We need a brainstorming session! - Bat around a few ideas.

Lil_vader · 2001-09-06 13:14:02

I have lots of ideas for a permanent Martian colony, and I'd like to hear if anyone else has any.

John Creighton · 2001-09-06 18:18:17

To be brief I'll say planing and engineering. For more details you can look at my mars page.

Lil_vader · 2001-09-07 13:08:39

I noticed that the design you have assumes a one-layer, transperant dome. But what if we used a multi-layered, opaque dome instead? That way, we could use self-sealing pockets to catch projectiles and prevent punctures. If we used several layers of bulletproof fabric with packets of a tar-like substance in between, and with the innermost layer able to maintain the atmosphere by itself, then repairs could be made by simply replacing the damaged packet and patching the punctured fabric. The people wouldn't have to worry about dying from a tiny meteorite hole.

With the decreased sunlight available on Mars, it might be more efficient to use artificial lighting indoors, anyway. There could be a solar array outside of the building, collecting power for the colony. It would have to be larger than what a simular colony would need on Earth, but it would last a long time.

John Creighton · 2001-09-07 14:31:46

Hmmm, It?s hard to consider how advances in material science will help to make domes safer. Was the tar like material to slow down and stop the meteorites or to help seel the hole after a puncture? An interesting idea to seel the structure after a puncture might be some kind of smart fabric. Imagine where the puncture occurs there is fibbers that run around the puncture. Imagine the fabric somehow knows the rip occurred inside this ring of fibres. Imagine the material then contracts those fibbers, sealing off the puncture. Now Imagine the material can slowly repair the puncture, consequently placing less and less stress on the contracted fibbers.

Lil_vader · 2001-09-08 10:08:07

Actually, the tar would both stop the meteorite AND seal the hole. It's simular to the self-sealing weatherproofing used on cellphone towers, so we wouldn't have to wait for the technology.

Alexander Sheppard · 2001-09-23 15:06:43

Meteorites don't pose too much of a threat to Martian domes, perhaps enough that we would want to take some minor precautions, but nothing more. Even if a small one, which is the only real threat, punctured a colony-sized dome, it would take years for the air to leak out, so there is no threat. Large impacts are extremely improbable and impossible to plan for anyway [since everything would blow up upon impact].

That raises another question about domes. How do you deal with fire? A big fire would be extremely dangerous ; not only could it melt the dome apart, but it could fill a sealed dome with noxious gas, killing all those not already with pressure suits on.

kelly · 2001-09-24 15:20:22

Aha, someone finally asks something that has been bugging me for awhile...FIRE. Not only in the domes, but what about on the flight vehicles? Halon may be great for putting out fires, but it's really bad for the lungs. And what to do with the now poisonous air once the fire is out. CO2 could be used, then scrubbed out of the air, or absorbed with Lithium Hydroxide. Most chemicals used to make material fire retardent have major outgassing (fumes) problems also.
Being on submarines for 21 years now I can assure you the problems of atmosphere control in general, and fire in particular, are pretty serious and not all the questions have been answered yet.
Perhaps a good topic for a new Task Force to work on; Atmosphere control and Damage Control for a manned mission.

Adrian · 2001-09-24 16:46:04

It's definitely an interesting question. Are there any kind of inert, non-toxic gases that could be used for suppressing fires? Or perhaps some kind of computer controlled foam jet could be used, placed at the top of each dome?

It might be useful to have a look at the fire suppression guidelines for the Space Shuttle, Mir and the ISS - they clearly must have had the same thoughts as us about these problems, especially in Mir's case.

kelly · 2001-09-27 10:53:40

Thats very true except these stations have near instant access to atmosphere replenishment. A shuttle can set up an emergency landing, Mir and the ISS can be resupplied via ground launch.
Whatever is used on the Mars Mission has to be self contained and recyclable (But thats stating the obvious...sorry).
I guess it's research time.

Lil_vader · 2001-09-27 12:14:13

For the colony itself, there are several measures that can be taken to prevent and stop fires.

1. Wherever possible, use fiber optics instead of electrical wire.
2. Wrap all electrical wire in several layers of Teflon, which has an EXTREMELY high melting point.
3. Compartmentalize whenever possible, so that if fire somhow breaks out it won't spread. It will also take less to put out the fire this way.
4. Use Teflon in the dome layers. It has a high melting point, is flexible down to almost absolute zero, and is not chemically reactive.
5. In the gardens and arboretums, have several sensors around the place rigged to the water table. If a fire is detected, then the water table can be raised to a few feet above ground, smothering the flames without hurting anyone.

Fire needs oxygen, but it also needs fuel. By limiting the available combustables, it is possible to drastically reduce the chances of a fire breaking out.

Adrian · 2001-09-28 13:18:15

I agree with all your points, with the exception of number 5; let's face it, water will always be a precious resource on Mars and even if you had a lot of it you wouldn't want to be ruining your plants and other equipment by raising the water table. Some kind of temperature-sensitive water jet system would be fine, I should think.

Lil_vader · 2001-10-03 14:06:00

I was thinking that raising the water table would keep the fire from smoldering, thus helping to preserve oxygen. Forest fires have been known to smolder underground for days, only to flare up again at random. I know that water will be precious, that's why it would only make sense to have large stores of it. If done right, the water table could be raised to a few feet above ground, then lowered again without ruining the water for other uses. What's more, most plants are capaple of surviving short floods without damage, some even grow better after such a flood. If done right, the effects on the plants would be the same as a heavy rain.
As for equipment, if the colony is compartmentalized, then the fire and the flood would both be contained in a small area. There should be no need for something that would be destroyed by water to be in the arboretum.

It's nice to have people to talk ideas out with. Thank you.

Lil_vader · 2002-01-05 23:01:48

Hey! We're back!

Found an article about another way to produce breathable oxygen that might work for flight vehicles:

http://ares.ame.arizona.edu/stack/SOE_Stack_intro.html

Phobos · 2002-01-06 00:20:28

Even though I can't really defend myself with any facts, I get the feeling a transparent dome would be better from a psychological standpoint than an opaque one, especially if the dome is meant to cover a large area such as enough to cover a small town.

Lil_vader · 2002-01-06 14:13:30

Mars is far enough away from the sun that the light through a transparent dome would probably be more depressing than benificial. Full-spectrum lights designed in a way that would mimic the sun would probably work better, and from a structural viewpoint an opaque dome is much easier to build and maintain.

But I'm glad someone is thinking of the psychological aspects of the colony.

P.S.: One large dome is a rather inefficient design. Maybe several interconnected domes? Or maybe longhouse-style instead of domes?

Josh Cryer · 2002-01-06 14:57:37

One large dome is a rather inefficient design.

Probably, if it was like a couple of miles across or something. But one the size of a football or soccer field that was supported by air would be very efficient.

Teflon isn't what you want to build it out of, however. You want something like Kevlar, or UHMWPE. Better yet, a UHMWPE (ultra-high molecular weight polyethylene), carbon fiber composite. The thing would be nearly invincible! And rather easy to make since carbon and hydrogen are common on Mars. (Kevlar needs nitrogen, so it may be harder to create than a UHMWPE composite.)

Links to (easy to read) notes about polymers:

polyethylene
polyacrylonitrile (carbon fiber)
kevlar

Found an article about another way to produce breathable oxygen that might work for flight vehicles.

The unit currently under development will produce an infinite amount of oxygen, given the electrical power, time, and oxygen bearing gas.

Not only could this be useful for flight vehicles, this could be very useful for both life support on Mars, and ultimately terraformation. I suspect it's more efficient than plants from a time / energy perspective.

Lil_vader · 2002-01-07 22:15:33

When I said "one large dome", I was refering to the comment
"especially if the dome is meant to cover a large area such as enough to cover a small town." That would be a couple of miles across. I was considering a dome the size of a football field to be a "smaller dome", and several of them interconnected would probably be perfect

Josh Cryer · 2002-01-08 00:20:04

Yeah, domes the size of a football stadium would be perfect, and since they're interconnected one could refer to the domed structure as one domed town or city. And it really wouldn't take much to equal a small town. In fact, one dome the size of a football stadium could be considered a town, as it would probably have a population of hundreds, perhaps even thousands.

Shaun Barrett · 2002-01-24 22:19:33

This is all great fun to think about but I can't get the nagging feeling out of my mind that it might be a little premature. I know, I know ..... if I can't play nicely with the other kids and only want to spoil the game, then I should go to my room!!
O.K., I'll be good! ... One question I did think of relates to radiation and U.V. light. I imagine the dome material, whether transparent or opaque, can be made impervious to U.V. or even engineered to allow through a modicum of U.V. if necessary, for plants (do they need it?) or just so you could still get a nice tan by the pool! Incidentally, for what it's worth, I tend to side with those in favour of transparent domes for psychological reasons. In fact I would even suggest making the anchoring structure around the perimeter as inconspicuous as possible to enhance the "open-air" feel of the place.
But what about particle radiation? How much air, presumably at pressures of 1 bar (is that what we're aiming for?), would be needed to block most of the damaging stuff from space? My point is this: If thicknesses of tens of metres of dense air were to make any difference to radiation flux, and if the "tallest" dome is hemispherical, then the bigger the diameter of the dome the better. If lots of air between you and the dome is a good idea, then make the dome a hemisphere with a kilometre radius; thus giving yourself a thousand metres of lovely gaseous protection above your head! (At least in the middle of the dome.) And, as a bonus, you could build high-rise buildings to conserve space inside the dome for recreational purposes, and get great views out over the rugged Martian topography.
Now watch while an expert rolls up and blithely informs me that you need way more than a kilometre of air at 1 bar to make any difference to radiation from space!! And after all that hard thinking I did, too!
Well ... did I play nicely? And does anyone wanna take the ball and run with it?!

RobS · 2002-01-25 00:10:11

Actually, I think Shaun's idea of air shielding is clever. The Earth's atmosphere provides 10 tonnes per square meter of air over our heads, and half of that is in the lower 5 kilometers or so of the atmosphere. Air has a mass of 1.5 kilograms per cubic meter when compressed at 1 atmosphere of pressure. So 100 meters of air would provide 150 kilograms of shielding per square meter of surface. The entire Martian atmosphere provides about half of that. The Hab's radiation shelter on the flight out to Mars provides 350 kg per square meter.

But the simplest, most practical shielding is to build the living and work areas with several tonnes of mass overhead, by loading their roofs with dirt. People are outside only a few hours a day, usually, so their radiation exposure while outside would not be serious. They could always minimize it during solar flares.

I, too, favor transparent domes, though in a posting on another topic I suggested the domes might need to be covered with an insulating shroud at night to help hold in heat. You would want to let in some ultraviolet, if possible, because bees need it to navigate. This was a big problem with Biosphere 2 down in Arizona, because glass does not admit ultraviolet. Bees starved to death and went extinct in Biosphere 2 because they could not navigate from hive to flower and back; they could not see the sun in ultraviolet. Setting up a few uv lights didn't help, either.

One could easily bury a dome's edge so that one could walk right up to it and look out. Perhaps the opposite side of the dome would have housing with big windows, so people could look out over wheat fields to a barren Marscape beyond. The only danger is the ease one makes very serious vandalism.

-- RobS

CaptainRich · 2002-02-01 12:53:44

I have been doing some redesigns of my Roman style vault renderings. The new renderings are at

http://dolphin-watch.com/render.html

I'm currently working on an interior landscape for the central courtyard as well as several animations.

Hope you like them.

Captain Rich

Phobos · 2002-02-01 19:44:26

I'm currently working on an interior landscape for the central courtyard as well as several animations.
Hope you like them.

Nice renderings. The only thing I wonder about is how you're going to keep the structure completely buried in a shroud of soil above ground without retaining walls. Having done a lot of work is this area, it seems to me that you would need to build retaining walls 2.5 meters taller than the structure itself and then fill in the area between those walls with soil until your habitable structure is beneath the required amount of soil. Another thing that I've often wondered about is where the water will come from to make all of that grout/mortar/concrete. It seems that for a project like this to be built there would need to be an established infrastructure on Mars capable of producing large quantities of water just for the production of the building materials.

RobS · 2002-02-01 21:09:08

What cool images! One thing I wonder about is; isn't it a lot of work to have astronauts laying bricks in space suits? I'd think if duricrete can be made--apparently a lot of Martian materials will cement together if they are wetted--then if water can be extracted from the ground easily enough, it'd be easier to pour duricrete structures in molds, then bury them with dirt after they've hardened.

-- RobS

CaptainRich · 2002-02-05 12:56:39

Phobos and Rob S. have mention a couple of issues that I've thought about.

1) Water for the mortar. Would it be possible to erect a temporary inflatable structure around small sections of the construction site? This could be used to recover the water as the mortar sets as well as being able to warm the site to make it set faster. Once the mortar has setup you take it down and move it to the next section. These inflatables would be at very low pressures and would NOT supply an environment for the construction crews.

As far as the main water supply, I think the site selection will be in a location where an aquifer has been found to supply a larger base.

2) Making the whole base out of poured concrete. This sounds possible, except the need for mold material, and the huge supply of concrete that will be needed. We have this capability on Earth and yet we still use brick for a lot of construction. Maybe someone else has good reasons, pro or con, about this subject.

3) Retaining walls for the berm. Ok, here is where I'm just winging it! I was just trying to render the Underhill concept. I'm fairly certain that the high retaining walls where the airlocks are placed is WRONG. If you can tell me a better way to design this I'll try to replace the flat walls that I'm currently using.

The slope of the main berm might be wrong as well, but I don't think it will need a retaining wall to hold it in place. The berm will be just regolith dumped over the vaults. The lower gravity of Mars might allow the steeper slope of the berm.

4) Laying bricks in a space suit. I think most of the actual bricklaying will have to be done by robots. This will be such a labor intensive job that I can't believe we'll devote that much marsnaut time to such a task.

5) The trench habitat in Red Mars. I have been thinking about how to render this next! Why wouldn't you just dome over the whole trench? In Red Mars they glassed it in from the lip of the south wall to the BASE of the north wall. Wouldn't it make better sense to just glass over the whole thing? If you erect the superstructure for the "dome" before you do any digging then you could use it as a support structure for an automated dragline to do most of the excavation.

By the way if anyone has any ideas of how to improve the designs I've done than please let me know!

Thanks.

Phobos · 2002-02-07 22:31:56

1) Water for the mortar. Would it be possible to erect a temporary inflatable structure around small sections of the construction site? This could be used to recover the water as the mortar sets as well as being able to warm the site to make it set faster. Once the mortar has setup you take it down and move it to the next section. These inflatables would be at very low pressures and would NOT supply an environment for the construction crews.

You bring up a good point about temperature. Generally cementious type materials lose the ability to form good bonds
if the temperature goes below 40 F. As far as heating goes, you might want to use enclosures with electric heating elements to maintain the temperature somewhere between 60 and 80 F if you use the standard Portland type cement materials. You can also add "antifreeze" admixtures to the concrete/mortar to insure that it sets up at a lower temperature. Good point about moisture loss also. You don't want to lose water very quickly or the strength of the concrete goes down. Your probably right in that such a structure might have to be built and allowed to cure under a properly heated/pressurized "tent." I get the feeling Martian construction will chuck many of the standards and practices we use here on Earth and develop its own unique building methods.

3) The slope of the main berm might be wrong as well, but I don't think it will need a retaining wall to hold it in place. The berm will be just regolith dumped over the vaults. The lower gravity of Mars might allow the steeper slope of the berm.

Taking Martian gravity into consideration, I'm not sure if an outer retaining wall would be absolutely necessary, but you'd probably need a lot more soil to make up for the tendency of material to just slump out horizontally when it's piled up. It might be ideal to build something like this inside a huge crater because then you'd have natural retaining walls enclosing the structure. Or you could just dig a massive pit in the ground and then fill it back in once you build the structure considering your going to have to dig one anyway to get the covering material.

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#1 2001-09-06 13:14:02

Re: We need a brainstorming session! - Bat around a few ideas.

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Re: We need a brainstorming session! - Bat around a few ideas.

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Re: We need a brainstorming session! - Bat around a few ideas.

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Re: We need a brainstorming session! - Bat around a few ideas.

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Re: We need a brainstorming session! - Bat around a few ideas.

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Re: We need a brainstorming session! - Bat around a few ideas.

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Re: We need a brainstorming session! - Bat around a few ideas.

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Re: We need a brainstorming session! - Bat around a few ideas.

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