Lunar Scenario Study

arobie · Nov 26, 2006

I would like here to do a thought experiment. This is part of an overall plan to expand into space by utilizing the resources we have out there. Of course I hope it's agreed that we need to expand and develop our presence into space (if it is not, the argument is for another thread <img src="/images/icons/tongue.gif" />), but expansion is not feasible if we have to send everything up from Earth. The cost is just too great from the Earth's surface. Instead we need to find and use the resources that are already sitting above the Earth's gravity well to help us along the way. We need to take advantage of the oxygen, the metals, the silicates, the water, etc. that are already in space. I'm taking a look at the Moon, our own Luna. While "Magnificent desolation", there are resources there for us to use. For example, in the Lunar Highlands (the light areas we see when we look at the moon) a mineral "Anorthite" is abundant. At the landing site of Apollo 16, the average concentration of anorthite was 75%-80% and up in places to 98%.Anorthite is (Ca Al2 Si2 O8). It can be processed for the Aluminum, Calcium, and Silicon with oxygen being the free byproduct. Oxygen is probably one of the most important resources we can get from the Moon. Not only is it essential for our survival, but it is also 8/9 of the mass of our most efficient rocket propellant, hydrogen oxygen. The hydrogen would have to be imported from elsewhere, most likely Earth because hydrogen is very rare in lunar regolith. Unless(!) there were water on the Moon. Water would be the most valuable resource that we could find on the Moon, and this is what I want to examine. In fact, the lunar prospector mission did find water on the Moon at the poles. The figure stands at 10 - 300 million tons of water ice. There is a huge margin there because the spectrometer could only detect down to a certain depth (0.5 meters), whereas there is most likely to be ice below that depth as well. Despite the huge marg

qso1 · Nov 27, 2006

I think its generally accepted that the moon is the ideal place for a lot of logistical staging of exploration and commercial activity. You mentioned many of the reasons for why this is thought to be a good idea. And you brought up the important question of what it would cost to access lunar hydrogen. Unfortunately there is no way to know the cost at this time and I realize its a thought experiment but any scenario could be suggested which will result in a wide range of cost estimates. We have to establish the very first leg of the infrastructure, which is just getting back to the moon. Once that is done, it will then become a little clearer as to what type of operations are actually required, and how we will set up those operations. It should also be noted that private enterprise/industry will play a major role if they achieve success in lowering the cost of access to low earth orbit. And at this time, it would be very difficult to estimate what it would cost to support any sort of lunar operations conducted under private industry/enterprise but one thing is for sure...it will be contingent upon profitability. <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

webtaz99 · Nov 27, 2006

Guess what - even the process of getting oxygen from anorthite requires hydrogen. <div class="Discussion_UserSignature"> </div>

nexium · Nov 28, 2006

The average private home or office has a ton of chemicals and equipment, but can make few or no elements from rock or salvage stuff. The bottom line is it takes a ton or more of specialized equipment to make a pound per day of most elements. Some compounds (and mixtures) can be made with little equipment, but most are not what we need in a space colony as they are similar to sand, regroth and rock. Also most process are efficient only with concentrated ore. The concentration equipment is also bulky with high mass. Each small colony likely needs to specialize in one high tech proceedure or a few medium tech, but then we require transportation infrastructure between thousands of colonies as there are thousands (perhaps millions) of more or less essential ingredients to being self sufficient. ie If you need three millimeter screws, you can adapt to two millimeter screws which you have, except you will likely create a need for something else you don't have, by making the change to two millimeter screws. My guess is transportation is slow, but simple between asteroid colonies millions of miles apart compared to lunar colonies a few miles apart. Neil

shadowsound · Nov 29, 2006

While what we want is to be able to be self sustaining in refinement operations and housing of humans in colonies we need to put in place, as someone indicated, an infrastructure. Since I have worked in the industry I see the affects that infrastructures have on promoting development. the first I would put in and in my opinion the cheapest is communications. Have spoke on this to various people and in various forums but I'll describes it again. We need to establish a GPS Communications system around the moon. this because the Moon has no poles and itis need to reduce the overall costs of navigation's. It can have Landsat capabilities that woudl make it valuable as a research tool, and overall navigational safety. This need to the connected to earth orbit with a Broadband optical communications link. Talking terabytes. that allows all venture to the moon to communicate freely to the earth instead of need a massive amount communications equipment on the moon and the earth. this brings down the overall cost of future missions. the last component is a space-ward looking receiver system to receive the comm from the moon all this will will spur future missions because of the reduction of safety hazards, and remote control of unmanned missions, via an Internet type system. Log in and operate it from anywhere on the Earth in Earth orbit in Lunar orbit or on the moon. It is the one thing that a couple billion dollar or less could be invested to to reduce future development costs. It could be done by a private company who would change for communicating and monitor by anyone on the earth the terrain of moon or on going projects. As to the many products needed by the moon initially we think about things like hydrogen in forms of gases and liquids . Why not create a composite neutral product in a solid form that can be launched in the cheapest form from earth to the Moon something like packing a ca

arobie · Nov 30, 2006

qso1, I apologize, I didn't quite make myself clear. In fact, looking back, I didn't make myself clear at all in this respect which matters. I meant mainly examining the Delta-V and therefore propellant costs of such an operation. For Example... Starting on Earth, we have to launch to the Moon the equipment for the mining. I'm not going to worry about a colony yet just to keep it simple. Later, after I do some preliminary calculations, I will add the complexities of the colony as well. I just want to see the delta-V, propellant mass, and equipment mass trade offs between what we send from Earth and the mass of resources that could be produced on the Moon and how many launches, with a given launch capability, it takes for them to even out and become profitable in terms of mass produced and mass sent. So I am examining two basic scenarios, one at which we have the lunar ice at the poles, and the other where we do not and instead get oxygen from regolith at the equator. In the lunar pole scenario, it would probably be best to make use of EML-1 to send propellant to for a re-prop station, but that might not be the case in the equatorial scenario. I think first, I need to post some delta-V figures. kadetken made an awesome post of cis-lunar dVs a while back. Delta-Vs in Cislunar Space As evident, it is a list of delta-velocities. For easy reference, I will copy it here to see ------------------------------------------------------------------------------------------------------------------------------------------ Delta-Vs in Cislunar Space Someone had asked earlier about delta-Vs for maneuvering around up there. The following are from "Human Spaceflight: Mission Analysis & Demand", Larson & Pranke, eds. ISBN: 0-072-36811-X. <</safety_wrapper>

mdodson · Nov 30, 2006

I hope that you've caught the news in the past month of the dispute as to whether or not to expect ice to be at the poles. HEEO has the advantage of being stable, as opposed to EML-1 or 2. John Lewis, in "Mining the Sky" gives several reasons reasons why utilizing asteroidal material would be a better choice.

owenander · Nov 30, 2006

Asteroid's would be better because there is no gravity at all so no energy to liftoff after mining resources. Plus, we need to be mining metals so we can produce larger ships etc. Relatively speaking oxygen and hydrogen are not very heavy. It would be much more efficient to mine to heavy stuff in space earlier.

barrykirk · Nov 30, 2006

There are ice comets that have plenty of Oxygen and Hydrogen. So, they should be relatively easy to mine.

annodomini2 · Nov 30, 2006

While I agree in principle comets/asteroids would be a better source of resources, its putting these bodies in a position more acceptable to mine. Given most of these (local) bodies are in the kuiper belt, there is a significant amount of energy (i.e. fuel etc) required in either moving the bodies themselves into a position suitable for mining or moving equipment to and from said bodies to put these resources in a suitable position for use, therefore the moon (while at this stage assuming the water exists there) becomes a more promising target due to its proximity. If the moon doesn't support these resources then its a question of the Earth and the Comets and the balance of resources. Another thought in assuming sufficient resource on the moon, the gravity of the moon may provide a more optimum balance in aquiring these resources as existing technology from earth may be more adaptable to operating on the lunar surface, rather than a complete redesign required for operating on a very low gravity rock. Not to mention if human access is required to said resources as the moon's gravity provides a more adaptable operating environment for people. <div class="Discussion_UserSignature"> </div>

rocketman5000 · Nov 30, 2006

Comets come into the inner solar system all the time. Maybe collecting water would be as easy as bringing a collector spacecraft into the tail and opening a large scoop.

mrmorris · Nov 30, 2006

" Maybe collecting water would be as easy as bringing a collector spacecraft into the tail and opening a large scoop. " It is imperative that we always remember our arch-nemesis: Delt A. Vee. The omnipresent Mr. Vee is the bane of most space scenarios. Consider the Rosetta mission -- conveniently portrayed in an article today in Spacedaily. At a relatively modest mass of 3000kg, it was impossible for ESA to send it directly to the comet because of the incredible problems of matching velocities. Instead, it's taking a path that will include four planetary swingbys and ten years to match orbits. 3000kg isn't all that much mass if you're talking that much water, and it wouldn't include structural mass or propellant mass even then. What the *worst* thing though when you look at Rosetta in relation to cometary water runs is that the mission doesn't even come back. Once our craft has reached the comet and sucked up some H20... it's going to have to push a *bunch* of mass back to the moon and the change in velocity required is just as big going the other direction. To have any chance of success, the mission would have to be able to refill from the comet. Let's work with that. We'll assume that the 'Water Tug' (henceforth WT) uses Hydrogen and Oxygen (either as LOX/LH2 or possibly nuclear-thermal expelling heated H2O). So the WT goes out to the comet -- fills up its water tanks and propellant tanks (possibly one and the same), uses up X percentage of it getting it back to the moon and then dumps the rest into the lunar reservoir. Except -- to get out to the comet in the first place -- it had to have enough water in the tanks to get there (presumably pulled from the lunar reservoir)... and likewise it has to leave some water in the tanks to make another run. So how much is left over?

j05h · Nov 30, 2006

> Given most of these (local) bodies are in the kuiper belt, Most of them may reside in the Kuiper Belt, but there are plenty of NEOs, including some with very low Delta-V, that appear to be dead comets. Apophis is a possible water-rich candidate, there are others and some of them are energetically easier to get to than the Moon. The Apollo and Aten asteroids (Earth-crossing) are the first logical targets for resource extraction. Looking at the Kuiper Belt and thinking "it's to hard to get there" does you no good. The resources are much closer. The progression I see is NEOs then Inner Belt, then gas giant moons and Trojans. As a company/enterprise, you really only need to find one water-rich body to make bank, the closer to Earth the better. Needless to say, I am very skeptical of the Lunar water claims. It would be easier to make your own gravity (spin-G) on/orbitting a dead comet than deal with the operational issues of lunar mining. If you need gravity for material processing, set that up as the counterweight to your habitat and remotely control the onsite mining ops. I don't think moving whole asteroids/comets into Earth orbit will make sense for a long time. Any materials used in space will be delivered as processed stocks (water, slag, metal, volatiles), then refined and distributed. The technology for mining and shipping is a lot closer to hand than moving whole bodies. Will it happen? Eventually but it is much further in the future. josh <div class="Discussion_UserSignature"> <div align="center">We need a first generation of pioneers. </div> </div>

shadowsound · Nov 30, 2006

It sound like you haven't been keeping up with the asteroid Ceres. If the science is right then it has more water in it than all the oceans of Earth. Its gravity being so low you can use it but part a tanker bladder near and just fill it up for transport to Lunar Orbit or maybe crash it in that location at the pole at low speed. That give water, Hydrogen and oxygen.

MeteorWayne · Nov 30, 2006

Again, getting out to Ceres and getting back requires a lot of energy. It is beyond Mars, and the success rate of missions to mars isn't great. That's more challenging in some ways (energy out and back) and less challenging than earth crossing asteroids in others (close, but a big speed match problem). Besides, if we stole water from Ceres, we might have to stop calling it a dwarf planet <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

mrmorris · Nov 30, 2006

"...the asteroid Ceres. If the science is right then it has more water in it than all the oceans of Earth. " This is a 'possible configuration' based on nothing more than its relatively low density and computer modeling. Saying ''If the science is right..." indicates this is the accepted theory right now. That's not the case. It's a possibility that's been put forth by one research group. Their computer model indicate a dense core and lighter material on top. There are several possible explanations... it just so happens that the most exciting would be a water core.

MeteorWayne · Nov 30, 2006

It seems more likely that there would be a rocky core and an icy mantle, since Ceres is large enough to have reached hydrostatic equilibrium. Therefore it would have likely differentiated by density. That was one of the major arguments for it's inclusion in the planet class. <div class="Discussion_UserSignature"> But the Krell forgot one thing John. Monsters. Monsters from the Id. I really, really, really, really miss the "first unread post" function </div>

mrmorris · Nov 30, 2006

"It seems more likely that there would be..." I don't know enough about planetary formation theories to make any educated statements about what the composition of Ceres might be. I do pay enough attention to what I'm reading to be able to determine what's actually being said in an article. It's fairly obvious that this one is using the most sensational possibility (however unlikely) of the study to spice up what would otherwise be a rather dry article about a new computer model that predicts Ceres has a high-density core and low density mantle. Good journalism. Bad science.

rocketman5000 · Nov 30, 2006

My use of easy was in relation to the method of extracting water, not to the retreival thereof. I realize it would be a highly energy intense mission. An NTR would likely be the only possible method of making the trip and returning with anything work the expense of going there. Using the rocket equation I should be able to work up a table perdicting the percentage yeild of a mission as a function of required Delt A Vee and initial mass of spacecraft.

mrmorris · Nov 30, 2006

"My use of easy was in relation to the method of extracting water, not to the retreival thereof." My bad. So you meant that once we ignore the transporation elements of such a mission that we know will be hard... the actual process of extracting water from a comet (about which we really know nothing) will be easy. Gotcha. <img src="/images/icons/smile.gif" />

rocketman5000 · Nov 30, 2006

No, I was refering to being able to collect material floating in a tail of a comet would be easier (read less complex) than trying to collect it by landing on the surface (active with geyser, outgasing etc), drilling, liquifying it to pump into tanks taking back of from the surface and departing. By collecting the material from the tail it wouldn't neccessarly be a requirment to exactly match the comets velocity, but rather have a low difference in velocity so that the space craft would linger long enough to pick up an adequate amount of material for the return trip.

mrmorris · Nov 30, 2006

"No, I was refering to being able to collect material floating in a tail of a comet would be easier..." Check out the Stardust mission. Try to determine what percentage of the materials captured in the aerogel when it passed through the Wild-2's tail was water.

owenander · Dec 1, 2006

Stardust mission was pretty far away for safety, if they had gotten closer probably would have more h20

mrmorris · Dec 1, 2006

"...if they had gotten closer probably would have more h20" This is the last post I'm going to make on this subject both because it's hijacking the thread and because it's getting ridiculous. Sit back and give the situation some thought. The comet is in space -- which is to say in vacuum. Liquid water doesn't hang around in a vacuum very long. Water in open space will either be ice or vapor. So any water trailing behind a comet is going to be an either/or. If Wild 2 were trailing a bunch of ice crystals, then there should have been multiple tracks in the aerogel with essentially nothing in them as the ice wouldn't have lasted all the way to the lab. I've not heard of this and I'd think it would be rather big news. This isn't surprising, as the more likely state for the water to be in is vapor. After all -- presumably it just outgassed from the comet, so would be unlikely to refreeze until it makes it into the shadow of something. Also -- what creates the tail is the solar wind. Said wind is very weak... which means that the items being pushed behind the comet (or ahead of on the trip back out) are very very very light. The tails are not a firehose of liquid water or ice just waiting to be picked up by enterprising spacefarers. They are, at best, a thin cloud of water vapor mixed within a cloud of dust particles. The tanker in question, flying behind (or ahead of, I suppose) the comet would have to capture the vapor (how?), remove all the troublesome dust (how?), condense the result into liquid water (how?) at least, or preferably ice (less trouble to accelerate a solid than a liquid), then get it back to the moon. And this is the 'easier' part.

spacester · Dec 2, 2006

Wow, is there even one post here that directly responds to the proposed thought experiment? Nope. I just double checked. What a joke, has this place degenerated that much? Come on people, you can do better! *** Is there nothing in Arobie's post to talk about? Where does the H2 come from if not the poles? How definitive is the latest info indicating the poles are dry? If the poles are wet how hard is it to coordinate with an orbital re-prop station? Is that station in a polar orbit? Equatorial orbit? HEEO? HELO? L1? L5? <div class="Discussion_UserSignature"> </div>

Lunar Scenario Study

arobie

Guest

qso1

Guest

webtaz99

Guest

nexium

Guest

shadowsound

Guest

arobie

Guest

mdodson

Guest

owenander

Guest

barrykirk

Guest

annodomini2

Guest

rocketman5000

Guest

mrmorris

Guest

j05h

Guest

shadowsound

Guest

MeteorWayne

Guest

mrmorris

Guest

MeteorWayne

Guest

mrmorris

Guest

rocketman5000

Guest

mrmorris

Guest

rocketman5000

Guest

mrmorris

Guest

owenander

Guest

mrmorris

Guest

spacester

Guest

Similar threads

TRENDING THREADS

Latest posts

Share this page