operators, and much more would need to make the trip as well. Supplies and equipment would have to be in place and a more sustainable and safe habitat would have to be constructed within 40-50 days before food shortages or air problems began. Reserves of air, water, food, first aid, and more would need to be stock piled and in quantities well  above estimates in case something goes wrong for each building phase etc. and for all contractors, astronauts, scientists, and so on. Cost to build a decent sustainable, safe, and large enough habitat that would allow for a proper foothold (within the next 50-60 years), probably at least 4-6 billion here on earth, but on Mars I would estimate 5 trillion on up. If a small manned mission that is basically a short stay and minimal exploration, costs 4-5 hundred million it's easy to extrapolate out from there. Small amounts of work done by small amounts of people done over long periods of time on one seriously inhospitable planet probably doesn't equate to very good productivity/results and I would think that the short visit/stay cycle would never be overcome. Essentially stuck starving on five acres.

#13 Re: Life support systems » nanoparticles and steam » 2016-10-26 19:23:42

Good points, cost to outcome probably doesn't make sense and pressurized rovers if built right could take care of most scenarios.

#14 Life support systems » nanoparticles and steam » 2016-10-26 18:14:53

TonyTMarsBeginner
Replies: 5

"A new, extremely black material can turn water into steam using only sunlight, without the need to bring the water to a boil. Made of gold nanoparticles tens of billionths of a meter wide affixed to a scaffold pocked with tiny channels, or “nanopores,” the material is a deep black color because it reflects very little visible light. It is 99 percent efficient at absorbing light in the visible spectrum and parts of the infrared spectrum, researchers report April 8 in Science Advances.

Thanks to its highly porous structure, the material floats on the surface of water, allowing it to soak up the sun’s rays. When light of a certain wavelength hits a gold nanoparticle inside one of the nanopores, it stirs up the electrons on the surface, sloshing them back in forth in an oscillation known as a plasmon. These plasmons produce localized, intense heating, which vaporizes the water nearby.

The wavelength of light that excites a plasmon depends on the size of the nanoparticle. So in order to take advantage of as much of the sun’s output as possible, the group interspersed a variety of sizes of gold nanoparticles in the pores, which could therefore absorb a range of wavelengths."

I was wondering if a warm suit with impregnated nanoparticles would be a good idea or not? Maybe an emergency suit or an addition to something else. It might be a way to combat the extreme cold.

https://www.google.com/url?sa=t&rct=j&q … ssu6UAwIDw

#15 Re: Terraformation » Tharsis Volcanoes and Cement » 2016-10-26 10:16:15

Tom Kalbfus wrote:

I wonder what this subject has to do with terraforming? We don't need to terraform Mars to make cement. We don't need to make cement to terraform Mars either. If the Tharsis Volcanoes have the stuff needed to make cement, great! But I don't get why this thread comes under the heading of Terraformation. Just thought I'd mention this.


“terraform: (especially in science fiction) transform (a planet) so as to resemble the earth, especially so that it can support human life.”


Radiation

“The depth of penetration for a given photon energy is dependent upon the material density (atomic
structure). The more subatomic particles in a material (higher Z number), the greater the likelihood
that interactions will occur and the radiation will lose its energy. Therefore, the denser a material is
the smaller the depth of radiation penetration will be. Materials such as depleted uranium, tungsten
and lead have high Z numbers, and are therefore very effective in shielding radiation. Concrete is
not as effective in shielding radiation but it is a very common building material and so it is commonly
used in the construction of radiation vaults.
Most designers and builders today are familiar with the advantages of using very high density
concretes for radiation shielding. Not so well known is the excellent economy which can result from
the use of normal site cast concretes with locally available aggregates when space and other factors
do not absolutely demand that the desired protection be achieved within minimum dimensional
limits. The effectiveness of any biological shielding material is related only to its mass and concrete
has an obvious advantage in this highly specialized field of construction because of its exceptionally
low cost per pound.”


Benefits of concrete
“Concrete has a number of performance characteristics that can improve the sustainability performance of a building or structure.”
 
Acoustics
“The issue of sound insulation and acoustic performance of homes has grown in importance, primarily due to the growing demand from government for increased density of urban dwellings. The number of complaints about noise has risen due both to this closer proximity and the new demands placed on housing (e.g. entertainment systems). For this reason, the UK Building Regulations Part E now requires improved sound insulation.”
Flooding
“New building works within areas of flood risk are only permitted in exceptional cases where the risks are managed and adequate flood defense measures and/or flood resistant construction techniques are adopted. The type of floor construction is an important consideration.”
Fire
“Concrete does not burn: it cannot be 'set on fire' like other materials in a building and it does not emit any toxic fumes when affected by fire. It will also not produce smoke or drip molten particles. For these reasons, in the majority of applications, concrete can be described as virtually 'fireproof'. Concrete's inbuilt fire resistance maintains airtight construction that stops smoke spreading, and the ability to maintain the building's strength during a fire.”
Thermal mass and operational energy efficiency
“Thermal mass basically describes the ability of construction materials to absorb, store and release heat; a useful property which helps regulate the temperature in buildings. Heavyweight materials such as concrete provide a high level of thermal mass, and this is often measured in terms of something called 'admittance' which has units of W/m2 K.”
Low carbon construction
“Sustainability is more than simply about carbon, and this is recognised in codes and assessment tools. However CO2 emissions, associated with materials, manufacture, construction, operation and end of use, is an important parameter and the cement and concrete industry is investing hugely in developing and enabling construction solutions that reduce whole life CO2 emissions as well as embodied CO2.”
Durability and long-life
“The full structural capacity of a masonry or concrete wall, with its considerable reserve of strength and ability to accommodate future changes, far exceeds design requirements. It is this inherent robustness that has enabled traditionally built houses to cater for increased loads emanating from alterations and adaptation. Their strength also facilitates the introduction of concrete upper floors which provide clear spans between external walls and will support internal masonry walls. All internal walls below become non-load bearing, producing a design where the layout can be altered to cater for future changes in living requirements, so satisfying the government's requirement for 'lifetime homes'.”

Concrete would speed the time of construction of a durable and safe habitat, working in irradiated environments is bad, working in a concrete structure without the hindrance of a space suit or radiation exposure would help in terraforming efforts and is good. Terraforming and concrete go together like cookies and milk.

#16 Re: Terraformation » Tharsis Volcanoes and Cement » 2016-10-26 07:55:38

louis wrote:

Interesting discussion. Locating reserves of calcium carbonate (or finding ways of making it) will be crucial to industrial development on Mars.

That said, I am not sure we need cement to make a canyon project work.

On earth we already use subterranean reservoirs to store gas under pressure.  Reading up on the subject, it appears these reservoirs need to be topped with impermeable cap rock.  Examples given of good impermeable cap rock are sandstone, unweathered clay and granite, all of which exist in good quantities on Mars I believe.

https://en.wikipedia.org/wiki/Permeabil … nduit_flow

Even with the great pressure differential on Mars, I think we can assume that we could, without the need to seal with cement,pressurise a canyon on Mars with the right rock and not suffer significant losses of air. Personally, from an aesthetic point of view, I think that will be much nicer for humans as well. It will be good for them to have that hand hold on real natural rock, and once we apply some (Mars-manufactured*) soil and so on crevices and rock ledges, we can then grow a range flowering plants, bushes, with trees being grown in the canyon bottom.

Sandstone sounds a bit counterintuitive but then that might confirm what I have always suspected: that with that sort of rock, the escape of gas itself drags tiny particles into escape vent channels which then become effectively blocked and impermeable.

* I've researched before how to manufacture soil - a very interesting subject in itself.  It's eminently doable - crushing rock and so on, introducing the right microbes, using human and food waste - though we may need to import some fertiliser to begin with.  Mention of microbes does however raise a risk factor.  Working in garden centres among so many plants does increase your risk of serious lung and other infections.  We would want to have a full health risk assessment for a canyon environment.  One example - although running water is attractive, we would probably wish to avoid spray effects - creating the possiblity of aerosol transmission of bugs.  Maybe your canyon "river" would, sadly, need to be chlorinated and any fish kept in isolated glass tanks.


article-2267504-17212EB3000005DC-781_634x663.jpg

This might have been discussed before but here is a man who hasn't watered his plant for 40 years! Would it be possible to make a bunch of these and hang them in the canyon at various places and have some greenery that doesn't have to be watered, leaving the water for other trees, plants, and aforementioned projects.

It might have been explained in other posts somewhere but what is the quickest way to make the soil you are talking of minus the radiation? And a side note have you heard of the red soil from South America that regenerates and grows and has 2-3 hundred percent crop increases? Maybe it could be replicated on Mars or transported there into the canyons, once established maybe portions could be transported other places?

#17 Re: Terraformation » Tharsis Volcanoes and Cement » 2016-10-25 08:07:47

Void wrote:

Oh, and here is another potential favorable factor.
Glaciers on Volcano's on Mars.
https://en.wikipedia.org/wiki/Glaciers_on_Mars

Glaciers on volcanoes[edit]
Many supposed glaciers have been observed on some of large Martian volcanoes. Researchers have described glacial deposits on Hecates Tholus,[64] Arsia Mons,[65] [66] Pavonis Mons,[67] and Olympus Mons.[68]
Scientists see evidence that glaciers exist on many of the volcanoes in Tharsis, including Olympus Mons, Ascraeus Mons, and Pavonis Mons.[69][70] Ceraunius Tholus may have even had its glaciers melt to form some temporary lakes in the past.[71][72][73][74][75][76][77]

So, that is something that has been previously overlooked.
-Volcanic Ash
-Lava Tubes
-Glaciers???

Of course you might have to bring in your Calcium Carbonate.

-Geothermal Power???  (Giant Volcano's after all, possibly still active to a degree).

mushroom.png

"Volcanogenic massive sulfide ore deposits, also known as VMS ore deposits, are a type of metal sulfide ore deposit, mainly copper-zinc which are associated with and created by volcanic-associated hydrothermal events in submarine environments.
These deposits are also sometimes called volcanic-hosted massive sulfide (VHMS) deposits. The density generally is 4500 kg/m3. They are predominantly stratiform accumulations of sulfide minerals that precipitate from hydrothermal fluids on or below the seafloor in a wide range of ancient and modern geological settings. In modern oceans they are synonymous with sulfurous plumes called black smokers.
They occur within environments dominated by volcanic or volcanic derived (e.g., volcano-sedimentary) rocks, and the deposits are coeval and coincident with the formation of said volcanic rocks. As a class, they represent a significant source of the world's copper, zinc, lead, gold and silver ores, with cobalt, tin, barium, sulfur, selenium, manganese, cadmium, indium, bismuth, tellurium, gallium and germanium as co- or by-products."


Mars_topography.jpg

Do you think that the Volcanoes of Tharsis and there relatively close proximity to the ancient sea could produce massive sulfide deposits, I know that it's a guess until the area is actually explored but I suppose that there is a possibility of many ores and in large quantities that would be useful for building, technology, and other applications. And they would be right in the same vicinity as all of the  other resources: narrow canyons, concrete, water, and all the others you've mentioned. Less oxygen and time expenditure.

"Iron ores[1] are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, deep purple, to rusty red. The iron itself is usually found in the form of magnetite (Fe
3O
4, 72.4% Fe), hematite (Fe
2O
3, 69.9% Fe), goethite (FeO(OH), 62.9% Fe), limonite (FeO(OH).n(H2O)) or siderite (FeCO3, 48.2% Fe)."

"Ores containing very high quantities of hematite or magnetite (greater than ~60% iron) are known as "natural ore" or "direct shipping ore", meaning they can be fed directly into iron-making blast furnaces."

Hematite has already been found in two locations on Mars and I would guess that it will be found all over Mars just as it is on earth, it would be interesting if it was also found nearby the above mineral in association with a lot of iron for steel manufacturing.

#18 Terraformation » Tharsis Volcanoes and Cement » 2016-10-24 15:59:30

TonyTMarsBeginner
Replies: 14

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Limestone

“The key fact about limestone on Earth is that nearly all of it is made up of the shells of marine life, specifically single-celled plankton. Limestone forms as billions of generations of plankton live and die near the ocean surface where sunlight penetrates. As each old cell dies, its living matter rots away and its remaining little shell of calcium carbonate drifts down to the bottom. They mount up like snow, as millennia pass, and the older plankton snowfalls compress under the younger, eventually hardening to solid rock.”

Calcium Carbonate on Mars
“The discovery of calcium carbonate on Mars conjures up images of red, alien seas filled with life. Perhaps if we’re lucky some of them scuttled on tripod legs. I hope for H. G. Wells’ sake they did. But the reality is probably not so romantic. Limestones on Earth are mostly from plankton, but a few formed by direct chemical precipitation from water, without the involvement of life. Such chemical limestone deposits are usually associated with evaporite rocks, which form just like their name sounds; by water drying up. Inland seas and lakes sometimes dry away as a result of changing climate, and leave behind all their salts as layers of different minerals, including rock salt, gypsum, borax, and limestone. When harsh alkali winds blow across Earth deserts, the alkali comes from windblown evaporite dust and grit.”
“Carbonates found by Phoenix might come from either a big wet sea, or a little dying sea. A little dying sea is more likely, especially considering that Phoenix also found evidence of perchlorates in the sand. Perchlorate is a highly oxidized form of chlorine, and is the active ingredient in laundry bleach. Perchlorates contain chlorine, which is also a component of sea salt (sodium chloride). A drying sea would lay down layers of rock salt and carbonate, more or less adjacent physically. Exposed for ages at the Martian surface, chloride salts would naturally oxidize to perchlorate under the relentless, unfiltered glare of solar and cosmic radiation. Limestones laid down by plankton don’t usually contain any chloride salts.”

Concrete
“Concrete is a composite material which is made up of a filler and a binder. The binder (cement paste) "glues" the filler together to form a synthetic conglomerate. The constituents used for the binder are cement and water, while the filler can be fine or coarse aggregate.”
“Cement, as it is commonly known, is a mixture of compounds made by burning limestone and clay together at very high temperatures ranging from 1400 to 1600.”
“The production of portland cement begins with the quarrying of limestone, CaCO3. Huge crushers break the blasted limestone into small pieces. The crushed limestone is then mixed with clay (or shale), sand, and iron ore and ground together to form a homogeneous powder.”



Roman Concrete

“By analyzing the mineral components of the cement taken from the Pozzuoli Bay breakwater at the laboratory of U.C. Berkeley, as well as facilities in Saudi Arabia and Germany, the international team of researchers was able to discover the “secret” to Roman cement’s durability. They found that the Romans made concrete by mixing lime and volcanic rock to form a mortar. To build underwater structures, this mortar and volcanic tuff were packed into wooden forms. The seawater then triggered a chemical reaction, through which water molecules hydrated the lime and reacted with the ash to cement everything together. The resulting calcium-aluminum-silicate-hydrate (C-A-S-H) bond is exceptionally strong.”
“By comparison, Portland cement (the most common modern concrete blend) lacks the lime-volcanic ash combination, and doesn’t bind well compared with Roman concrete. Portland cement, in use for almost two centuries, tends to wear particularly quickly in seawater, with a service life of less than 50 years. In addition, the production of Portland cement produces a sizable amount of carbon dioxide, one of the most damaging of the so-called greenhouse gases. According to Paulo Monteiro, a professor of civil and environmental engineering at the University of California, Berkeley, and the lead researcher of the team analyzing the Roman concrete, manufacturing the 19 billion tons of Portland cement we use every year “accounts for 7 percent of the carbon dioxide that industry puts into the air.”
“In addition to being more durable than Portland cement, argue, Roman concrete also appears to be more sustainable to produce. To manufacture Portland cement, carbon is emitted by the burning fuel used to heat a mix of limestone and clays to 1,450 degrees Celsius (2,642 degrees Fahrenheit) as well as by the heated limestone (calcium carbonate) itself. To make their concrete, Romans used much less lime, and made it from limestone baked at 900 degrees Celsius (1,652 degrees Fahrenheit) or lower, a process that used up much less fuel.”

Roman Volcanoes and Ash

“Mount Etna is one of the most active volcanoes in the world and is in an almost constant state of activity. The fertile volcanic soils support extensive agriculture, with vineyards and orchards spread across the lower slopes of the mountain and the broad Plain of Catania to the south. Etna is an active basaltic volcano, the activity of which is dominated by effusive eruptions that represent a continuous threat to a large populated area.”

“Mt. Fuji and Mt. Etna, for example, are dominanted by basaltic lava flows, whereas Mt. Rainier is dominated by andesitic lava, Mt. St. Helens by andesitic-to-dacitic pyroclastic material, and Mt. Lassen by dacitic lava domes.”




Mars and Earth Volcanoes
“The most common form of volcanism on the Earth is basaltic. Basalts are extrusive igneous rocks derived from the partial melting of the upper mantle. They are rich in iron and magnesium (mafic) minerals and commonly dark gray in color. The principal type of volcanism on Mars is almost certainly basaltic too.[12] On Earth, basaltic magmas commonly erupt as highly fluid flows, which either emerge directly from vents or form by the coalescence of molten clots at the base of fire fountains (Hawaiian eruption). These styles are also common on Mars, but the lower gravity and atmospheric pressure on Mars allow nucleation of gas bubbles (see above) to occur more readily and at greater depths than on Earth. As a consequence, Martian basaltic volcanoes are also capable of erupting large quantities of ash in Plinian-style eruptions. In a Plinian eruption, hot ash is incorporated into the atmosphere, forming a huge convective column (cloud). If insufficient atmosphere is incorporated, the column may collapse to form pyroclastic flows.[13] Plinian eruptions are rare in basaltic volcanoes on Earth where such eruptions are most commonly associated with silica-rich andesitic or rhyolitic magmas (e.g., Mount St. Helens).”

“The largest and most conspicuous volcanoes on Mars occur in Tharsis and Elysium regions. These volcanoes are strikingly similar to shield volcanoes on Earth. Both have shallow-sloping flanks and summit calderas. The main difference between Martian shield volcanoes and those on Earth is in size: Martian shield volcanoes are truly colossal. For example, the tallest volcano on Mars, Olympus Mons, is 550 km across and 21 km high. It is nearly 100 times greater in volume than Mauna Loa in Hawaii, the largest shield volcano on Earth. Geologists think one of the reasons that volcanoes on Mars are able to grow so large is because Mars lacks plate tectonics. The Martian lithosphere does not slide over the upper mantle (asthenosphere) as on Earth, so lava from a stationary hot spot is able to accumulate at one location on the surface for a billion years or longer.”
“On October 17, 2012, the Curiosity rover on the planet Mars at "Rocknest" performed the first X-ray diffraction analysis of Martian soil. The results from the rover's CheMin analyzer revealed the presence of several minerals, including feldspar, pyroxenes and olivine, and suggested that the Martian soil in the sample was similar to the "weathered basaltic soils" of Hawaiian volcanoes.[17] In July 2015, the same rover identified tridymite in a rock sample from Gale Crater, leading scientists to believe that silicic volcanism might have played a much more prevalent role in the planet's volcanic history than previously thought."


I hope this hasn't already been discussed too often but I have a few questions and comments. I was reading some various posts by Louis, Void, KBD512, and others about walling off narrow canyons and using them for habitation and other purposes and I found these ideas really practical and ingenious. I think that some drawings and plans ought to be designed and discussed more. Anyway I started thinking about walls and supports and foundations, then started thinking about concrete (which I haven't checked out yet on the posts but imagine have been already discussed) and I have posted some of the info above, and where to make it. Would the narrow canyons by the Volcanoes in the above picture work for what you are talking about? And do you think that the type of calcium carbonate on Mars would work for cement if not would the volcanic ash from Tharsis work for making the cement? And as a side note would any of the volcanic soils be good for growing crops due to radiation?

#19 Re: Terraformation » core issues » 2016-10-23 15:07:36

Void wrote:

Tony,


Obviously first come nomads who live in flying tin cans.

Then per "Louis" it is hoped that some researchers may be sponsored by universities, and governments, to do greater discovery of the ground truth of Mars.

From the beginning there will be pressure to make material objects and substances insitu, from the environment of Mars itself.

As the technological culture would develop, it would become possible in the end I would hope for humans to master the polar ice caps of Mars, and begin the implementation of a Martian ecology.

In the case of the southern polar ice cap which is elevated, you could have ice covered canals that run downhill by gravity feed and provide large quantities of water to cities closer to the equator.

Have any Universities or Governments been asked to sponsor up front before the first manned missions? Not to assume too much but I would think that many would donate moneys ahead of settlement, also I would think that a country like Korea who have invested trillions into their robotics programs would love a chance to flex their robotic muscles by donating a robot to the missions, of course SpaceX would have to have to final say on what they would carry within their parameters but it would be interesting to ask around if it hasn't already been done.

Do the polar ice caps regenerate or once they're gone they're gone, and if this is the case how much time and usage would there be?

#20 Re: Terraformation » core issues » 2016-10-23 12:30:17

Void wrote:

Shelter.

While humans could shelter in the waters of artificial ice covered lakes, and could have greenhouses there that were artificially lit, I prefer to look for a place for cities much closer to the equator.

I am looking at sandstone, and as an example Mt. Sharp.  Curiously.

I'm done.


Mt. Sharp seems to have several resources in the general vicinity like almost perfectly formed sedimentary slabs for walls and flooring etc, the depression around the mountain could hold water, and with 18,000 feet or so there is an opportunity for good water pressure, the landing sites in the area seems relatively good even if it was overshot some, and it looks like level ground up to the ice-caps in regards to canals or piping, the Hematite might prove useful maybe even indicative of gold, there seems to be academic interest in the area too, all in all it seems like a good contender with possibilities. Are you thinking along the lines of the Egyptian tomb builders how they followed fractures and faults for easier digging?

The Syria Planum region is an area that I am looking forward to learning more about once they get there, it might not have so many readily available resources like Mt. Sharp, though I find myself intrigued by the highlands.

#21 Re: Terraformation » core issues » 2016-10-22 23:34:10

Void wrote:

Tony,

I will only respond in part.  I am sure others can express more for you as well, or they can also correct or oppose my opinion.

I do not think I believe in the necessity of a dynamic magnetic field anymore.

We have two apparent examples of worlds which can hold an atmosphere with an induced magnetic field.  Venus, and I think perhaps also Pluto (Perhaps).

Recent literature I have read indicates that Mars may have never had a complete magnetic field, and that the dynamic magnetic field it did have was for the most part in on hemisphere.  The north I think.

So, to me it is beginning to look like it is a disaster to a planet like Mars to have a mixed situation, where in part it has a dynamic magnetic field, and also an induced magnetic field in other places.

Currently it has a fossil magnetic field, mostly in one hemisphere, which is weak, and that situation helps the solar wind lift off big chunks of atmosphere.

As for restarting the previous magnetic field, that might not be an improvement.  It still might be partial, which apparently actually contributes to atmospheric stripping by the solar wind.


Very interesting information some of these things are kind of counterintuitive and its good to share others insights. After reading some of the terraforming posts I kind of think that a lot of the ideas could be applied to an underground mini city with its own atmosphere, magnetic field, soil formation, various processes and cycles, and much more. Do you favor a particular method of atmosphere enhancement like a quick nuke blast scenario or a far into the future type situation with not yet developed technologies or a hybrid plan like small terraforming projects or no terraforming at all?

#22 Terraformation » core issues » 2016-10-22 22:12:33

TonyTMarsBeginner
Replies: 12

I was wondering about the Mars core and how it ties into terraforming. Is a spinning core essential to all the other live planet processes and cycles for example the water and air cycles or soil and atmosphere creation etc? For the environment to be self sustaining is a spinning core a necessity? Did Mars have a spinning core, and if so how did it stop, was it a major impact and if this is the case would another impact stop the core again, if it was somehow started again? Another interesting question is if it is possible to start the core with out blowing up or damaging any settlements in the process and what are these logistics, blast off a nuke for atmosphere and/or core spin and then colonize or the reverse etc, I think Zubrin wants to get there first and work out atmosphere stuff later but maybe the first trip should be a nuclear/atmosphere enhancement? I don't know if it has been discussed yet but I think that for long term habitation a central issue is going to end up being how to detect and stop impacts from ruining all of the hard gains made, be it settlements, mines, or the starting of the core for that matter. This I think is going to be paramount to any serious surface habitation and probably for underground living as well, though probably not important if habitation is always going to be on the small scale or Mars is just going to be visited for short stays every so often, or Mars is just going to be robot central.

#23 Re: Life support systems » Lift off and touch down » 2016-10-22 01:29:45

kbd512 wrote:

For vehicles, lattice-enabled nuclear reactions (LENR's) produce very little radiation that human occupants would require shielding to survive, even though they transmute the fuel, and they still produce incredible amounts of heat.  Gasoline is 34.2MJ/l.  LENR is 342,000MJ/l.  So, no matter which nuclear technology is utilized, you're always going to achieve higher energy density with nuclear technologies compared to solar technologies, partly because solar panels only produce maximum output for 6 hours out of a 24 hour day, partly because batteries are heavy and energy storage densities are quite low, and mostly because the energy released from nuclear reactions of any kind (fission, lattice-enabled transmutation, fusion, or mutual annihilation) is so insanely high.

A workable hot fusion reactor of the kind Lockheed-Martin is working on will make solar panels, RTG's, LENR's, and even fission reactors look like toys at outputs levels near 100MWe.  In another 10 years or so, the best scientific minds in the world will still be fiddling with solar panels while LENR's the size of paint cans are powering vehicles that require several hundred hp or thereabouts.  Given the fact that radiation shielding is not required for LENR's, we may not even bother with fission reactors or fusion reactors until a colony is established.

Solar cells are useful for specific applications, but still a technological dead end if continuous high power output and energy density is a hard requirement, as would be the case for any successful Mars exploration or colonization effort.

It would be interesting to combine LENR's with a contra rotating co-axial rotor system and add aeromagnetic and or x-ray equipment into a larger drone that could be used for mapping, storm detection, mineral prospecting, search and rescue, and that would have a much greater range and load capabilities. Having large deposits mapped might help construction efforts among other things.

#24 Re: Life support systems » Lift off and touch down » 2016-10-21 14:14:09

kbd512 wrote:


SAFE-400 can transition from startup to maximum output in less than one hour and numerous startup/shutdown cycles have been demonstrated.  Within minutes of shutdown, radiation and heat drop to a few percent or less of the levels associated with normal operations.  Within approximately one hour of shutdown and most certainly after several hours, it's not biologically harmful or "safe" (there's that fabulous fictional word again) for humans to work on the reactor for an hour or two (put their hands on or otherwise handle something directly connected to the core).  Nuclear power plant personnel routinely do this here on Earth when they remove fuel rods from the core of a reactor.

Many nuclear power plant personnel have died from falls in cooling towers and reactor buildings or have been electrocuted by high voltage equipment, but the number of people who have died from handling fuel can be counted on one hand since we've started using nuclear power (and the ones who died did ridiculously stupid things that they didn't know were stupid because experimentation with nuclear fuels was still in its infancy and "safety" precautions or prudent handling of nuclear materials, as I call it, didn't exist).  Short of doing something ridiculously stupid that the astronauts would've been told to never do ahead of time (like standing on top of the core or in the immediate vicinity when the reactor is operating).  And yes, if you do something that stupid the radiation from an operating reactor will kill you (typically within one hour if you were actually standing on top of the core, one day at most if you were within a several meters of the core).

Radiation output drops exponentially with distance from the core.  The ground provides substantial shielding for every part of the core except the top of the core that is connected to the heat engine and radiators.  We could bury the core several meters down so an astronaut would have to fall into the reactor pit to die from radiation.  That'd be pretty damn hard to do since the pit is only 18" in diameter, but there's just no real need to do that.  If you stay 100M away or more, there is no radiation output that is harmful to humans because there is virtually no radiation received.  I personally think a compromise of building up a small berm around the reactor is sufficient.  If the reactor is one meter below the surface, you have to get a lot closer than 100M to get fried.  If the reactor is two meters below the surface, you have to stand in the hole to get fried.


I would be more worried about GCRadiation falling onto the surface of Mars and the radiation already on the surface in the rocks etc than a reactor because there is no guess about where it is or how to deal with it, the variables are already established.

#25 Re: Life support systems » Lift off and touch down » 2016-10-21 10:45:55

louis wrote:

Thanks for the clarification. I too favour using narrow canyons to develop pressurised earth-like environments, however I don't think they would be an early colony feature as their construction would take a lot of planning and effort.  Maybe after 10-20 years of colonisation we might be looking into that sort of thing.

Volcanism and subsurface cracks, caves where water might be found forming underground aquifers, geothermal heat, methane, protection from storms, possibility of finding remains of life, wind harvesting, maybe even ice fog utilization, these are some of possibilities of the Tharsis region but is it even possible to land in this area and what locations do you find compelling?

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