Building a Moon Base: Part 4 – Infrastructure and Transportation

In this exciting but challenging period of space exploration, the time is fast approaching for serious design concepts for the first habitats that will be built on the lunar landscape. In previous articles, we have examined the hazards associated with such an endeavour, we have looked at the structures available to us, we have even detailed a particular hangar-like structure that might use locally mined materials. Now, we look into the possible infrastructure elements that will be needed to support a viable colony on the Moon. Florian Ruess, a structural engineer who is working on the future of habitats in extreme environments, also took some time with the Universe Today to give his opinions on mankind’s future on lunar soil…

Imagine trying to build a structure on the surface of the Moon. Two of the biggest obstacles the first lunar settlers will come across are the very low gravity and the fine dust causing all sorts of construction issues. Although it seems likely that the first habitats will be built by automated processes before mankind even sets foot on the moon, fabrication of a settlement infrastructure will be of a primary concern to engineers so construction can be made as efficient as possible.

The basic, but optimal shape for a lunar habitat module linked with other modules (image courtesy of Florian Ruess)

Infrastructure will be one of the most important factors concerning mission planners. How will building materials be fabricated? How will material be supplied to construction workers? How will precious water and food be supplied to the fledgling lunar colony? Can supply vehicles go from A to B with little effort?

Historic examples of the effectiveness of an efficient transportation infrastructure can be seen in the coalescence of cities around rivers (traditionally the quickest way to transport people and material around a country). Canals were instrumental in bringing cities to life during the Industrial Revolution in the UK in the late 18th century. As railway lines linked the East and West of North America in the last half of the 19th century, acceleration in population growth was experienced by people uprooting and “homesteading” the new, accessible farm lands. Over the last 50 years, the “Southern California freeway effect” is responsible for the proliferation of gas stations, restaurants, shops, followed by residential areas for workers – eventually whole towns and cities are based around the ease of access for transportation.

Concepts of a lunar infrastructure (credit: NASA)

Future manned colonization of the Moon and Mars will most likely be based on a similar principal; the success of a lunar settlement will heavily depend on the efficiency of the transport structure.

It seems likely that most transportation around the Moon will depend on wheeled methods, following from terrestrial vehicles and tried and tested “Moon buggies” from the Apollo missions in the 1960’s and 70’s. There are some significant drawbacks however. Addressing this issue, Florian Ruess, structural engineer and collaborator with Haym Benaroya (whose publication this article is based) points out some problems with this mode of transport:

For any mission there will always be the need for individual transportation and the obvious solution is some wheeled vehicle. But there are a couple of serious issues with this solution:

  • Reduced traction. 1/6 gravity and the lunar soil make traction a problem just like [the Mars Exploration Rovers] Spirit and Opportunity on Mars one can get stuck easily or need to much power to get around.
  • Dust. Apollo experience shows that a lot of dust is levitated by wheeled vehicles. This dust is hazardous to machines and humans when breathed in.”

– Florian Ruess (private communication)

So travelling around in a modified “dune buggy” might not be the answer for an established Moon base, some form of road infrastructure would be needed if wheeled transportation is used.

Neil Armstrong's footprint in the lunar regolith (credit: NASA)

Disturbing dust on the lunar surface is far from being a minor problem. From NASA’s experience with the Apollo missions, by far the biggest contributor to dust generation was the take off and landing of lunar modules. 50% of the regolith is smaller than fine sand and approximately 20% is smaller than the “dusty” 0.02mm that preserved the Neil Armstrong’s first boot prints. It is this very fine component of the regolith that can cause a host of mechanical and health problems:

  1. Vision impairment
  2. Incorrect instrument readings
  3. Dust coating
  4. Loss of traction
  5. Clogging of mechanisms
  6. Abrasion
  7. Thermal control problems
  8. Seal failures
  9. Inhalation

It therefore seems obvious that dust creation should be kept to the bare minimum as this factor could be a severe hindrance to the infrastructure of the settlement.

Roads are would be the perfect answer to the new lunar colony. They would provide wheeled vehicles with the much needed traction (thus having a knock-on effect with the fuel efficiency of the vehicle) and may significantly reduce the amount of dust suspension, especially if the road surface is raised above the surrounding regolith. Roads, however, have their drawbacks. They are enormously costly and may be very difficult to build. Fusing regolith to form a tough surface may be an answer, but as pointed out by Ruess, “…this requires enormous energies, which cannot be provided by solar power alone.” So an alternate form of energy would be required to perform such a construction.

(a) Basic Roman road design features, (b) 2000 road design, (c) model of force distribution (credit: Haym Benaroya, Leonhard Bernold)

Although road construction would be highly desirable, it may not be possible, at least in the early stages of lunar settlement development. One emerging development in alternative space transportation is the vertical take-off and landing method, but as previously stated, rocket-powered take-off and landing produces vast amounts of dust. But should there be multiple bases on the Moon, this might be a possibility, “…a lot of people recommend different solutions for routes that will be used frequently like getting from the landing pad to the settlement or from one settlement to the next,” Ruess adds.

Lunar habitat with a cable-based transportation infrastructure (credit: H. Benaroya, L. Bernold)

Another solution is an established form of transportation. Totally avoiding contact with the surface, thus cutting down on dust and avoiding obstacles, a lunar cable car might be a viable possibility. It seems likely that such a cable car transportation network would be highly effective. “Very large spans will be possible on the Moon and therefore infrastructure cost not exorbitant,” Ruess points out. This possibility is being seriously considered by lunar settlement planners.

Looking back on the previous articles in the series, Florian Ruess comments on whether lunar bases can be mobile and points out some of the severe difficulties facing settlement planners if locally mined materials are to be used:

I am not a big fan of mobile bases. Such a system that includes power generation, communications and especially long-term meteoroid and radiation protection does not seem feasible to me. But the wheeled vehicles could be pressurized designs capable of serving several-day-long science missions. This would be a good solution to expand the capabilities of a permanent base.

Local materials are a crucial yet difficult issue. My research so far has shown that only after a certain presence has been established and experience with lunar issues and materials has been gained we would be in a position to dare and build habitats from local materials. Certainly not before man sets foot on the Moon. And please forget about the much-cited lunar concrete! There are so many showstoppers for this imaginary material that I don’t even want to start mentioning them. The only early local material application I see is meteoroid and radiation protection using regolith as shielding material.

“Building a Moon Base” is based on research by Haym Benaroya and Leonhard Bernold (“Engineering of lunar bases“)

Plus an exclusive interview with Florian Ruess, extreme habitat structural engineer and founder of Habitats for Extreme Environments – HE2

-Florian Ruess, private communication.

Many thanks to Florian Ruess for his time in contributing to this article. For further information about his work and extreme environment habitat designs, visit his website at:

For more information about the future of lunar settlement, check out the Moon Society and the collaborative resource, Lunarpedia.

45 Replies to “Building a Moon Base: Part 4 – Infrastructure and Transportation”

  1. I wonder if Lava tubes would have retained any of the gas that may have hung around in the primordial atmosphere of the moon. Such places wouldn’t have the solar wind stripping away gas and the gravity of the moon might draw said gas down into the deeper parts of the lava tube.

    In any case I would say that some sort of inflatable designed to be inserted into an existing lava tube would be our best bet for a quick set up. The membrane might be made to expand and fill the entire volume of space provided by the lava tube and the Tube would provide structure and protection to the membrane.

    As far as the issue of transportation I think, as retarded as it might sound, jumping seems like a reasonable idea. With considerably less gravity to fight and the issue of Dust arising from wheeled or pressurized gas transportation, some form of mechanical jumping system that minimized the amount of contact a person had with a surface might work, maybe something like Pogo Shoes.

    Heck with the limited gravity, it might not be infeasible to contrive some form of magnetic superconducting hovercraft. A pair of electrically charged cables, laid side by side along the lunar surface could be anchored at the ends and provide a fairly easy to assemble road for a small transport using magnetic repulsion.

  2. Ok, so here’s an idea that springs to mind. Given that there is no wind to blow the dust around, why not create a dust-free “clean zone” (of perhaps a couple of hundred yards) around the base before you establish it? Sure, that’s a lot of dust, but It’s easy to move the dust, so why not spend some time and money blowing it away from the site before building the base? If it takes an extra few months, that’s not a big deal. (I’m sure Hoover or Dyson would be happy to work on developing the technology 🙂 )

    Once the dust has been moved, it won’t ever blow back under natural conditions. The only thing you have to worry about then would be the dust brought in from excursions away from the base. That could be dealt with by establishing a cleaning facility at the edge of the “clean zone” that would remove the majority of the dust from the incoming vehicle or space suit. And the base’s spaceport would probably be far enough away (for safety reasons) not to cause the dust to be blown back in.

    Sure, it’s probably impossible to get rid of all the dust, but if the colonists only had to deal with a tiny percentage of what was there initially, a “clean zone” system would save a lot of time, money, and resources over the lifetime of the colony.

  3. I guess that my first question is “Why?”

    What purpose is there in returning to the Moon that can’t be solved more easily by building an enhanced space station in Earth orbit?

  4. I like the dust free-zone of a couple hundred yards radius, Tacitus. Seriously, perhaps a shaped-charge explosion of a nuclear device to fuse it all into glass or sand? A designed nuke whose hard rads will die off quickly.

  5. Regolith Ice Cube Paving Stones. I recall that there are enough materials on the lunar surface to create water. So why not make a slurry with regolith and water? When poured into molds then exposed to space to freeze the resulting ice bricks would make excellent paving stones – or habitat building blocks for that matter.

  6. I imagine this is going to be really expensive at first but as time goes on, it will probably be self-sustaining and maybe even profitable in monetary terms.

  7. When I agree that it would be better in the long run to build cities in orbit instead of back in a gravity well with no air to make it worthwhile, you want a lunar base to mine material to build those cities in orbit. Using solar power, you can mine stuff that would be much easier to get than from the Earth. And you can build solar powered rail guns to launch the stuff to it’s destination. The late great Gerald O’Neil did much study on this for NASA.

  8. A functional life sustaining base on the moon? Interesting thought. I wonder how many governments will be required to fund this project?

  9. Frank is correct about mankind’s engineering prowess. We’ll eventually get to the moon. However, I suspect it will take several billions of dollars and generations before any nation can set-up permanent house keeping on the moon. I’m basing my comments on America’s current plans to go back to the moon. To go there in the next decade or two (why so long?), spend a few days on the surface and return is a technical no-brainer. To develop a means to stay permanently, in the interest of pure science, will most likely be found to be economically impossible. Unless, of course, there will be some clear-cut permanent military interest, than our elected leaders will throw a high percent of our gross national fire-power at the project and presto, there will be a permanent base. You know, similar to the green zone in Iraq.

  10. I think that a cable cart is a good idea but i also think some sort of hover craft using magnets or something woul be a good idea.

  11. Lunar bases will happen because of elegant solutions by engineers and technical experts. Everyone conveniently forgets how enormously expensive and dangerous it is to put anything into space. Throw in a lunar landing/takeoff and you’ve more than doubled the risk and expense. Throw in human beings and everything it takes to keep them alive in such an environment and it is a daunting engineering feat unlike anything in human history

    Every gram of mass lofted upwards is precious. When people talk of pogo boots, nukes and maglev, well, my advice is put down the sci-fi books, stop watching Star Trek and use that prodigous imagination to think of realistic solutions rather than juvenile musings that are insulting to the real engineers that have to solve the real problems within the framework of the reality that exists today.

  12. Seriously, perhaps a shaped-charge explosion of a nuclear device to fuse it all into glass or sand? A designed nuke whose hard rads will die off quickly.

    Heh. I’m guessing that would be what they would call the sledgehammer approach! 🙂

    Not saying it wouldn’t work, but given the public queasiness over launching very safe plutonium power packs into space, I suspect the idea of launching a less safe nuclear weapon to the moon would be a tough sales job to a nuclear averse public.

  13. When I agree that it would be better in the long run to build cities in orbit instead of back in a gravity well with no air to make it worthwhile, you want a lunar base to mine material to build those cities in orbit.

    For one, the Moon is a far better place to conduct astronomy than in orbit around the Earth. If we are going to explore the solar systems around us (i.e. exoplanets) then the only practical way to do it in the forseeable future will be through the end of a telescope. A permanently dark crater near one of the Moon’s poles is just about the idea place in which to put a large telescope — all the advantages of no atmosphere without all the problems of being in NEO.

    There will be room for both orbital habitats and lunar bases in our future. Both have advantages and disadvantages (many of which we probably haven’t even guessed at yet!).

  14. Throw in a lunar landing/takeoff and you’ve more than doubled the risk and expense.

    It’s a lot easier to land and take off from the Moon than it is Earth. So, you’re only doubling the risk if you take into account that we have to get to the Moon as well as land there, and once out of Earth orbit, you’re bail out options are greatly reduced. (Mind you Apollo 13 managed to cope, and that was decades ago!).

    But my bet is that colonization won’t be widespread until we solve the issue of getting off Earth in a safer and cheaper fashion. That’s why I think the Space Elevator idea has legs — assuming we can solve the materials science needed, which is probably the biggest hurdle. Even if we can’t do manned launches (because of radiation issues) the fact that we will be able to launch bulky cargo into space cheaply and efficiently will greatly enhance our ability to colonize the Moon and Mars. Not to mention that they are both places where a Space Elevator could be deployed also!

  15. honestly this sounds amazing, but whose to say when we go to far? Say we do finaly get a life sustaining area on the moon, whats next? will we keep adding to it? Untill one day the moon is covered in things? How far is to far?

  16. Great conversations from a provocative and interesting ariticle. While reading the ariticle, I wondered if anyone would think of the Earth Space Elevator research, which would work 6 times as eloquently on the moon. There would be little need for landing/take-off ports, just use orbital UPS Elevator freight.

    Considering the areas with meaningful mineral deposits will probably be just as far apart as our investigational landings will be, roads would seem impractical.

    Another item wasn’t mentioned, albeit Mr. Florian Ruess commented in the same vein – history. I was thinking go further back into history and find a cave, or blast one out with that aforementioned nuclear shape charge. I don’t see why not since a nuclear power plant seems the logical choice, eventually.

    Caves saved our butts on Earth and allowed us to dominate an entire planet. Once we find/create the cave, seal off the front and develop human habitat. After all, habitat will need humidifying and might be part of the solution for dust. Either we sweep the cave out or the construction process alone will compress the ever so lightly moistened dust.

    Mountains and caves go hand-in-hand here. There are some whopper lunar mountains.

  17. honestly this sounds amazing, but whose to say when we go to far? Say we do finaly get a life sustaining area on the moon, whats next? will we keep adding to it? Untill one day the moon is covered in things? How far is too far?

    I dunno, how far is far enough?

    Seriously, though, assuming we continue to thrive as a species, who knows what will happen in the long term (by 2500, by 3000, etc). If we find the Moon profitable, I would expect us to exploit it to the fullest. If mass interstellar migration remains impractical, then the Moon will likely be the second most desirable chunk of real estate after the Earth until Mars can be terraformed. (The Moon wins over Mars in the meantime because of its proximity to Earth).

    So, if in the distant future we want to live somewhere with our feet firmly planted on solid ground (i.e. not in space habitats) then the options are limited. Hence the Moon may have millions of people living on it one day. Too many? Again, I dunno.

  18. Tacitus: dust free zone: excellent. Aren’t the dark areas of the moon (the seas) areas of more recent lava such that they might not even be deep in dust? Nice bedrock foundations? I’ll go out with my leaf blower, come out with the iced tea.
    Caitlin: The moon is not an ecosystem, environment yes, but there’s no life. Nothing to wreck or destroy. The stark beauty will remain. We’ll never cover the surface, too few resources. I’d rather science and population take us there than into the last recesses of our Earth.
    Frank: you got yours from Silver Thread, he said it better than I could. Insulting others for insulting engineers … clever.
    Anyone: Is the atmosphere on the moon dense enough to suspend dust? Even just over the surface? Or does it just fall back within 2 or 3 seconds?

  19. i think that it is the lack of gravity that allows the dust to stay suspended longer.
    I agree that the base should be uilt underground, and i understant that it will be expensive, time consuming and power intensive. However, i think that we will minimize the dust problem by building underground. additionally, the layer of surface overhead would provide protection rom meteors and radiation without having to build much of anything. if we centralized the base around a vertical lava tube that could be domed over, we could drill into the sides to create ledges and tunnles for habitation and storage. even though i know we are trying to stay away from science fiction, it would be similar to the city of Zion in the movie The Matrix. subways i think would be a dust free form of transportation, or if that is too expensive, raised monorails would be cheaper and less power hungry than the magnet train and the lack of gravity would be a prolem for the suspension cable cars whereas the monorail is fixd to the track so friction wont be a problm either. we could take advantade of the lack of gravity with the landing craft. if we had ships with vertical take off it would be pretty easy to land the ship on a platform just inside the lava tube considering the tube is wide enough, which eliminated the landing strip and the dust contact. the ships probably would not be earth worthy, so a ferry system would have to be established where a ship brings people and cargo from earth to the lunar ships that take them to the moon. or istead of landing ships, cargo could pass through an air lock and lifted by the elevater concept. (personaly i think that the elevator on earth is too farfetched, but seems way more feasable on the moon). finally, solar farms are much more feasale on the moon since half is always in the sun and there is no atmosphere to dull the light. plus underground, we wont mess up the landscape…

  20. Engineers only think “inside” the box. That’s the problem with engineers. Man’s accomplishments have been in spite of engineers, not because of them.

  21. Show me one new technology, Frank, where engineers weren’t dragged kicking and screaming to a successful result. That’s why engineers don’t run really successful companies, They have to be controlled and prodded every step of the way.

  22. Hey! All of you guys. Stop and think. Man most likely will never establish a permanent self-sustaining base on the moon. There is no sensible return on investment. Not even for military advantage. Scientific curosity isn’t enough to justify the mind-bending expense and technological challenges involved. Who, in any government is going to lay his or her credibility on line proposing something as useless to the common man as a moon base? So, all you dreamers keep on dreaming, it’s good mental excercise. If you make it to Washington, save face, stay reposed.

  23. From Andrew:

    subways i think would be a dust free form of transportation, or if that is too expensive, raised monorails would be cheaper and less power hungry than the magnet train and the lack of gravity would be a prolem for the suspension cable cars whereas the monorail is fixd to the track so friction wont be a problm either.

    That’s actually a great idea Andrew! I was thinking about something similar. Why deal with the dust problem when it may be easier to simply create pressurized, underground subways instead?

    Oh yeah, don’t mind the angry people. They are just here to remind us all on how superior they are than us. 😉

  24. the problem with the subways is that is is signifigantly more expensive and time consuming to build that the monorail because you have to drill through the rock and the less gravity you have the harder it is to do because you need large amounts of friction with the tunnel walls to drill. pressurizing the entire tunnel seems kind of a waste of precious gasses (no offence), seeing as we could just pressurize the cars and/ or have the train pass through an air lock. i still think that avertical takeoff craft is an even better idea to deal with the dust than a runway, and plus with the lack of gravity, a runway will be harder to land on because you would need more distance to stop… mabye, right?

  25. just out of curiosity, how long would the lag be if there was a moon-to-satelite-to-satelite-to-earth internet connection?

  26. Frank, my hat is off to you. Despite my sarcastic rejoinders you provided a respectable and level headed riposte. You have my respect.

    I agree that to spend your life fantasizing without ever making an effort to apply your ideas in some useful way is an exercise in futility. I maintain that science fiction is not without some redemptive merits but I also agree that to waste hours fixating on Video Games and Television does absolutely nothing for society. Take that inspiration and put it to use.

    In any case I enjoyed the discussion, I apologize to the audience, whom I can only assume has read my tirades with a few long suffering shakes of the head and as for the Challenge Extended, I suppose at some point I may indeed need to attend College, for now I will continue earning a living doing what I enjoy.

  27. Frank,

    That’s quite a thorough response. Although I don’t agree with everything you wrote, you do make some valid points.
    I won’t dwell further into this because I don’t see that much would come from it. There are also many more articles that I would like to read and possibly respond to with my own suggestions/opinions. 🙂
    See you out there………………

  28. haha. dont we essentially have “photon torpedoes”? the best example i can think of besides fireworks are flares and flashbangs. they dont destroy anything and wern’t inspired by star trek, but i thought the connection was amusing. : )

  29. I am a studant o correct me if i’m wrong but I se a way to create electricity. Glare from the sun can be reflected onto a metal (or other fast heating material) pipe filled with water or oil. Once the substanc is boiling it can be mixed with a colder substance to create steam. The steam would turn a turbine wich would create electricity. Problems would be supplying the substances needed and low gravity. I read an article on yahoo about this being done on an earth powerplant. Once more I am a student and this might not be ale to work or be produced in space.

  30. Sami,

    You’re making reference to the solar furnace. Designs vary but the one in Nevada uses an enormous field of concave mirrors focused on a sodium filled ‘furnace’ that does indeed heat it to a liquid state. The sodium is in a closed loop and transfers its heat to water for steam.

    My guess is that this would be the most practical power plant for a lunar station. It would take up a lot of space but not as much as a solar cell array. The technology is established and radiation-free but still quite huge and lunky to transport. It would, however, generate mega watts of power. Its safety and useablity in a lunar environment is an unknown.

    Keep in mind that the first moon base, more than likely, will be inside Shackleton Crater at the lunar south pole. It has permanent shadows that shield parts of the floor from any solar radiation and light. Being at the south pole, however, provides about the only location that will get constant sunlight above the crater floor for the entire 28 day lunar cycle. At the equater all the way down almost to the south or north pole there are 14 days of darkness. This is an enormous challenge because you just can’t put your laboratory or living facilities into hibernation for 14 days.

    If current plans work out, the habitat will be in the permanent shadow on the floor of Shackleton. This protects the outpost from the intense solar radiation. It doesn’t do a thing for the rain of meteorites so using lunar regolith to cover the habitats will be the most practical solution.

    Now we’re back to electric vehicles, such as a lunar front end loader, to scoop up regolith and deposit it on the top of the habitats. Ignoring the huge weight that must be launched and landed on the lunar surface, you’ll need a lot of power to run such vehicles. Your solar furnace, or a variation would be, for all it’s weight and complexity and assuming it works in the lunar environment, the most practical, simplest and efficient power source.

    Having said that, it will have to be located on the permanently illuminated rim of Shackleton with a power feed line going over the edge, down the slope to the outpost at the bottom.

    If the images I’ve seen of Shackleton are accurate, that’s a long way down. For research access to the rim and for maintenance of the furnace there will have to be a lift of some sort because no one will be able to climb the slope. So now we’re into the cable car noted in the article. This could double as a power cable support. Now we’re into the problem of building the towers on a slope that you can’t walk up or down on. It’s a frustrating engineering problem.

    Another issue in the article is getting around on the surface. Some posters have mentioned using rockets to liftoff and transit horizontally setting down wherever you need to go. That’s a very dangerous and costly method that should be reserved only for return flights home. Any combustion of fuels for such a purpose expends a very precious resource that you won’t have a lot of. Any time you fire up an engine you risk explosion. It has to work perfectly every time… one burp and you crash on the surface.

    In my years working at a nuclear plant I had the priviledge of working with one of the former engineers for Grumman who’s team helped develop the ascent engine for the LM with the Bell Aerospace subcontractor. He related the enormous difficulties of designing a lightweight but powerful engine that had to work the first time in a vacuum. The rocket scientist’s axiom of “Simplicate and add lightness” was in full force during the development of the engine. The final engine design was exquisite but it was designed for a one-time use.

    It was a hypergolic engine design where all you had to do was open valves and let the liquids come in contact with each other in the combustion chamber and you had thrust. As simple as that sounds, the oxidizer had to enter the combustion chamber a split second before the fuel. If the fuel got there first there was the possibility of the engine exploding when the oxidizer entered.

    The engines used a fuel of Aerozine 50 ( half-and-half mixture of hydrazine and unsymmetrical dimethyl hydrazine) and nitrogen tetroxide as the oxidizer. Both very nasty if you come in contact with it and explosively deadly if these two liquids made contact outside of the combustion chamber. You couldn’t afford leaks in your tanks or degraded seals in this caustic environment in your valves or out-of-sequence implementation. The consequences would be catastrophic. A crash on the surface, in all likelyhood, would result in a large explosion and some very dead human beings.

    Always keep in mind that any rocket firing anywhere, especially on the moon, even to just to hop a mile or so “over there” is a major technical feat and is never taken lightly. The chance of failure for such casual use is too high to risk it as a method of lunar transportation except for the return ride home.

    Also, putting aside the explosive nature of the engines, because of density differences in the fuel and oxidizer, the tanks empty at different rates affecting the center of gravity. The LM’s slowly rocked side-to-side on ascent as the RCS fired to bring the vehicle back to vertical. This would preclude using it to lift any kind of usable mass for any kind of lift as in a crane replacement operation.

    So, what is the solution to transport on the surface? I really don’t know. Lunar rovers, for all their drawbacks seem to be the best solution right now.

    I don’t believe it’s impossible to colonize the moon but it ain’t gonna be easy. As the article above noted, dust is a difficult and perplexing problem. You can’t bring it into the habitat or you’ll be breathing it and, like it or not, it will manage to get into every piece of hardware that is exposed to it.

    I think the idea of building a ‘roadway’ is technically prohibitive. Assuming you could do it, you’d only have a road between point A and point B. It’s a safe bet there’s going to be something interesting to go look at over on point C, D, E, F etc. It’s simply impractical to build a road everywhere you want to walk or drive. I think the solution for the exposed vehicles is better design on seals and rigorous maintenance.

    For the space-suited lunarnaut I think a mylar-type coverall going from the top of the boot sole to the helmet and down the arms to the gloves and secured to seal off the interior of the coverall would provide several things for the lunarnaut. The smooth metalized surface would provide the least surface area for dust to adhere. It would provide another layer of solar radiation protection because of its reflective surface. It would also provide a possible dust removal method that’s simple and effective.

    Upon entering the airlock and as the air pressure returns, the dust-covered lunarnaut would connect low-voltage electrodes to the mylar-like coveralls and induce a current that alternates between negative and positive. At the same time, the lunarnaut would stand in a high-tech ‘boot polisher’ that would scrub the soles and suck the dust down to a hepafilter to be trapped and contained. At the same time as the air pressure in the airlock builds an air shower, not unlike what cleanroom technicians use prior to entering the cleanroon, would blast the exterior of the mylar-like coveralls. As the voltage goes back and forth the charge on the dust would cause it to be repelled as the polarity flips back and forth. The airshower would blow the dust away from the lunarnauts and be sucked toward a hepafilter to be trapped. A minute or so of this and the airlock area and the lunarnauts should be dust-free and ready to get out of their moonsuits.

    I don’t know if it would work but it’s simple and the technology already exists.



  31. I am afraid I am unaware of even a single show stopper to lunar concrete. After first reading this article, I tried an internet search on the subject, and the first 30 or so articles I found seemed to say the concept was feasible. Could somebody direct me to where I can find any of these?


    You commented earlier about how massive a nuclear reactor would be, and seemed to refer to land-based reactor designs. Are you familiar with the design of reactors used in nuclear submarines? Most space reactor proposals are scaled down versions of those, not reactors used to supply power to the main grid of many cities.

    About CG motion on the LM ascent vehicle, I’m not sure I can agree with what you said, unless you mean vertically toward the engine. The two propellants (N2O4 and Aerozene-50) have noticeably different densities, and in any hypergolic engine are not used in the same proportion. From what I have heard, the earliest concepts had two N204 (oxidizer) tanks opposite each other, and two fuel tanks opposite each other perpendicular to the first two. The two tank design worked because the two tanks did not need to be equidistant from the engine as would be necessary in an aerodynamic vehicle. While the lighter fuel tank was loosing mass more slowly than the heavier oxidizer tank, it was also the further away of the two, so the overall affect (side to side) on the CG was to keep it still. Vertically, fuel was always forced to the bottom of the tanks by the acceleration of the vehicle, so as fuel was used, the CG would move down… but have very little affect on the vehicle’s CG. This is also a very good thing, as the RCS thrusters had only about 1/40 th the thrust of the main engine, and that engine was non-vectorable, so any major change side to side in the CG would lead to the vehicle loosing control on the way up. Those RCS thrusters may have been strong compared to what is used on satellites, but not quite that strong.

    On a side note, about the earlier mention of Star Trek. We do have at least two technologies that were inspired by that show: sliding doors (straight off the set, I’ve heard the production crew received calls from engineers on how they did it, the response was stage crews holding ropes behind the set) and cellphones (remember those “communicators” from the original series… ?)


  32. Learn something new every day…

    I actually thought the ascent stage RCS used the same tanks with/as the main engine. Thanks for that link.

    On the subject of lunar power: I agree that a solar furnace may be one of the best options for powering a lunar base. However for nuclear power, I usually assumed that all that would leave earth would be the reactor core and some sort of heat engine. Just land the thing a few kilometers away from the base, perhaps on the other side of a hill or mountain and use that mass (and distance) as rad shielding.

    I’ve often heard estimates about small reactors weighing less than a tonne, of course with outputs usually less than 100kw, but still easily under the capacity of the Atlas V and Delta IV vehicles. Not quite on the same scale as what you work with. What do you think the output of a reactor could be, if the shielding is the moon itself, of a reactor weighing somewhere around 3 tonnes or so? No need to rely on NASA finishing project constellation or anything, I only really care about what could be done today or with programs unlikely to be canceled.

    If you ask me about the cost of Aries I and V, tho, I’d say closer to $800 million and $2B, respectively.

    Perhaps I’ve heard too many horror stories about Aries I, Orion, and Constellation in general, tho.

  33. Michael P.

    For any truly significant electrical output, you’re stuck with a steam cycle (or some variant) just like the solar furnace for power generation. Nuclear reactors achieve their temperatures by fissioning the nuclear pile. This requires a cooling loop to keep the reactor from overheating and melting the core; the classic China syndrome we hear so much about. This cooling loop is run through steam generators that transfer the heat to the steam cycle water. I just don’t see, even absent any shielding, a way to get a reactor that would be small enough for launch and still generate enough power for a respectable moon base. I would think that if NASA goes for it (a lunar base) they’d want to have more than enough electrical capacity for any future expansion. I’d sure rather have too much than not enough. But, as always, there’s that trade-off — the bigger the reactor the more power you’ve got but the more weight you have to throw up at the moon. It’s a maddening problem.

    And still, the shielding is ultimately going to be needed. While refueling can be virtually eliminated with a nuclear sub type reactor using highly enriched U-235, basically bomb grade U-235 (25-30 years per core) maintenance would be impossible without shielding. I can’t imagine going to all of the expense and labor of putting a reactor on the moon only to abandon it in place when a minor maintenance issue renders it unusable because it can’t be approached. Fissioning nuclear reactors, I’m afraid, are just too problematic.

    And, on a side note, what would you have to deal with just to launch the reactor? I still remember the stink that was raised when Cassini was launched because it had an RTG for power. Environmentalists even raised hell on the Earth fly-by that Cassini did to gain speed for its outbound flight. I can’t imagine the uproar if an actual nuclear reactor pile was launched.

    I found this on Wikipedia. It’s info about the only full-fledged US nuclear reactor to fly in space. It used thermocouples to generate electricity and its output was only 500 watts

    NASA seems to be showing some interest in Stirling radioisotope generators which seem to generate 4 times as much power as an RTG. You’re still looking at only 100-120 watts of power, not a lot for a moon base.

    I had a discussion today at the launch of the ICO-G1 Communication satellite (launch pics here: and the consensus is that any nuclear reactor is too much nuclear reactor. These guys weren’t the planners and engineers but they are very much up on the current state of the art, such as it is.

    I’m going to start asking my contacts at KSC who the lead engineer for the power generation design group is and get his/her thoughts. I’m getting very curious about this. Stay tuned.



  34. While I’m not sure I would put the same overcapacity into the system as you are talking about, that is a valid point. Same goes for maintainability.

    And yes, I do agree solar thermal would be an excellent system for use on the Moon. It does have one major drawback compared to nuclear: the 14 day lunar night. Personally, I think the best solution to it is a sort of hybrid system, with solar thermal providing main power during the day (hopefully most power-intensive activities on the base could be done then), and some minimal suplimentary or keep-alive power during the night span. This is the main use I see for nuclear reactors, although there are many non-nuclear methods for storing energy available for slightly higher mass.

    If I recall correctly, the Artemis society’s Reference mission would have provided keep-alive power for the early base’s electrical systems (etc.) using residual hydrogen and oxygen gas from the decent stage’s propellant tanks, for use in fuel cells. From the numbers I saw, they could look forward to perhaps 300-400W of power during the night span. How about replacing that system (which would involve designing the propellant tanks to double as pressure vessels) with a sterling-cycle radioisotope generator? Those are relatively compact systems, so a base crew could probably just pile up some dirt around a box with the generator inside (allowing some method for heat to be radiated away, of course) to provide rad shielding While this isn’t exactly a “light up Las Vegas” type of system, it should work for an early lunar base.

    Now there are issues with that plan if a non-governmental agency (or rich visionary individual…) wanted to use plutonium-237… But from a technical standpoint it seems plausible to me.

    -Michael P.

  35. Michael P.

    NASA seems to have its heart set on Shackleton Crater at the south pole. The crater’s rim is in permanent sunlight. A rotating parabolic mirror would keep the sunlight focused on the furnace virtually forever. I think that would solve the night issue.

    The only problem I see with the base in the crater in the permanent shadows and the power plant up on the rim is cabling the power down the slope. I’m a little uneasy laying a megawatt cable on the regolith.

    High voltage is very tricky. There is a powerful magnetic field that surrounds a high-tension wire. One weak point in the insulation/shielding and, just like lightning, a passing magnetic field no stronger than golf club during a swing or an astronaut in a space suit and a huge arc will jump to ground through the disturbing magnetic field. I’ve seen birds get killed flying close to a high voltage wire where they disturbed the magnetic field of the flowing electricity and draw a lightning-like arc to their bodies. Smoke and feathers were all that was left.

    This isn’t a fatal flaw to the idea but it must be carefully considered if an exposed cable is used.

    My guess is that towers to suspend the cables are out of the question from a purely construction logistics standpoint.



  36. Frank,

    Though it is hard to disagree with some of your points, it pays to do your homework when you criticize others. Those kids who are playing the games are going to be the ones doing whatever engineering is done in the next generation. In my generation(I’m 60), there were bunches of PhD physicists and engineers pumping gas, so many people chose other jobs. Once the Moon program wound down, many of those who were so committed to such work were forced to seek other employment. If we want competent engineers, we need to offer them consistent opportunity for employment after we educate them. Right now, many degreed and experienced U.S. engineers and physicists cannot find jobs in the face of H1-B immigrants and the shipping of the majority of manufacturing and even development jobs overseas. If we want to rebuild our base, we have to offer them a way to make a living. In addition, those who do the usual 5 year programs for even such bachelor’s programs, end up owing tons of money from student loans, which they have a hard time repaying. Now, if we were to offer them government service to repay those loans, more might be willing to take the risk.

    But let us get back to the subject. Many lava tubes are found in the horizontal/slightly slanted mode over fairly long runs, so that problem is not likely to be quite the issue that you have portrayed. Now, whether such could be found at the preferred location is another issue entirely. It is really not that difficult to discern some of these things. A fairly powerful orbital radar can map such subsurface features fairly easily, and robots can prospect to confirm results. These are not missions that require a huge commitment, but even these have not been done, so the process seems more dog and pony show than realistic mission. I don’t believe that the current administration has or ever had any realistic plans to actually do this mission, only to appear interested in “space” to deflect those who actually are interested and see the need.

    As far as power sources, the biggest problem is not heat creation, but heat rejection in a vacuum. Any closed system has to have a fairly efficient means to reject heat from the system, to close the cycle, and that is going to be a problem, no matter the method of power production. Solar voltaic has the least problem, but all the others have major issues. Now, with a rim that is permanently exposed to daylight, and a base in permanent shadow, we have the perfect situation for heat gain and heat rejection. We need not necessarily have our facility on the rim or in the base and power on the rim. Very lightweight mirrors on the rim can reflect light down to a power facility far enough down to be largely in the dark or even all the way to the bottom. A stirling engine run by such a unit could produce quite a lot of power in such a situation, certainly enough for intermediate power needs. I do believe that a ton of those nuclear SRG’s and some initial panels would produce more than enough power for initial purposes, while the first solar engine units were set up. It has already been shown that sufficiently accurate solar reflectors can be inflated with hardening foam that is quite light and quite strong, especially in a low gravity, vacuum environment with no “weather” loads. Both trough-style and parabolic reflectors can be created in this manner, and using light and mirrors obviates the need for long, heavy cables that would require maintenance. As for movement in and out of the crater, a very lightweight boom and cable can move astronauts and small to medium equipment up and down without too much strain. For safety, they can ride one of the old type of thruster units should a cable break, though I consider that somewhat overkill. Construction on the Moon will certainly be difficult, so any natural features such as lava tubes or other caves that we can take advantage of should be used. It is a lot easier to seal the inside of such than it is to build and cover any manmade structure. We certainly have materials that should be quite adequate for the task. Also, if we have firm rock, we can blast a hole much easier than we can do any other thing. We also can drill explosively to place the larger explosives.

    As for dust problems, if we found out a way to deal with taconite ore dust after WWII, I suspect that we will manage lunar dust. Certainly, your suggestions or some similar should be pursued, as they seem to have some merit.

    Now, if it were me, I would boost a nuclear engine out to a small asteroid known to contain water, and use that as fuel to go get another one with the rest of the materials needed to build a real orbital habitat around the Earth and then the Moon, making so much of this need for Earth or Moon resources so much less critical.

    Excavating into those would produce a safer orbital habitat than any we can boost, while providing raw materials for almost anything that one can imagine, the most important being space based solar power. Engineering is certainly required for each and every one of those things to be accomplished, but someone, engineer or otherwise, must have the dream, first.

  37. rarchimedes,

    With due respect, I have done my homework and I simply have no faith in anyone who wastes their time (we’re not talking about entertainment here) playing video games. I’m sorry, I disagree with you that these kids will be the next generation of engineers.

    The next generation of engineers is tinkering with things as you read this. Those engineers-to-be are not buried in a bedroom wasting time on blithering nonsense. Our future engineers are inquisitive and rooted in the real world. They don’t fry their brains with this nonsense.

    Your comment about the state of our labor pool of existing physicists and engineers is dead on. The sad state of our high-tech work force is a crime, in my opinion. We need to look seriously at Wall Street and its enablers in Congress to address the evisceration of the R & D and manufacturing base of this amazing country. We went to the Moon. We can do anything. Get the hell out of our way!

    The profiteers of Wall Street have stripped and debauched this country in their headlong pursuit of money, the rest of us be damned. Witness the diminished state of America today if you harbor any doubts about the corrupting influence of ‘capitalism’.

    With the lifetime earnings of our physicists and engineers it would seem that the taxes they pay and the earning power they bring to the economy (never mind the production they are responsible for designing) would justify extensive subsidies for their degrees. As long as you’re not diluting the pool of engineering candidates with H1-B, I don’t believe you can have too many engineers. It’s a demanding discipline and not everyone is up to the academics. It’s self-limiting, so to speak.

    H1-B is the Wall Street ploy to get the cheapest labor to do the intellectual heavy lifting. They then charge the same prices for the finished product and stick that ‘bonus’ profit in their pocket. From their point of view, what’s not to like? From our point of view, how much is enough? When they have everything, then what?

    We need to pull back the military from every base on Earth; charge them with the defense of America out to 200 miles and then redirect those obscene trillions (I can’t fathom billions of dollars and now we’re talking about trillions?… what is wrong here?) to our manned and unmanned interplanetary explorations. We need to aggressively address the issues of renewable, sustainable energy with NO carbon footprint (read: Fusion). We need the infrastructure of the nation rebuilt yesterday. And, (let me pull my bleeding liberal heart out here) there are good Americans who are in desperate need … we will be measured as a people by how we treat the less fortunate of this extraordinary nation.

    Thomas Jefferson once said, “I tremble for my country when I reflect that God is just; that his justice cannot sleep forever.” We need to take that quote to heart. I don’t believe we are doomed but I believe we may have to look into the maw of Hell before we realize what we, in our inattentiveness, have allowed to be done to this magnificent nation.

    As to the lava tubes, since my previous posts I’ve been doing some research. This group funded by NASA has been doing what you’ve suggested by utilizing the data from Clementine and the Lunar Orbiter. According to their research, they’ve identified quite a few lava tubes.

    As you noted, NASA wants to go to the best places for research and development, and lava tubes are where they are. Too, lava tubes are, more than likely, going to present a lot of variability from size to depth to interior configuration. The drilling and digging to access the interiors will be a serious issue. Lava tubes may not lend themselves very well to a standardized habitat design making each one a custom job with all the problems that that would entail. I’m just not sold on the lava tube idea. I believe habitats buried under regolith are the way to go.

    All things considered, I still believe we are limited by what an Ares V can launch. As problematic as a quonset hut design covered with regolith may be, it seems to me to be the best solution at the least cost. The major issue that I see with a buried habitat is getting the regolith on top of the habitats. It would seem some variation of a front-end loader will be necessary to put the regolith on the structures. Once that is done, such a vehicle could do double duty for all of the other heavy-lift projects that will be inevitable over the lifetime of the outpost.

    Here is a design NASA/JPL is currently working on for a vehicle they call ATHLETE.

    While this is hardly the front-end loader I envision, I can see multiple applications for this design that could involve a bucket/dragline of some sort to place the regolith on the habitats.

    Ultimately, everything NASA shoots to the moon will need to be multi-purpose and extensively adaptable. All engineering efforts for the construction and development of the habitat should target minimal construction time, minimal-to-no crew involvement due to the danger of any construction job site and the simplest and most robust design to minimize maintenance. There are only going to be a limited number of flights to the moon. I hate to keep reminding everyone of this but moon shots are very expensive. That all by itself will greatly limit what we can do on the Moon.

    My understanding of NASA’s goals on the Moon is that they plan to target Shackleton initially, quite possibly making it the ‘home’ base. From there, as the technology of building and living on the Moon gets refined, there will be a number of research outposts set up in the non-polar regions. The obvious challenge at these outposts is the 14 days of darkness causing solar power processes to cease.

    The research paper of the group noted above cites their belief that a Stirling engine coupled to a buried heat sink can run through the 2 week lunar night by storing heat in the regolith. NASA is calling for 50 kW of power for the operational needs (that doesn’t seem like much) and this group seems to have a possible solution using the Stirlings. To do research on a lunar-wide basis some method of supplying power through the 2 week lunar night will have to be at the top of the list of ‘things to do’. I’m intrigued with their proposal. I’m going to follow up on it.

    Here is another idea that NASA researchers are proposing that has a novel way to reject waste heat for a concentrated sunlight heat source. No mention is made of 2 weeks of lunar darkness so I can only assume this is a concept for the permanent sunlight on Shackleton’s rim. They’ve done some serious calculations without getting into the specifics of the system.

    Of course, dust will be a major issue for any sunlight concentrating and radiator technology. This paper


    goes into moderate detail about dust transport and the consequences for power system components. Dust, it seems, is going to be THE issue in the design phase of the lunar base as well as the actual application of the various designs.

    I’m not a big fan of the concept of mining asteroids. I think the costs and technology necessary will be prohibitive. The asteroids with water, that might provide fuel for some future mission, only exists in the edge of the asteroid belt that’s closest to Jupiter. Any closer and the Sun heats it until it volatilizes and you’ve got a beautiful comet for a few loops around the Sun.

    Hard, rocky asteroids, assuming they have materials to mine, will have huge problems that must be solved before we can exploit them. Not the least of which: How do you get the raw material tonnage down to the Earth where it must go to have its greatest value? You can’t just drop it into the atmosphere; you’re going to need some kind of re-entry vehicle and parachute. How many tons are you limited to with that kind of re-entry technology?

    And I think it would be impossible to launch entire industries to set up zero-g manufacturing to build widgets for Earth-bound consumers. Again, how do you get enough tonnage of finished products to Earth to keep the price low enough to sell? You’ve got built-in costs due to the launching and landing of spacecraft that would make an asteroid made of pure gold too expensive to mine. We have a tough enough time mining here on Earth without taking it to the asteroids.

    But we should go and have a look. There is a proposal making the rounds at NASA to have a deep space ‘shakedown cruise’ of the CEV to a NEO asteroid. When I read that, I felt you couldn’t ask for a better mission to test the CEV prior to a Mars mission. The mission is estimated to be around 30 days round trip and the rigors of a Mars mission of 2 years are avoided while technique and technology are refined in a challenging deep space mission.

    Since NEO asteroids hold the potential for the end of humanity, what better mission could be conceived to develop our rendezvous techniques to ‘nudge’ a doomsday asteroid into a benign orbit. I hope to have some more information on this soon.



  38. One more proverb by someone you al might love…

    “Look t the future, as you’ll spend the rest of your life there”
    George Burns, born as Nathan Birnbaum
    A US-actor and comedian
    born 20.01.1896 in New York City (New York), USA
    died 09.03.1996 in Beverly Hills (Kalifornien), USA

    I like to say to Frank, who is probably a very decent, and warm individual. Think positiv and remember: “Scientists LOVE surprises, while Engineers don’t”
    Some scientists have been called dreamers, because their were too far ahead of the crowd, like Albert Einstein, who is still ahead.
    To realize the dreams, the ideas people like us, scientists and twits come up with, we need each other.
    Stay cool:)

  39. Frank,
    you are not only a decent human being, but have a very sober mind. As long as we measure everything in profit, we will be doomed.
    Those who have accumulated prohibitive amounts of money could only do so, because other could not…

    That’s capitalism:) In the end (I hope not) those will find out that money can’t be eaten…

    The whole idea of the moon as a base for further space exploration is still not making much sense to me. A large rotating Space Station creating inertia as a would be gravitation, seems to me more feasible. Of course we would need to haul everything up there. But who says that the next space ship to Mars has to be build of metal? A two[+] component foam could be used to create containers and a lot else…
    Our ISS is not the smartest idea. But that rotating SS has been an idea of a dreamer (A.C. Clarke)… therefore not good for practical application… ?

    During the Saturn V era, correct me if I am wrong, burnt out stages floating around before burning up in our atmosphere after reentry could have been used as stages to build a circular Space Station (huge diameters), why was this not considered? Or was it.
    You are of course right when you say that no-one with a solid foundation in Math and Science will go anywhere in this world, but please include imagination and creativity and have my support.


  40. Everything is completely impractical, usually imposssible, often unthinkable — right up to about three months before somebody does it. Three months after, it’s obvious; three years, a commodity; six years, and the marketing guys are angry if they can’t get it in taupe. Twenty years later, a new generation of kids snorts at the old farts who remember a world without it.

  41. Frank,
    I’m amazed at your fundamental misunderstanding of centrifugal force. (July 8th post) It has nothing to do with the Earth’s gravitational field and the acceleration is due to the constant change of direction of a rotating object:
    Fc = mv2/r, where Fc = centrifugal force, m = mass, v = speed, and r = radius.
    The force is supplied by whatever constraints that prevent the object from continuing its motion in a straight line and is constant at a constant rotational speed. You do not increase your rotational speed anless you want to increase the force necessary to prevent the object from moving in a straight line ( the “g-force”).

  42. Frank, Frank, Frank….You clearly have no understanding of the dynamics of rotating bodies, and your comments to Blueheron are completely erroneous, but we’ll get to that. First of all, please refer to Einstein’s notes on Special Relativity, in which he proves the equivalence between weight caused by acceleration due to mass (the Earth) and that imparted by an accelerating frame of reference ( e.g. a spinning space station). In the case in question, a rotating body (the space wheel) possesses angular momentum, which is a specific constant for each point on the structure, and if you are standing on the outer wall (the floor to you), so must you. Now, if you jump straight up in the air toward the spin axis of the wheel, you will actually move forward of your original location on the floor. This is because angular momentum is proportional to angular velocity and distance, r, from the spin axis. Since your angular momentum is constant, as r gets smaller, your angular velocity must increase, and you will follow a curved path which will eventually land you back on the floor of the space station at a different point (try to land on your feet). If you think you can follow the math, let us know and I will post it on this site, but I think you should listen to what Blueheron had to say. ( also, try the NASA sites which refer to the subject of spin-induced artificial gravity. Theoretically, no problemo, but there are a heck of a lot of engineering and safety issues which would have to be resolved). BTW, the technology to produce a propulsion system capable of accelerating at a constant 1 G for weeks at a time is pure science fiction right now. See me in 50 years or so and maybe things will have changed. All the best. T Davis

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