# Is there any economic potential in space exploration/colonization? **URL:** \ **Category:** Great Debates\ **Created:** [January 3, 2005, 2:36am UTC](https://boards.straightdope.com/t/is-there-any-economic-potential-in-space-exploration-colonization/282778 "2005-01-03T02:36:08Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [January 4, 2005, 6:11pm UTC](https://boards.straightdope.com/t/is-there-any-economic-potential-in-space-exploration-colonization/282778/21 "2005-01-04T18:11:34Z")
> [@](#): > > And water? I already pointed out that hydrogen and oxygen was available. If you want water in space, you can cook up a fresh batch. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [January 4, 2005, 11:07pm UTC](https://boards.straightdope.com/t/is-there-any-economic-potential-in-space-exploration-colonization/282778/22 "2005-01-04T23:07:13Z")
> [@Little Nemo](#): > > I already pointed out that hydrogen and oxygen was available. If you want water in space, you can cook up a fresh batch. Errmmm . . . where, exactly, are hydrogen and oxygen available in space? I don’t mean, for instance, the hydrogen mantle of the Sun, or the diffuse clouds of hydrogen a Bussard ramjet might scoop up for fuel. I mean hydrogen and oxygen in accessible and usable quantities. Is there oxygen buried in the crust of the Moon? If so, how would you extract it? And then, where do you get the hydrogen? ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [January 5, 2005, 2:54am UTC](https://boards.straightdope.com/t/is-there-any-economic-potential-in-space-exploration-colonization/282778/23 "2005-01-05T02:54:18Z")
> [@](#): > > Is there oxygen buried in the crust of the Moon? If so, how would you extract it? The lunar regolith is 46% oxygen by weight. Tied up in silicates and oxides. So it’s going to take some energy to get. Hydrogen is much scarcer - about 1 ton per 1000 tons of regolith. However, it free hydrogen from solar wind, and it might be easy to harvest. Imagine a nuclear powered vehicle with a big fork on the end, driving around sifting and heating the soil. The process would release the unbound hydrogen and HE3. The hydrogen can be used to make water or rocket fuel in combination with Oxygen, and the HE3 can be shipped back to Earth for fusion fuel, assuming we get that working. The key is power. Methinks we’ll want to build some big-ass nuclear reactors on the moon. An excellent place for them. With enough power you can do anything - melt soil into glass for building materials and fibers, extract lots of chemicals from the soil, make water, dig tunnels, etc. The Moon may turn out to be an excellent place to colonize. There are giant rilles that are totally covered and insulated that might make great places for colonies. The moon is stable, and those underground tubes should last for millions of years. Seal up the ends, use power to melt the sides into glass to make them airtight, and you’ve got a lovely home maybe 75 miles long and thousands of feet wide. You could build a small city in one. And there is water ice on the moon - the lunar Prospector spacecraft has already discovered it at the poles. The question is how much. Maybe a little, but perhaps as much as six billion tons. The latest data indicates that there probably isn’t that much, though. Six billion tons implies vast sheets of ice hidden inside perpetually dark craters. The lunar prospector crashed into one of them hoping to kick up an ice plume that could be detected, but none was. Since then, other measurements from Earth have failed to pick up widespread signs of water. But that doesn’t mean the water isn’t there. Instead of vast ice sheets, it’s probably just distributed through the soil in granular form in the dark craters. So instead of 6 billion tons, perhaps there’s only a hundred million tons. That’s still a lot of water. 6 billion tons of water, by my calculations, is about 7,000 cubic miles of water. In comparison, Lake Superior contains about 3,000 cubic miles of water. So we’re talking about a LOT of water. Enough for millions of people. Even 100 million tons of water is enough to support a large population. And that’s just the water tied up as ice from comets. If you have to, you can extract hydrogen and oxygen from the regolith and combine it. ---
**Author:** ![Epimetheus](https://avatars.discourse-cdn.com/v4/letter/e/c4cdca/32.png) [@Epimetheus](https://boards.straightdope.com/u/Epimetheus)\ **Post date:** [January 5, 2005, 4:20am UTC](https://boards.straightdope.com/t/is-there-any-economic-potential-in-space-exploration-colonization/282778/24 "2005-01-05T04:20:30Z")
Let us not forget possible petroleum reserves in astroids and on the moon predicted by the theory of aboitic petroleum origins. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [January 5, 2005, 5:31am UTC](https://boards.straightdope.com/t/is-there-any-economic-potential-in-space-exploration-colonization/282778/25 "2005-01-05T05:31:15Z")
> [@](#): > > where, exactly, are hydrogen and oxygen available in space? Well, they’re there. Admittedly they’re not in the immediate neighbourhood. Comets have hydrogen and oxygen. And they’re low gravity objects so it’d be easy to strip resources of them. The downside is they’re most common out in the further reaches of the solar system like the Kuiper belt. But what’s a few billion miles? Seriously, the most likely way to collect these resources would be with AI-controlled ships. They’d make a long (one way) voyage out and then take up an orbit out around 40 AU’s. When they detect a likely comet, they’d give it a push towards the sun (remember gravity’s on out side here). A few years later, megatonnage of raw material arrives and we collect it. We have the technology to do this now if we wanted to. If it sounds “pie in the sky” it’s nothing in comparison to plans to mine Oort objects - now those are a long ways away. ---
**Author:** ![Shalmanese](https://avatars.discourse-cdn.com/v4/letter/s/45deac/32.png) [@Shalmanese](https://boards.straightdope.com/u/Shalmanese)\ **Post date:** [January 5, 2005, 4:44pm UTC](https://boards.straightdope.com/t/is-there-any-economic-potential-in-space-exploration-colonization/282778/26 "2005-01-05T16:44:33Z")
When you say 6 billion tons, thats like saying theres more gold in the ocean here on earth than has ever been mined. The problem is if it’s so sparsely distributed that it would almost certainly be unprofitable to mine. There would have to almost certainly be some sort of deus ex machina of the nanotechnology or free nuclear fusion kind to even posit doing things like extracting hydrogen from regolith. And, IMHO, most of the hype surrounding both of the aformentioned technologies is precisely FROM future geeks who need something to justify schemes like extracting hydrogen from regolith. ---
**Author:** ![Loopydude](https://avatars.discourse-cdn.com/v4/letter/l/e56c9b/32.png) [@Loopydude](https://boards.straightdope.com/u/Loopydude)\ **Post date:** [January 5, 2005, 11:11pm UTC](https://boards.straightdope.com/t/is-there-any-economic-potential-in-space-exploration-colonization/282778/27 "2005-01-05T23:11:05Z")
I just don’t see it. Not for a long, long time. My guess is Space Tourism is about the only thing we could expect in the next 100 years showing any significant potential for growth, but I’m not sure if that industry could survive the inevitable consumer recoil when one of the space habs/hotels goes “PHHHHTT!” and a small crowd of billionaires bites it. Margins are likely to be tight. I read someplace that building a rotating space station of the size pictured in Kubrick’s 2001 ASO would bankrupt the world economy. It’s just too damn expensive to get all the needed stuff into orbit, much less out of Earth’s gravitational influence, to imagine any kind of profit-driven industry. Net-energy-producing nuclear fusion, and the resultant endless supply of cheap liquid hydrogen and oxygen might help, but we need that technology first. Who can say when we’ll get it? Space elevators are all well-and-good, but what are they going to be built out of? Nothing extant fits the bill. Km-long carbon nanotubes are a nifty idea, but I’m not holding my breath until somebody actually can manufacture such a thing. Despite all the hype, that sort of technology could still be decades away for all we know. All the industrialized nations put together may not be able to afford a modestly-sized permanent moon base for research purposes, currently; or they lack the will and mutual respect to embark on such an endeavor. There’s no way private industry is going to foor the bill for something so massively expensive. Nope. Not in our lifetimes; or our children’s, probably. Maybe in a few hundred years. Pity I won’t get to see it; it would be so fun to visit Mars. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [January 6, 2005, 12:38am UTC](https://boards.straightdope.com/t/is-there-any-economic-potential-in-space-exploration-colonization/282778/28 "2005-01-06T00:38:21Z")
> [@Loopydude](#): > > Space elevators are all well-and-good, but what are they going to be built out of? Nothing extant fits the bill. Km-long carbon nanotubes are a nifty idea, but I’m not holding my breath until somebody actually can manufacture such a thing. Despite all the hype, that sort of technology could still be decades away for all we know. They **can** manufacture carbon nanotubes. The hurdle is to finding a way to manufacture them in sufficient quantity at low cost. But they are making real progress! From [http://en.wikipedia.org/wiki/Space\_elevator:](http://en.wikipedia.org/wiki/Space_elevator:) > [@](#): > > **Cable** > The cable [for a space elevator] must be made of a material with an extremely high tensile strength/density ratio (the limit to which a material can be stretched without irreversibly deforming divided by its density). A space elevator can be made relatively economically if a cable with a density similar to graphite, with a tensile strength of ~65-120 GPa can be produced in bulk at a reasonable price. > > By comparison, most steel has a tensile strength of under 1GPa, and the strongest steels no more than 5GPa, but steel is heavy. The much lighter material Kevlar has a tensile strength of 2.6-4.1 GPa, while quartz fiber can reach upwards of 20GPa; the tensile strength of diamond filaments would theoretically be minimally higher. > > Carbon nanotubes have exceeded all other materials and appear to have a theoretical tensile strength and density that is well within the desired range for space elevator structures, but the technology to manufacture bulk quantities and fabricate them into a cable has not yet been developed. While theoretically carbon nanotubes can have tensile strengths beyond 120GPa, in practice the highest tensile strength ever observed in a single-walled tube is 63GPa, and such tubes averaged breaking between 30 and 50GPa. Even the strongest fiber made of nanotubes is likely to have notably less strength than its components. Further research on purity and different types of nanotubes will hopefully improve this number. > > Most designs call for single-walled carbon nanotubes. While multi-walled nanotubes may attain higher tensile strengths, they have notably higher mass and are consequently poor choices for building the cable. One potential material possibility is to take advantage of the high pressure interlinking properties of carbon nanotubes of a single variety. [4] ([http://prola.aps.org/pdf/PRB/v62/i19/p12648\_1](http://prola.aps.org/pdf/PRB/v62/i19/p12648_1)). While this would cause the tubes to lose some tensile strength by the trading of sp2 bonds (graphite, nanotubes) for sp3 (diamond), it will enable them to be held together in a single fiber by more than the usual, weak Van der Waals force (VdW), and allow manufacturing of a fiber of any length. > > The technology to spin regular VdW-bonded yarn from carbon nanotubes is just in its infancy: the first success to spin a long yarn as opposed to pieces of only a few centimetres has been reported only very recently; but the strength/weight ratio was worse than Kevlar due to inconsistent type construction and short tubes being held together by VdW. (March 2004). > > Note that at present (March 2004), carbon nanotubes have an approximate price higher than gold at $100/gram, and 20 million grams would be necessary to form even a seed elevator. This price is decreasing rapidly, and large-scale production would reduce it further, but the price of suitable carbon nanotube cable is anyone’s guess at this time. > > The cable material is an area of fierce worldwide research, the applications of successful material go much further than space elevators; this is good for space elevators because it is likely to push down the price of the cable material further. Other suggested application areas include suspension bridges, new composite materials, better rockets, lighter aircraft etc. etc. And from [http://en.wikipedia.org/wiki/Carbon\_nanotube:](http://en.wikipedia.org/wiki/Carbon_nanotube:) > [@](#): > > Synthesis > Techniques have been developed to produce nanotubes in sizeable quantities, but their cost still prohibits any large scale use of them. Fullerenes and carbon nanotubes are not necessarily products of high-tech laboratories, and are also formed in such mundane places as candle flames. However, these naturally occurring varieties are highly irregular in size and quality, and the high degree of uniformity necessary to meet the needs of research and industry is impossible in such an uncontrolled environment. There are several methods employed to make nanotubes, such as arc discharge, laser ablation, and chemical vapor deposition (CVD). In general, the CVD method has shown the most promise in being able to produce larger quantities of nanotube (compared to the other methods) at lower cost. This is usually done by reacting a carbon-containing gas (such as acetylene, ethylene, ethanol, etc. with a metal catalyst particle (usually cobalt, nickel, or iron) at temperatures above 600 °C. > > \ > > **Current progress** > One application for nanotubes that is currently being researched is high tensile strength fibers. Two methods are currently being tested for the manufacture of such fibers. A French team has developed a liquid spun system that involves pulling a fiber of nanotubes from a bath which yields a product that is approximately 60% nanotubes. The other method, which is simpler but produces weaker fibers uses traditional melt-drawn polymer fiber techniques with nanotubes mixed in the polymer. After drawing, the fibers can have the polymer burned out of them to make them purely nanotube or they can be left as they are. > > Scientists working at the University of Texas at Dallas produced the current toughest material known in mid-2003 by spinning fibers of single wall carbon nanotubes with polyvinyl alcohol. Beating the previous contender, spider silk, by a factor of four, the fibers require 600J/g to break. In comparison, the bullet-resistant fiber Kevlar is 27-33J/g. > > In 2004 Alan Windle’s group of scientists at the Cambridge-MIT Institute developed a way to make carbon nanotube fibre continuously at the speed of several centimetres per second just as nanotubes are produced. One thread of carbon nanotubes was more than 100 metres long. The resulting fibres are electrically conductive and as strong as ordinary textile threads. [3] ([BBC NEWS | Science/Nature | Nano-team spins tomorrow's yarn](http://news.bbc.co.uk/2/hi/science/nature/3872931.stm)) [4] ([http://www.newscientist.com/news/news.jsp?id=ns99994769](http://www.newscientist.com/news/news.jsp?id=ns99994769)) > > High purity (80%) nanotubes with metallic properties can be extracted with electrophoretic techniques. [5] ([Home – Physics World](http://physicsweb.org/article/news/7/6/19/1)) > > In April of 2001, IBM announced it had developed a technique for automatically developing pure semiconductor surfaces from nanotubes. > > On September 19, 2003, NEC Corporation, Japan, announced ([NEC Global - Press Release](http://www.nec.co.jp/press/en/0309/1901.html)) stable fabrication technology of carbon nanotube transistors. > > In June 2004 scientists from China’s Tsinghua University and Louisiana State University demonstrated the use of nanotubes in incandescent lamps, replacing a tungsten filament in a lightbulb with a carbon nanotube one. > > Nanomechanical computer storage devices using nanotubes are currently in the prototype stages. Both high speed non-volatile memory which can be used to replace nearly all solid state memory in computers today, and high density storage that may replace hard drives, are being developed. Major limiting factors in the development of nanotubes include their cost and difficulties in orienting the nanotubes, which tend to tangle because of their length. > > As of 2003, nanotubes cost upwards from 20 euro per gram to 1000 euro per gram, depending on purity, composition (single-wall, double-wall, multi-wall) and other characteristics. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [January 6, 2005, 2:11am UTC](https://boards.straightdope.com/t/is-there-any-economic-potential-in-space-exploration-colonization/282778/29 "2005-01-06T02:11:39Z")
**Shalmanese** said: > [@](#): > > When you say 6 billion tons, thats like saying theres more gold in the ocean here on earth than has ever been mined. The problem is if it’s so sparsely distributed that it would almost certainly be unprofitable to mine. There would have to almost certainly be some sort of deus ex machina of the nanotechnology or free nuclear fusion kind to even posit doing things like extracting hydrogen from regolith. And, IMHO, most of the hype surrounding both of the aformentioned technologies is precisely FROM future geeks who need something to justify schemes like extracting hydrogen from regolith. Of course it depends on the form, but it seems clear that hydrogen and oxygen exists on the moon in at least three forms: 1. As cometary residue. This stuff may be eminently mineable. For a while, NASA thought that it might even exist in the form of massive sheets of ice, just waiting to be chipped apart and hauled away. That doesn’t look likely, but it does seem likely from the water signatures lunar prospector and Clementine picked up that it at least exists as ice-rich soil where grains of ice are distributed through the soil in fairly high concentration. After all, the water was detected from orbit, so we’re not talking microscopic amounts. 2. In the case of oxygen, bound up in silicates and oxides in the regolith. How hard this is to extract is an open question for me, because I don’t know enough about chemistry. 3. In the case of hydrogen, it exists in the regolith as free molecules from the solar wind, from what I understand. So there would be no chemical process required to liberate it - just perhaps some heating, or churning, or whatever it takes to release it. The ‘gold from water’ analogy doesn’t really hold for a simple reason: Gold is relatively inexpensive compared to the value of water on the moon. We CAN recover gold from seawater, we just can’t do it for less than what the gold would be worth, so we don’t. But if gold were $5000 an ounce instead of $300, I’ll bet we’d find a way. In any event, we really don’t know what kind of effort we’re looking at right now. We need to go there and explore. Good thing that that’s exactly what NASA is gearing up to do. If extensive water deposits are discovered, it’ll be a huge boost to the prospects of living in space anywhere. [Previous page](https://boards.straightdope.com/t/is-there-any-economic-potential-in-space-exploration-colonization/282778.md?page=1)