Quote from: uhuznaa on 10/12/2016 12:35 pmQuote from: lamontagne on 10/12/2016 11:34 amQuote from: TheTraveller on 10/12/2016 10:39 amIce Dome Construction for Large Scale Habitats on Atmosphere Less Bodiesas attached with examplesMethod only works at high altitudes on Mars.You need to insulate the dome if you want to have above 0 temperatures inside.I believe there is a limit to the altitude the ITS can land because it requires aerodynamic braking. Do the two match up?On the other hand, the mechanical characteristics of ice can be improved significantly by additives, to create a material similar to fiber reinforce plastics, Pykrete. The same dome could be build from the outside, rather than from the inside, using hoses and a supply of fibrous material. Wouldn't be transparent, though, although perhaps translucent, depending on the fiber used.What is the cheapest fiber than can be obtained/produced on Mars?What is the heat balance of a Martian building? Houses are not very energy intensive, but the heat load from an efficient plantation may be quite high, for example. A greenhouse (or more aptly a grow house) in ice might be a significative challenge, at the lighting levels can reach hundreds of watts per m2. Intensive grow houses on Earth require active cooling. So you may have a cheap building, but if it requires constant active cooling and a radiative cooling system, it may not be the safest place to live.Thermal management will just be one of the problems you will have to solve. But if you're sitting in the midst of a glacier stretching for tens of miles and half a mile thick, some water coolant loops that dump the heat somewhere else (or heat your insulated fish pool) shouldn't be that hard. It's basically only slightly used energy, you will find a use for it...People who lives in meltable houses need to worry about heat ;-)In a more serious vein (of underground water) coolant loops and piping can get expensive. You can simply dump melted water into the atmosphere, where it will sublimate nicely enough. Should just need a fairly small pool. but you can't cool your ice house with liquid water, since it is necessarily hotter than the ice. You would need to use salt water (brine), or a glycol. then you will be using salt and recycling it, which can get intensive on a large scale.Or you can use large arrays of piping, but large arrays of piping are extremely expensive, just talk to geothermal heat pump vendors...
Quote from: lamontagne on 10/12/2016 11:34 amQuote from: TheTraveller on 10/12/2016 10:39 amIce Dome Construction for Large Scale Habitats on Atmosphere Less Bodiesas attached with examplesMethod only works at high altitudes on Mars.You need to insulate the dome if you want to have above 0 temperatures inside.I believe there is a limit to the altitude the ITS can land because it requires aerodynamic braking. Do the two match up?On the other hand, the mechanical characteristics of ice can be improved significantly by additives, to create a material similar to fiber reinforce plastics, Pykrete. The same dome could be build from the outside, rather than from the inside, using hoses and a supply of fibrous material. Wouldn't be transparent, though, although perhaps translucent, depending on the fiber used.What is the cheapest fiber than can be obtained/produced on Mars?What is the heat balance of a Martian building? Houses are not very energy intensive, but the heat load from an efficient plantation may be quite high, for example. A greenhouse (or more aptly a grow house) in ice might be a significative challenge, at the lighting levels can reach hundreds of watts per m2. Intensive grow houses on Earth require active cooling. So you may have a cheap building, but if it requires constant active cooling and a radiative cooling system, it may not be the safest place to live.Thermal management will just be one of the problems you will have to solve. But if you're sitting in the midst of a glacier stretching for tens of miles and half a mile thick, some water coolant loops that dump the heat somewhere else (or heat your insulated fish pool) shouldn't be that hard. It's basically only slightly used energy, you will find a use for it...
Quote from: TheTraveller on 10/12/2016 10:39 amIce Dome Construction for Large Scale Habitats on Atmosphere Less Bodiesas attached with examplesMethod only works at high altitudes on Mars.You need to insulate the dome if you want to have above 0 temperatures inside.I believe there is a limit to the altitude the ITS can land because it requires aerodynamic braking. Do the two match up?On the other hand, the mechanical characteristics of ice can be improved significantly by additives, to create a material similar to fiber reinforce plastics, Pykrete. The same dome could be build from the outside, rather than from the inside, using hoses and a supply of fibrous material. Wouldn't be transparent, though, although perhaps translucent, depending on the fiber used.What is the cheapest fiber than can be obtained/produced on Mars?What is the heat balance of a Martian building? Houses are not very energy intensive, but the heat load from an efficient plantation may be quite high, for example. A greenhouse (or more aptly a grow house) in ice might be a significative challenge, at the lighting levels can reach hundreds of watts per m2. Intensive grow houses on Earth require active cooling. So you may have a cheap building, but if it requires constant active cooling and a radiative cooling system, it may not be the safest place to live.
Ice Dome Construction for Large Scale Habitats on Atmosphere Less Bodiesas attached with examples
I find this thread would be more fun and Amazing if we thought and planed for the larger scale installations required for 1 million colonists.We could skip the first 20 years, that are probably going to be systems that are prefabricated and come from Earth, and think about the longer term, large scale infrastructures?-Can you fit one million people and their food production systems in a glacier? How long will the heat sink last?-How far away can resources be?-What is the energy required?-How large will the spaceport be?-What will be the ground level infrastructures?-What is a good size for a community in the Mars environment?
It really depends on where on Mars the base is and what the local resources and circumstances are.For Hellas basin glaciers covered in a few meters of Regolith, assuming it's a relatively pure water ice glacier, maybe designs that consume the ice of the glacier, taking advantage of the thicker atmosphere in the Hellas basin. As the ice is consumed for ISRU propellant, oxygen and water, the void created might be living space. The regolith cap might be held in place both by mixing with water and freezing it and building support structure.There's room for very large underground spaces to be hollowed out since the glaciers are hundreds of meters thick and cover square kilometers. The roof over the space would be controlled architecture using regolith rather than depending on something like lava tubes natural roof. Since the roof is designed it could be strong enough to support suspended structures hanging from it.The space would grow as a side effect of consuming the ice anyway so the main design decision would be what shape to make the cavity.I picture a growing vertical space that gets to be over 300m deep before hitting rock. There might be a truss structure on the surface to allow suspending structures in the space. Eventually you could have a huge 3D space with structures coming up from the floor, suspended from the roof and built into the rock walls of the cavity.At Mars gravity with sea level air pressure flight is very easy so a main mode of transport in the space is flying. There are light airy buildings with 100 levels and lots of open balconies (that people can fly to) looking out on a vast 3D cityscape. Lower gravity, suspension from the roof and materials like carbon fiber allow pretty amazing architectural expression not seen on earth. You take an elevator to the floor which is parklike and includes lakes or the Mars surface above which is mostly industrial and utilitarian.No idea how stable the glacier is or how much it flows. I'm assuming there's a site where there's a buried Glacier that's pretty static by earth standards. The low gravity and lack of new snowfall ought to promote stability.I think any civilization on Mars depends on plentiful energy. Hellas is near the equator so good for solar. I think nuclear is needed anyway. I think the best middle term chance at building pleasant environments on Mars is with large open underground spaces that permit O'Neill colony like landscapes with trees and open water. Building within the voids creating by mining glaciers in Hellas might permit this with decent intermediate designs, in a space that's being created anyway and a location that has many advantages.If residents like the idea of natural sunlight, it can be collected on the surface and piped in. The roof isn't very thick and it's not difficult. The roof is sufficient though to protect against radiation.A single glacier in the Hellas basin could easily hold a city of million people in this mode. At some point it would start piping in water from other nearby glaciers and starting suburbs.I'm assuming that agriculture is just another industrial activity and is done in completely controlled environments with artificial light and works just as well in vertical stacks 300 meters high underground as anywhere.
There's a third group of people, the ones that think Mars is not the solution.
None of the flaws in the ice house or any other ice based structure such as inside a glacier have been addressed, the living space inside is simply uncomfortable and high maintenance on par with living in an arctic region, if your going to go to the trouble of making an enclosed space with breathable air and temperatures still substantially above the outside temperature it makes little sense to not go all the way and go to a comfortable indoor temperature.If people want to speculate about million inhabitant level construction methods then I will give you my take. It will consist of an arcade https://en.wikipedia.org/wiki/Arcade_(architecture) of columns and groin-vaults several stories tall and covering the ground in all directions as it grows at the edges with the first meter or two of regolith on the ground being used to make each addition. The column interiors are regolith as is a covering over the top of all the vaults for radiation protection. Some form of plastic, carbon-fiber or basalt fiber made from local materials is jacketed around the column to give it tensile strength and forms the vaulting as well. Between the columns of the arcade a lattice works connect to the columns and form floor joists onto which thin bubble pressure vessels are inflated and connected to each other. Heavy systems like liquid storage is at ground level and some kind of light-rail tram system provides horizontal transport while elevators and stairs provide vertical transport.
Inside that space you have a second chamber, lets call it a 'conservatory', which is insulated with aerogel on the inner surface of the ice so to can be warmed to 20C. This be used to grow plants and as space to hang out.
(Reposting from general discussion thread) Here's my vision for amazing habitats on Mars. I imagine networks of cliffside cities with many panoramic windows dug out from mesas, natural canyon walls or even Tatooine-style dugouts, featuring: - multiple levels, - dozens of windows and dome-covered verandas with panoramic views, - excellent protection from radiation,- robustly stable indoor temperatures, so one less thing that can go wrong,- shirtsleeve access via tunnels to surface facilities above or nearby (e.g. power generation, greenhouses, landing pads), - redundant protection from decompression with segments protected by automatic airlocks,- grand and inspiring elaborate carved entrances with inspiration from all ancient cultures on Earth,- direct shirtsleeve access (via tunnels / airlocks) to mines for resource extractionBesides excavation equipment and the usual internal equipment needed for habitats, the following will be needed: - a scalable and flexible solution for a flooring and false ceiling system that can eventually use in situ resources, - a scalable solution for sealing excavated tunnel surfaces that can also eventually use in situ resources (some kind of epoxy?), - automatic airlocks and door systems to separate segments for safety, - a modular system to create windows or external domes to cover "verandas", also evolvable to use in situ resources for the future.
Quote from: Impaler on 10/12/2016 08:32 pmNone of the flaws in the ice house or any other ice based structure such as inside a glacier have been addressed, the living space inside is simply uncomfortable and high maintenance on par with living in an arctic region, if your going to go to the trouble of making an enclosed space with breathable air and temperatures still substantially above the outside temperature it makes little sense to not go all the way and go to a comfortable indoor temperature.If people want to speculate about million inhabitant level construction methods then I will give you my take. It will consist of an arcade https://en.wikipedia.org/wiki/Arcade_(architecture) of columns and groin-vaults several stories tall and covering the ground in all directions as it grows at the edges with the first meter or two of regolith on the ground being used to make each addition. The column interiors are regolith as is a covering over the top of all the vaults for radiation protection. Some form of plastic, carbon-fiber or basalt fiber made from local materials is jacketed around the column to give it tensile strength and forms the vaulting as well. Between the columns of the arcade a lattice works connect to the columns and form floor joists onto which thin bubble pressure vessels are inflated and connected to each other. Heavy systems like liquid storage is at ground level and some kind of light-rail tram system provides horizontal transport while elevators and stairs provide vertical transport.Nobody is saying that habitats in ice would need to be cold. Insulating walls really isn't rocket science, even your deep freezer manages this. My house has snow on the roof in the winter without being cold inside. Polyethylene can be synthesized from hydrogen and carbon, you wouldn't even have to bring it.Building big pressure vessels is HARD. Really. Drilling into rock or melting into ice gives you the big advantage of not having to build pressure vessels because you have all the weight of the ice or rock on top to counter the pressure. This weight comes for free, it's already there.And with "pressure" I mean 10 tons for every square meter of your arcade trying to rip it apart from the inside. The tension the walls have to keep up against goes up proportionally with the radius of the vessel. Plastic just isn't going to work, you'll need aluminum or steel or carbon fibre, and lots of it. And you will have to build it as a sphere or a cylinder, because it will pop out immediately otherwise. And the smallest weakness somewhere can make it fail catastrophically.And you will still have to insulate it, because the regolith on top and beneath and with it the skin of your building will be at the same temperature as the ice in a glacier.
Moving my post from the IAC thread here.Glaciers may move on Mars but sure at a much slower rate. The ice is much colder and harder. Also forces moving them are smaller. On earth glaciers move because they are on a slope or because there is new precipitation which produces thrust. Both would be absent or much smaller on Mars.Habitats could be well insulated houses. The caves in the glacier could be very large so heat from the habitats can dissipate into the glacier without causing melting. The caves would be pressurized so people could be outside without spacesuit though they would need heavy arctic clothing. If temperatures could be kept at -10-15°C and the air dry, being outside could be even fun with little air movement. This would likely not be the only type of habitat but it could be one option.I have visited a salt mine with huge caves. That should look somewhat similar and it was gorgeous.
I'd have to think that insulating the face of the ice from the settlement's air temperature isn't that killer an issue. A settlement with reactors and waste heat anyway could keep a huge volume at a very comfortable temperature. Reactors could be located in the rock a short distance away.