A human landscape...

louis · 2017-06-17 18:30:22

Riding my bike across a pleasant green open space on the outskirts of London, I began wondering how we might re-create that on Mars.
My fear is if we don't create those sorts of landscapes on Mars at an early stage we won't attract settlers in numbers.

So here are my thoughts...

1. We need large contiguous spaces where people can bike and trek and generally enjoy themselves.

2. The aim should be to create a space whiich feels natural and open.

3. It should of course incorporate a wide flora - trees, shrubs, ferns, flowers, and grass. This would mean there is a soil to a depth of at least 5 metres. The fauna may be more restricted but should include bees, beetles, birds, butterflies and deer. There should of course be water features - streams, ponds and lakes.

4. We can't just create one huge space. It needs to be broken up for reasons of safety and construction.

5. I am thinking of inter-connected domes or pillared spaces that could run for miles (no theoretical limit).

6. How high should the roof of this space be? I am thinking at least 50 metres but preferably 100 metres.

7. How do we support the roof? No doubt with pillars. These can be disguised as tall trees, in the same way many mobile phone masts are disguised as trees.

8. We need to replicate the experience of the sky above us. In Las Vegas they already do this with electronic screens of some sort. That is an option. I would favour a blue gas with white "clouds" of maybe CO2 being inserted into the translucent roof space.

9. When you pass from one pressurised environment to another, you will enter a tunnel, that appears quite natural and cave like. Sensors will open doors in front of you as you enter the air lock and so on before you pass to the other side. Each pressurised environment might encompass about a square mile.

10. There will be pressure differences within the defined spaces so as to create breeze effects.

11. There need to be differences in illumination to simulate natural conditions on Earth. Generally it should be brighter than normal Mars conditions...so that will require either light piping or artificial enhancement of the light.

I can imagine with this sort of environment covering maybe 20 square miles, someone could enjoy a really invigorating cycle ride of 30 miles in a changing landscape that feels v. natural. People who live in cities on Earth, don't really get much more than that, so I feel this would meet the minimum standard. You might have a city of 50,000 people on Mars surrounded by 5 of these Earth-analogue landscapes.

RobertDyck · 2017-06-17 19:40:54

Two points: 1) Mars doesn't have to be Earth. Let Mars be Mars. There are lots of open spaces on Mars. Take a walk or a drive in a Mars rover wearing your MCP spacesuit.

2) A terraformed Mars would start to look like what you describe. I ran a rough calculation using numbers provided by papers written on Terraforming. The text book "Terraforming: Engineering Planetary Environments" written by Martyn J. Fogg, which reference several published papers by other scientists. The paper by Dr. Chris McKay et al is one referenced paper. Using those figures, it should be possible to produce greenhouse gasses within one human lifetime. Then more decades to warm the planet. Once all or most of the CO2 is sublimated, that will produce an atmosphere thick enough for humans to walk outside without a pressure suit. It would still be a CO2 atmosphere, so would require an oxygen mask, but that's a lot safer than even an MCP spacesuit. Then grow plants to convert CO2 to oxygen. I posted another thread about using peat bogs to produce initial oxygen. So vast areas that look like a moor. The moor would initially require plastic sheet over it to concentrate O2 under the sheet. Living peat has more than one organism, at least sphagnum moss and cyanobacteria. The cyanobacteria does not require any O2, but sphagnum moss does. The plastic sheet would not be sealed, edges would allow O2 to escape, and for rain to get in. But it would hold O2 long enough for the moss. Once enough O2 is released, we can remove the plastic.

I could go into more detail: grinding rock, water circulation pumps, filters. Once enough O2 exists, plant black spruce in the bog. Grow to a boreal forest. Plant blueberry, raspberry, wild strawberry, saskatoon berry (aka Juneberry), cranberry, huckleberry, sarsaparilla (for root beer), lingonberry (aka cowberry, partridgeberry, mountain cranberry or foxberry), and cloudberry. But that's getting to advanced terraforming.

Is that what you're thinking about?

Last edited by RobertDyck (2017-06-22 13:36:25)

RobS · 2017-06-17 20:19:39

I like that answer, Robert.

I have always assumed that domes of transparent plastic laced with cables should be possible. The resulting structures resemble "upside down suspension bridges"; the cables are anchored deeply in the ground to counteract the upward pressure of all the air. Big cables connect to a network of smaller cables and finally a coarse net of small cables or wires, either embedded in the plastic or above the plastic. You might even want a double dome so that leakage is recaptured.

I suspect such domes could be built very wide. You could even use a series of cable arches to carry an extremely wide dome; possibly more than a kilometer or even two kilometers wide. The height of the dome could be anything you want, but a half circle would make the central dome height equal to half the width. A dome one kilometer wide therefore would soar upward 500 meters, which is higher than all but the tallest skyscrapers on Earth. That much air would itself provide some protection against cosmic rays.

The other thing that could be done with the domes is to include a water layer. Let us say the dome has a series of transparent "water bags" 3 meters tall suspended immediately below it. Their weight would counteract part of the upward pressure of the air. They would greatly reduce galactic cosmic rays that get through. You'd want the water to be sterile and crystal clear so they don't get scummy. You could also route all the extra heat trapped by the dome up into the water bags, so that the dome itself is warmer than the surface of the Earth--perhaps 50 Celsius--thereby radiating the solar heat trapped by the dome up into the Martian atmosphere. If there was some sort of fire in the dome, also, you'd have a built in system for putting it out.

Such an enclosed space would provide a semi-transparent view of the outside and of the Martian sky. Sunlight would pour in and agriculture would be possible in them. If the dome is a hundred or more meters overhead, one would have the sense of being in a very large open space. The ground underneath would be tilled and fertilized for plants to grow in it. And under the root layer would be a water table and under that, an ice table, to keep the air from leaking out downwards.

Such domes could be circular, but I'd build them long, like a Quonset hut. As the population increases, the engineers could try longer and wider ones. They might start with enclosures 100 meters wide and 50 meters long, but 5,000 square meters can only house and feed about 250 people, at 200 square meters per person. If you have a town of 100,000 people, your largest domes probably shouldn't hold more than 10,000 people, so that you have a lot of redundancy. Those enclosures would have 2 million square meters or 2 square kilometers. They could 1,000 meters wide and 2,000 meters long, or 500 meters wide and 4,000 meters long. Either way, they'd be quite spacious.

Note: I am not sure of the figure of 200 square meters per person, but you can feed one person in an area that large, and if you put the housing and work areas underneath the agriculture--either by putting the farms on the roof or the buildings underground--I think that's a good number to use for a Mars base. It might be that 100 square meters is enough. But as the population grows, you will want more and more plant diversity. You'll want tropical enclosures to grow citrus, temperate enclosures for apples and other plants that need some winter, desert enclosures for other things, etc. By routing more or less trapped solar heat from the enclosures, each can have a different climate. By raising curtains along the sides, the number of hours of daylight could be reduced to move an enclosure toward winter. In my novel I even envisioned "bioarchives," that a Mars settlement might have some natural environments for specific terrestrial ecologies so that it has access to a wide variety of plant species.

SpaceNut · 2017-06-17 20:42:39

Settlers, colonists are sure going to be dreamers of a future mars, they will be risk takers but for this to happen costs to get man there must drop to be able to have any more than the rich going. There must be incentive to want to go just like those wandering the Oregon trail....if you go to stay your trip and first cycles supplies are free but to get more you will need to work on this to do list of science, construction ect....

Antius · 2017-06-18 17:09:11

The pillar structure that you mention would be the most easily achievable from an engineering viewpoint. You could start by finding a depression such as an impact crater. Within the crater lay down a series of square steel lattice domes, supported by a vertical leg in each corner and with a sunlight tube some 10m tall extending upward from the middle. Cover the domes with rock and soil to a depth of 10m and provide gravity stabilized berms at the outer edges. You can do this by using a front end earth mover to simply push surrounding rock and regolith onto the lattic structure until its about 10m deep. Pressurize with air and then move in. You could paint the ceiling blue if you wanted to.

If sunlight tubes account for say 50% of the surface area of the steel lattice, then there would still be sufficient light for crop growth underneath. The steel supports at the corners of each dome could serve as lateral stabilizing supports for adobe buildings. In these, you would have accommodations, commerce and factory buildings as required. Solar panels could be placed on the surface between the skylights with cables passing through the regolith and rock layer into buildings directly beneath. If cabling is kept relatively short in this way, buildings can be wired for 24v DC without the need for transformer and inverter losses from the solar panels.

The sunlight pipes would have convex glass dome covers on the inside to resist internal pressure. At the top side, a thin glass cover would be in place to prevent dust accumulation within the pipe. The pipe itself would be coated in aluminium to allow light to pass down the tube. The inner skylight and dust cover would both absorb infrared light. This, and the thick layer of gravity stabilising rock and regolith would help keep heat in during the freezing Martian night.

If each steel lattice is say 50m high and 30m between its legs, then individual frames can be lifted in by crane and the legs braced together and to neighbouring lattices for stability. As the skylight is about as wide as the sunlight tube is tall, only those cosmic rays that enter the aperture at less than a 30 degree angle will make it through.

A lattice dome some 30m wide would cover some 900m2. To cover 1km2, some 1100 lattice domes would need to be stacked in square configuration. Habitats could be divided into cells by separating them with earth berms and having tunnels run through them, much as Louis suggested. This would protect residents against catastrophic depressurisation and fire.

Last edited by Antius (2017-06-18 17:47:07)

louis · 2017-06-18 18:37:12

Yes, I was thinking a crater (or series of craters) might make a good topographical starting point for such a project.

I am impressed by your technical suggestions... Feel free to suggest nuclear reactors to boost the light.

Although I am thinking on a rather large scale here, obviously one would start with much smaller spaces and gain experience about how to operate these sorts of Earth-analogue environments before you started creating the much larger environments.

Soil is a bit of an issue. On a rough calculation you might need 12.5 million tonnes of soil per square mile (going down to a depth of 5 metres). That would mean you would have to have a number of facilities capable of processing thousands of tonnes of regolith each day in order to generate that amount of fertile soil. But again, you don't have to leap to that immediately, you can build up gradually.

Antius wrote:

The pillar structure that you mention would be the most easily achievable from an engineering viewpoint. You could start by finding a depression such as an impact crater. Within the crater lay down a series of square steel lattice domes, supported by a vertical leg in each corner and with a sunlight tube some 10m tall extending upward from the middle. Cover the domes with rock and soil to a depth of 10m and provide gravity stabilized berms at the outer edges. You can do this by using a front end earth mover to simply push surrounding rock and regolith onto the lattic structure until its about 10m deep. Pressurize with air and then move in. You could paint the ceiling blue if you wanted to.
If sunlight tubes account for say 50% of the surface area of the steel lattice, then there would still be sufficient light for crop growth underneath. The steel supports at the corners of each dome could serve as lateral stabilizing supports for adobe buildings. In these, you would have accommodations, commerce and factory buildings as required. Solar panels could be placed on the surface between the skylights with cables passing through the regolith and rock layer into buildings directly beneath. If cabling is kept relatively short in this way, buildings can be wired for 24v DC without the need for transformer and inverter losses from the solar panels.
The sunlight pipes would have convex glass dome covers on the inside to resist internal pressure. At the top side, a thin glass cover would be in place to prevent dust accumulation within the pipe. The pipe itself would be coated in aluminium to allow light to pass down the tube. The inner skylight and dust cover would both absorb infrared light. This, and the thick layer of gravity stabilising rock and regolith would help keep heat in during the freezing Martian night.
If each steel lattice is say 50m high and 30m between its legs, then individual frames can be lifted in by crane and the legs braced together and to neighbouring lattices for stability. As the skylight is about as wide as the sunlight tube is tall, only those cosmic rays that enter the aperture at less than a 30 degree angle will make it through.
A lattice dome some 30m wide would cover some 900m2. To cover 1km2, some 1100 lattice domes would need to be stacked in square configuration. Habitats could be divided into cells by separating them with earth berms and having tunnels run through them, much as Louis suggested. This would protect residents against catastrophic depressurisation and fire.

SpaceNut · 2017-06-19 20:03:40

What better way to make mars like earth than to Beer in space: Budweiser wants to set up a brewery on Mars, apparently

Age 2 years after brewing in transport after adding that zesty mars carbonation.....

RobertDyck · 2017-06-20 00:40:32

louis wrote:

Soil is a bit of an issue.

That was the starting point of my peat bog idea. A book by Robert A. Heinlein called "Farmer in the Sky" was about a terraformed Ganymede. In that book a farmer arrives, but when he arrives at the land he's assigned it's solid bedrock. A neighbour greets him and tells him the first crop they have to grow is soil. My idea is based on the process described, but with refinements.

Grind rock to rock flour, to a depth of 2 metres. I pick that depth because wheat requires that much soil. Cut a pit periodically into the bedrock before laying the rock flour back. Layer a slow sand filter into the pit: course rocks on the bottom, then gravel, then course sand, then fine sand on top. With a stainless steel grid in the very bottom beneath the course rocks, with spacing just small enough that the rocks can't get through. This will let water seep through, but filter out contaminants. For this purpose, it will prevent rock flour from coming through. A water pipe or large hose would uptake water from the bottom of that pit, pump it onto the surface. A pole would support a solar panel to provide power, with a battery behind the solar panel. Water pump would be an immersion pump, underground so it doesn't experience temperature fluctuations with weather. Don't want the pump to freeze. You could put water quality sensors to measure temperature, pH, salinity, calcium, phosphate, ammonia, iron (bivalent and total), general hardness, and carbonate hardness. The last is a total of calcium + magnesium, by subtracting calcium you can determine magnesium. This data would be logged by a microcontroller. It would also have a WiFi repeater node. The pump could be controlled and the data downloaded remotely via WiFi.

The point is sphagnum moss produces acid to dissolve rock. This releases potassium, phosphate, and micronutrients for the moss and other plants. It also breaks down rock to form clay. High quality soil is a mixture of clay, loess, and peat moss. Loess is rock flour produced naturally by glaciers, this would have rock flour produced artificially. With cyanobacteria producing ammonia, and other bacteria converting ammonia into nitrite and then nitrate, you have rich soil.

I tried an aquarium experiment of this. With a plastic under-gravel water filter on the bottom, uncoloured aquarium gravel on that, then commercial rock flour. Turns out that rock flour is glacial, from the Rocky mountains. And I got a sample of live peat from a company that harvests peat moss for sale to garden centres. The live peat is the "top moss". And I used steam distilled water purchased from a grocery store. Used an aquarium water pump to circulate water. And tested water quality with aquarium water test kits. It worked at first, then I guess it worked too well. Water was initially acidic, but quickly became strongly alkali. Once it did that, the peat moss died. With no more live sphagnum moss to produce acid, it couldn't recover. The water hardness was extreme! General hardness is measured in mg/L. For tap water, mildly hard water is 17.1 to 60 mg/L, moderately hard is 60-120 mg/L, hard is 120-180, and very hard is anything above 180. The moss died when the water hit 380 mg/L! What do you call that?

Ok, so acid from sphagnum moss dissolved calcium and magnesium out of the rock. That's how you convert it to clay. But the calcium and magnesium were extreme! We need something to remove them. Perhaps lime softening to remove it. Once sufficient ground rock (rock flour) has been converted to clay, the peat bog will be very acid. Too acid for crops. To neutralize the acid, add the lime (calcium and magnesium) back in.

I suggest a two step process. First partially neutralize acid, so there's still sufficient acid for peat moss to grow, but acid weak enough to allow black spruce trees and berries to grow as well. A boreal forest growing in the peat bog. Trees will add more organic matter as well as producing oxygen. Once the soil has been converted sufficiently, you could burn the forest to form wood ash, as well as remaining lime (calcium/magnesium) from the lime water filter. This would reduce acid to the level appropriate for food crops such as wheat.

I wonder if the process could be sped up further by genetically modifying a tree to require less oxygen. If it can grow in atmosphere with a lot less oxygen, then you can plant the forest much sooner. Trees will release a lot more oxygen than sphagnum moss and cyanobacteria.

So there's a process to produce soil over vast areas.

Last edited by RobertDyck (2017-06-22 13:35:43)

RobertDyck · 2017-06-20 00:48:56

SpaceNut wrote:

Beer in space: Budweiser wants to set up a brewery on Mars, apparently
click for larger version of info-graphic

I don't see most of the points in the points they mention. It's just marketing. Zero-G isn't an issue on Mars. You won't drink outside without a spacesuit. A settlement would be built where there's water, I suggested Elysium Planetia where ESA says there's more water than all the Great Lakes combined. Salt would be filtered out before making beer. You wouldn't drink outside when it's -100°F. You could grow hops in a greenhouse with mirrors to double illumination, so they would have equivalent of direct sunlight.

Most importantly, I prefer stout. "Guinness is good for you." Budweiser isn't stout. Or is that what they want to campaign against?

louis · 2017-06-20 02:56:04

Some excellent ideas there Robert...you've obviously really taken on board the size issue. I guess the good thing about your approach is that you can experiment small scale and then work up gradually to large scale spaces. Would be marvellous to see this done on Mars.

RobertDyck wrote:

louis wrote:
Soil is a bit of an issue.
That was the starting point of my peat bog idea. A book by Robert A. Heinlein called "Farmer in the Sky" was about a terraformed Ganymede. In that book a farmer arrives, but when he arrives at the land he's assigned it's solid bedrock. A neighbour greets him and tells him the first crop they have to grow is soil. My idea is based on the process described, but with refinements.
Grind rock to rock flour, to a depth of 2 metres. I pick that depth because wheat requires that much soil. Cut a pit periodically into the bedrock before laying the rock flour back. Layer a slow sand filter into the pit: course rocks on the bottom, then gravel, then course sand, then fine sand on top. With a stainless steel grid in the very bottom beneath the course rocks, with spacing just small enough that the rocks can't get through. This will let water seep through, but filter out contaminants. For this purpose, it will prevent rock flour from coming through. A water pipe or large hose would uptake water from the bottom of that pit, pump it onto the surface. A pole would support a solar panel to provide power, with a battery behind the solar panel. Water pump would be an immersion pump, underground so it doesn't experience temperature fluctuations with weather. Don't want the pump to freeze. You could put water quality sensors to measure temperature, pH, salinity, calcium, phosphate, ammonia, iron, and carbonate hardness. The last is a total of calcium + magnesium, by subtracting calcium you can determine magnesium. This data would be logged by a microcontroller. It would also have a WiFi repeater node. The pump could be controlled and the data downloaded remotely via WiFi.
The point is sphagnum moss produces acid to dissolve rock. This releases potassium, phosphate, and micronutrients for the moss and other plants. It also breaks down rock to form clay. High quality soil is a mixture of clay, loess, and peat moss. Loess is rock flour produced naturally by a glaciers, this would have rock flour produced artificially. With cyanobacteria producing ammonia, and other bacteria converting ammonia into nitrite and then nitrate, you have rick soil.
I tried an aquarium experiment of this. With a plastic under-gravel water filter on the bottom, uncoloured aquarium gravel on that, then commercial rock flour. Turns out that rock flour is glacial, from the Rocky mountains. And I got a sample of live peat from a company that harvests peat moss for sale to garden centres. The life peat is the "top moss". And I used steam distilled water purchased from a grocery store. Used an aquarium water pump to circulate water. And tested water quality with aquarium water test kits. It worked at first, then I guess it worked too well. Water was initially acidic, but quickly became strongly alkali. Once it did that, the peat moss died. With no more live sphagnum moss to produce acid, it couldn't recover. The water hardness was extreme! General hardness is measured in mg/L. For tap water, mildly hard water is 17.1 to 60 mg/L, moderately hard is 60-120 mg/L, hard is 120-180, and very hard is anything above 180. The moss died when the water hit 380 mg/L! What do you call that?
Ok, so acid from sphagnum moss dissolved calcium and magnesium out of the rock. That's how you convert it to clay. But the calcium and magnesium were extreme! We need something to remove them. Perhaps lime softening to remove it. Once sufficient ground rock (rock flour) has been converted to clay, the peat bog will be very acid. Too acid for crops. To neutralize the acid, add the lime (calcium and magnesium) back in.
I suggest a two step process. First partially neutralize acid, so there's still sufficient acid for peat moss to grow, but acid is weak enough to allow black spruce trees and berries to grow as well. A boreal forest growing in the peat bog. Trees will add more organic matter as well as producing oxygen. Once the soil has been converted sufficiently, you could burn the forest to form wood ash, as well as remaining lime (calcium/magnesium) from the lime water filter. This would reduce acid to the level appropriate for food crops such as wheat.
I wonder if the process could be sped up further by genetically modifying a tree to require less oxygen. If it can grow in atmosphere with a lot less oxygen, then you can plant the forest much sooner. Trees will release a lot more oxygen than sphagnum moss and cyanobacteria.
So there's a process to produce soil over vast areas.

louis · 2017-06-20 02:58:26

Great find...this is really a rather nice straw in the wind...I have always thought that one Mars colonisation become a reality a lot of companies would want to get in on the act because it offers marvellous free publicity and there is inherent value in being "first" in whatever field. This seems to confirm that. Whether or not they are serious, it is great because it will gradually make people think that Mars settlement is a realistic prospect and not some distant science fiction event.

SpaceNut wrote:

What better way to make mars like earth than to Beer in space: Budweiser wants to set up a brewery on Mars, apparently
Age 2 years after brewing in transport after adding that zesty mars carbonation.....
https://icdn2.digitaltrends.com/image/b … 12x570.jpg

Antius · 2017-06-22 10:35:22

Interesting ideas on soil creation. I think a big hurdle on Mars is going to be the 0.2-1% by weight perchlorate compounds in the regolith. That stuff is basically weed killer and is toxic to all animal life. There may be other salts that impair plant growth. Luckily all of these toxins are water soluble and can be removed by dissolving and then freezing. As the perchlorate is a strong oxidising agent it can either be broken down to yield oxygen or reacted with any organics we can find on Mars as a fuel.

Also, we discussed earlier the possibility of covering simple steel frames with regolith in order to create pressurised habitable spaces within depressions like craters. Here is a link to a shape that may be useful.

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

As the base has a square cross-section, these units could be stacked together to form continuous spaces. The central dome could have a large sunlight pipe in the middle protruding through the regolith to the surface. If the sunlight pipes have cross-sectional area equal to 50% of total enclosed area, and the area is located at the equator, then the average solar intensity within the habitat will be 750kWh/year. That's about the insolation that Scotland or Northern Canada receive. Enough for crop growth and abundant plant growth if temperatures are kept warm.

Last edited by Antius (2017-06-22 10:37:42)

SpaceNut · 2017-06-22 20:32:39

Interesting that we are talking about a non clear dome needing a light pipe...

Antius · 2017-06-23 07:19:45

This may be a key enabling technology:

https://www.theverge.com/2017/4/27/1543 … n-missions

If Mars soil behaves in the same way as the simulant, we wont need steel frames to manufacture these habitats. Just hydraulic rams and steel moulds, forming components from rammed regolith. These components can be manufactured to slide together or be bolted together.

This might provide a use for Louis's solar power, as regolith will be too cold to collect at night and the steel within the moulds too brittle at low temperatures.

Last edited by Antius (2017-06-23 07:22:47)

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A human landscape...

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