I thought about microwave, but then you need line of site, satellites or surface boosters. All of which could slip and before you know it, you have alot of energy frying alot of equipment or people.<br /><br />On the charge of the regolith, I would guess that it is positive considering the intensity of UV and higher energy photons hitting the surface the charge would be positive. So you could generate a charge on a metal sheet, with a plastic sheet between that and the regolith, you could hold the dust to the sheet. Make the plastic sheet a conveyor belt and you might be able to make it drop off. It won't work for heavy particles though. A device like that would also be vital to keeping the habitat clean of dust. <br /><br />That is what we need, devices with multiple uses, lots of modularity, redundancy and scalability.
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A lunar vacuum cleaner?? I like the idea. A repulsive charge could work for keeping camara lenses and helmet visors clear right? I read Apollo had problems with clouding camara lenses. <br /><br />To keep dust from getting into the habitat you could have systems similiar to airport bomb sniffing that fires jets of air at you to dislodge explosive particles and use an Ionic Breeze to clean the dust from the air!!! I knew watching informercials had an upside...
Please allow me to talk yet again about the lunar dome strategy I've been working on, in the context of construction equipment.<br /><br />I've been looking for a construction method that will minimize the landed mass needed to get started, and is consistent with the steady arrival of additional landed mass. Dropping a big bulldozer down first thing would be pretty much the opposite of what I have in mind.<br /><br />My basalt dome would be built on the flat lunar maria, which are massive basalt flows. The quarry site would be nearby the dome site. The dome would be sealed with glass, so that capability needs to be developed first, but other than that, the first step is to prepare the site.<br /><br />If we build on a flat expanse of basalt, we don't have to move a lot of regolith right away. All we have to do is clear the site.<br /><br />Dust is going to be a factor up there. But if we remove all the dust from our work area, we can make a lot of the problems go away. Once we move it out of the way, it's not gonna blow back into our work area.<br /><br />So the first construction robots in my plan are sweepers. Tele-operated and modest in size and power, these robots would prepare our dome's site, taking whatever time we decided was most economical to get 'er done.<br /><br />If we cannot afford the energy for large construction equipment, then I think we should choose a construction method that doesn't need them. I seek a construction method that can build a very large facility using very small robots.<br /> <div class="Discussion_UserSignature"> </div>
<p>First time poster so be gentle 
<br /><br />Looking for some concrete example of potential nuclear power supplies and came across the Toshiba 4S. It is designed to provide 10 MW for 30 years, and consists of a completely self-contained core, into which water is fed and steam is retuned. The core is buried undergound, with the steam turbines built above ground. After 30 years, the core can be replaced "like a battery", as discussed in the this <br />article about using one in an Alaskan village. Also from this artile:<br /><blockquote>The power comes from a core of non-weapons-grade uranium about 30 inches in diameter and 6 feet tall. </blockquote>Not sure if that is just the uranium, or the entire portion that is buried, but still sounds very transportable.<br /></p>
<br /><br />Looking for some concrete example of potential nuclear power supplies and came across the Toshiba 4S. It is designed to provide 10 MW for 30 years, and consists of a completely self-contained core, into which water is fed and steam is retuned. The core is buried undergound, with the steam turbines built above ground. After 30 years, the core can be replaced "like a battery", as discussed in the this <br />article about using one in an Alaskan village. Also from this artile:<br /><blockquote>The power comes from a core of non-weapons-grade uranium about 30 inches in diameter and 6 feet tall. </blockquote>Not sure if that is just the uranium, or the entire portion that is buried, but still sounds very transportable.<br /></p>If all you are using is water, or LOX/LH2 it would be pretty cheap. Being able to transit fairly long distances would be an asset. I would imagine you could easily get from any location on the moon to another in a single jump. Even on Mars you would probably have pretty good range.<br /><br />No matter how you do it you have to have a power source. What kind of range would a surface transport have? Where would it re-fuel? It would have to be independent from a reactor and you can't have a reactor every hundred miles. Any other propellant choices have downsides. Hydrogen and Oxygen, either as gasses, liquids and eventually solids, are the best option. With that in mind it is much simpler to default to Hydrogen/Oxygen for all applications. The requirement of water for biological needs emphasises the need for water anyway, might as well take advantage of the situation.<br /><br />Use a jump vehicle and you land and service the local transports as needed. One thing to remember only the water used for the jump is lost, surface vehicles and Stations would recycle a much water as possible. <div class="Discussion_UserSignature"> </div>
China is also planning on building a bunch of nuclear 'batteries' and they are going to seriously(1000s) mass produce them. Problems still remain of getting it to the surface. However long they expect it to last, being on earth is massively different to being in space. The cost is also huge and the whole system is not scalable using in-situ resources. <br /><br />You rely on earth, and the politics might significantly change. Such a colony would take until until 2020 to start construction and then if, all works well, it will be 2050 by the time you need a refuel. Now america might not be manufacturing such nuclear batteries and the only alternative might be china. China might have a base and don't see the point of supporting an american science colony. They just don't have to sell you the uranium and you will need to leave the moon very quickly before you freeze next lunar night.
But we don't know how much water is on the moon. The amount of water would definitly be less than the amount of oil on earth, and see how quickly we go through that. It might last for a few hundred years, but I like to look at the seriously long term. <br />I'm the sort of person that when he hears that He3 from the moon will last us for 1000 years, immediatly thinks that is nowhere near long enough.<br /><br />Also hoppers wouldn't help you build up the infrastructure that a rail or road system would give you.
I don't know if this has been brought up before but why build on the moon? Why not build under it? Excavate a shelter 15 to 20 meters down with an elevator shaft leading to it. The only thing on the surface is the docking port which also serves as the Solar panel control center and communications hub.
I think it would be much better to dig the quarry, turn the basalt into glass and build the dome in the hole. The robot idea also works as long as you use water for power. <div class="Discussion_UserSignature"> </div>
The only water expended is that used for propulsion, I would think we could give up some of our oceans to get off the planet.<br /><br />Last time I looked Kerosene weighed about 6.75 pounds per gallon and LOX 14 or so pounds per gallon, if I remember right! Water weighs 8 pounds per gallon and comes with both the fuel and oxidizer. All you need is solar energy, hydrolizers and fuel cells.<br /><br />I would think rail or road systems would take quite some time to establish. It would be fairly simple to boost off the surface in a ballistic tragectory and land at a destination, the higher your boost the further you travel. <div class="Discussion_UserSignature"> </div>
With global warming we might want to get rid of some of our oveans.... that might take a few launches though. <img src="/images/icons/tongue.gif" />
ISRU is a critical component to building a sustainable infrastructure in space. However, one of the key components to doing this in having the bootstrap effect - if we had to build everything using materials we found on the moon, we would never be able to get moving, as all of our efforts would be bare subsistence survival. On the other hand, if we use things from Earth that provide a capability that will be difficult to create on the moon that enable large jumps forward, to build infrastructure and capability and enable more advanced ISRU, we have mad a good tradeoff. <br /><br />My thought is that, assuming we can even get one of these devices (which is a big if), they provide an immediate boost to the capabilities of the settlement, as we will not initially be energy resource limited, so we can do things like operate manufactuing at night, have high power construction machines (bulldozers, cranes, etc). This allows for quickly building living and industrial capabilities, potentially enabling the relatively fast production of solar panels that, over time, could gradually replace the nuclear power as the primary power source. Or, in that time frame, it may be possible to build the infrastructure to build nuclear capabilities on the moon (or in space)<br /><br />Agian, this is based on the assumption that there is a nuclear power plant that is actually available that would be feasible to put on the moon. Given the political climate, that is a big if, and solar is probably a more reliable possibility to plan for. <br /><br />
It's a fully re-newable source of power on Earth, in Space there would always be loses but resupply could be planned for. Power needs would be met by multiple fuel cells that could be added as needed. The same holds true with hydrolizing and Hydrogen and Oxygen storage, as capacity needs increase more hydrolizers, solar panels and storage Modules are added as needed.<br /><br />Much simpler than Nuclear, instead of a reactor you have any number of fuel cells, feeding common electrical busses. One quits and the others picks up the load, the busses fail and each fuel cell will provide local power while repairs are undertaken and the system tied together again.<br /><br />I would think you would have to have at least two reactors anyway. ETOPS and single engine don't mix now. In fact I personally like at least three engines over water.<br /><br /><br />If it costs us some of the oceans to get into Space we can afford it, I doubt a measurable drop would occur for quite some time. <div class="Discussion_UserSignature"> </div>
Heee's baaack.<br /><br />So are you now saying that there is the resistance to be overcome? Try telling any designer of transportation vehicles that air resistance is not important on earth. Even using the the most friction free surface we can practically use at the moment, the energy lost to resistance will be significant. Also you need resistance in order to accelerate the vehicle, so you would at least be losing energy.<br /><br />We expect people to be more careful when writing out mathematical equations. In normal writing typos are to be expected, although you seem to make a significant number. Are you really sure that those meteorites will hit the moon at 15-25m/s. I can't be bothered to do the maths, but dropping anything from around 100m on the moon is going to hit the moon at around 15-25m/s. If you mean 1.5km/s then that is more understandable and you should realise that a few/tens of m of regolith is not going to give you a whole lot of protection.<br />Also many of the plans call for a polar site, which will dramatically decrease the chance of being hit by a meteor shower.<br /><br />Funny how you say that equipment could be presicely engineered in order to reduce the energy required, then you say that you need a nuke to power the 1000hp digger you propose, which one be one of the most inefficient systems. How about you cut out small blocks of material, and place them on a trebuche. You could easily move them a km without any more power than is required to slowly move the main mass a few m higher.<br /><br />The point of microwave sintering is because it can easily make the regolith airtight. I'd like to see you use heat from the sun, to sinter the walls of you tunnel. Also microwaves are very efficient at transfering energy into the regolith due to all the iron spherules. I think that many times, we have suggested using a mirror for purposes similar to this one. Well done, you have just made an argument for a modular piece of equipment.
Here's my thinking about flying rocks, starting with large rocks with high impact velocities.<br /><br />Impacts on the moon these days are few and far between. They are a real hazard. They are also a completely unpredictable hazard, yet deterministic in the sense that if we knew the orbits of all the rocks out there, we could pick a spot that shows no future hits. Unknown yet deterministic, a rather odd hazard in engineering terms actually.<br /><br />One might decide to simply treat it as a completely random hazard. If it's big enough to cut out a 100 m crater and it hits at your site, it's going to be a bad day no matter what you're living in.<br /><br />So basically, if you decide to live at a particular spot on the moon, you're either going to be safe or you're not. I've not time right now to present this logic in more detail.<br /><br />The above is talking about large rocks with high velocities. There is of course also, primarily actually, micrometeoroids, which are a frequent hazard.<br /><br />Every Habitat design is going to make a choice as to just how much incoming energy they are going to defend against. You're going to look at your design and you're going to state that you can withstand an impact of thus-and-so; anything bigger and faster than that and you are in deep doo-doo.<br /><br />So, if you're looking to increase your odds as much as you can, what you're looking for is a building technology that minimizes the random hazard by maximizing the thickness of your walls. I propose a dome built from Basalt with regolith piled on top.<br /><br />I propose building a facility that is large enough to protect the inhabitants from all but the largest meteoroids.<br /><br />As it turns out, if the idea is to build a very safe facility, you're going to be sizing your wall thickness on radiation blockage. IOW to get to near-Earth levels of radiation exposure, you're going to pile on enough regolith to not be worried about any but the largest and fastest flying rocks.<br /> <div class="Discussion_UserSignature"> </div>
Your reply reminds me of a project I worked on while in college. We examined using piezoelectric motors, but the price was way too much. <br /><br />The lifting capacity to system weight ratio is far superior to many other alternative systems for heavy lifting. Piezos also offer better system reliablity than hydraulics would. I would hate to have to fix a hydraulic leak on the lunar surface. I'm having a little trouble finding the power requirements however of the motors though. A nice effect of piezos is that they can recover energy when recompressed. Another drawback is the restriction to linear motion in most circumstances, this could be designed around using a crank system.
Cool, what was the piezoelectric material that you used? How long ago was this, as there might be better materials out there.
<blockquote><font class="small">In reply to:</font><hr /><p>As usual, the simplest and most effective methods get ignored, while the unworkable and impractical get the hoopla.<p><hr /></p></p></blockquote> <br /><br />Correct me if I'm wrong but you seem to favour simple approaches over complex ones.<br /><br />Since nuclear reactors are complex, what's wrong with the simple approach of sticking the base at the poles where light is available ~98% of the time and using that heat to drive the turbines?<br />
Well firstly I do know a reasonable amount about nukes. You could build a nuclear 'battery' which would be relatively self contained a could work for a period of time. But even the most reliable ones now need maintanence, which would be very hard on the moon. The repairs could not be manufactured on the moon so it would cost alot and you will rely on equipment from earth.<br /><br />So you suggest that you dig the tunnels by cutting down tens of m into the regolith and the covering it up again, once finished. That would require moving thousands of tonnes of regolith. It would be faster and more efficient to dig a single tunnel and then remove the regolith that you don't need. The energy saved using this method, would more than make up for your suggested method.<br /><br />I read recently in Wired that some guy built this solar energy system that concentrated the sunlight onto a small solar cell, and the result was far cheaper than the equivalent of PV. Of course this system depends upon how much infra-red energy is also reflected, but it seemed to work. See, you could use such mirrors for multiple purposes.<br /><br />Also you are assuming that photo voltaics won't improve in the time before construction starts. For example amorphous silicon cells are more efficient than crystalline cells and require less silicon. You could dope carbon nanotube ribbons, which could allow cells a hundred nm in depth. Such a sheet would only weigh a few kg per km2 and would be very easy to manufacture.<br />Optical rectennas could also become a possibilty. Once someone develops a single molecular diode, you you could attach it to a carbon nanotube, and the result is a rectenna that you can tailer for a specific purpose (depending upon how long the CNT is), you could build a camera that powers itself.<br /><br />So you have cells with up to 90% efficiency that weigh only a few kg per km2, and can be manufactured using equipment, even simpler than current chip manufacture. The reason why you hav
In reference to the angle of solar panels, you miss out that you could angle a mylar reflector at an angle. This might be somewhat cheaper than angling the the cells, but then using vey light solar panels as I mentioned above might be even lighter than mylar.<br /><br />It will really not be difficult to increase the distance between panels, and building on a hill will improve the energy per area again. Considering how craters may mean water (also ideal sites for telescopes and material from the early solar system) and water on the moon is hugely valuable, it is likely that bases would be based around there. Due to the lower surface temperature, the temperature of the wires can be kept low and thus improving the conductivity.<br />Again using solar reflectors mounted on polar orbiting satellites will allow energy to be gained by solar cells parallel to the surface.<br /><br />The link you supplied has more to do with earths tilt during the seasons. Seeing as the power drops to zero for a couple of moths, could this be because the sun doesn't come up at all in that part of the orld during that period? I can't recall the moon having such an axial tilt, so the important part of that graph would be the bit where the maximum power is being generated.
chriscdc<br />"Cool, what was the piezoelectric material that you used? How long ago was this, as there might be better materials out there. "<br /><br />We looked at using the piezos, didn't as it was about 4 times our budget, but had good response times and force outputs, This was about a year ago now. I am sure that they field has greatly changed since then, and the cost might have come down since then... I haven't done much research on them recently.
<font color="yellow">"The major energy requirements for regolith/rock movement are lateral and vertical movements. "</font><br /><br />Vertical: E<sub>potential</sub> = mgh<br /><br />You will agree that the vertical movements on the Moon require only 1/6th energy of similar movement on Earth?<br /><br />Lateral: E<sub>kinetic</sub> = 1/2mv<sup>2</sup><br /><br />It takes the same energy to accelerate mass whether on the Moon or Earth, sure, but does even terrestial dump truck accelerate all the time? No. It <i>waits</i> while an excavator or a shovel fills it up. Then after acceleration it drives at nominal speed at the dump site during which the power requirement is just a fraction of full rated power due to need to only overcome friction. What does this obvious description obviously mean? It means that a dump truckt with 1MW engine doesn't need <i>continous</i> supply of that much energy. Because the faster moving regolith equipment probably have some way to store their own energy (batteries, fuel cell) then a 1MW of solar/nuke/whatever power can keep multiple amount of units with 1MW max rated power humming.<br /><br />And because we are operating on the Moon our dump trucks probably aren't powered by 12+ cylinder diesels but with electric engines instead. That means we have a good chance to capture great deal of energy via regenerative breaking, to perhaps an array of supercapasitors.<br /><br /><font color="yellow">"If you'd care to give an accurate and reliable estimate of how much extra energy moving a metric ton of regolith on the moon, compared to on the earth is from a frictional standpoint, then I'd be interested."</font><br /><br />LINK<br /><br />Even rolling friction is directly proportional to weight.
Sorry for misunderstanding what you meant I thought you wanted to defend your habitats from the rocks. Any rock of substantial mass travelling at 15-25km/s would punch through anything less than 10m of regolith easily. I know perfectly well that you could pile the excavated material on top of your tunnel, but you are still moving alot of material that needn't be moved.<br /><br />Your comment on mylar, is the same that moon hoax advocates use for saying why you could not use film on the moon. The mylar would not melt, expecially if it had a gap between it and the regolith. As long as whatever poles hold it up, have a large surface area to volume ratio, then it could easily radiate the heat away. The mylar already has this advantage, it is also reflective and so will reflect most of the heat anyway. The cold comment on the otherhand would be relevant if it wasn't for the ability to keep the mylar warm. The carbon nanotube ribbons I mentioned earlier can heat when conducting. Sure this would use power but by rolling the sheets down you reduce their surface area and so they radiate less heat. <br /><br />Is that really your argument against polar satellites? Many suggestions for lunar architectures call for a service module that stays in orbit. Spending a few kg on a km2 deplyable mylar mirror (yes it REFLECTS the light but you obviously misread that) wouldn't be too hard, there have been examples of this used in space. It would also serve a scientific purpose of studying solar sails for orientating satellites, as well as measuring the strength of solar wind etc. If you used the mirror itself to change the orientation of the craft, then you wouldn't have to expend any fuel. <br />If you couldn't find a hill that allowed all round communication then the satellites would be required for this purpose.<br /><br />Do you have any links relating to lower temps mean lower panel efficencies? It wouldn't be hard to maintain the temperature of the panles, using a small fraction of the
I've been thinking about lunar vehicles and you could easily build a lunar rover. If the rover is used to transport people over a lunar road, it could easily be a peddle powered to begin with, then it could use solar power or a fuel cell to keep it moving.<br /><br />You could easily wait to charge up a capacitor whilst a vehicle is stationary or get the energy back using the braking process.<br /><br />Also a method to decrease the launch weight of such vehicles. Simple struts could be manufactured from lunar glass. Place regolith in a mould and pass a microwave over it. Perhaps the mould could also be part of the structure.
I think production of LH2/LOX should be done in orbit and ferried down to the surface as needed. Solar array size would be unlimited and storage climate would be ideal. Surface storage would allow constant power availability and an infinite number of fuel cells would provide massive redundancy, something lacking in a Nuclear system.<br /><br /> <div class="Discussion_UserSignature"> </div>
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