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.

59 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. [quote]# Frank Says:
    March 23rd, 2008 at 5:05 pm

    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. [/quote]

    Frank, you’re a ray of sunshine on sunburned skin. It’s only mildly ironic that you would mock Star Trek when we have a Space Shuttle called Enterprise. It is because of Science Fiction that most people have an interest in Space Exploration. It certainly has nothing to do with the innate charm of most engineers.

    Spaceflight is expensive and dangerous, we are reminded of this fact by Politicians incessantly. It is a risk that people have chosen to accept. It is the Job of Engineers to figure out how it can be done.

    I can barely express my nigh immeasurable gratitude that you would stoop so low as to even qualify my “juvenile musings that are insulting to the real engineers”. I can only assume that the rest of the people you insulted feel the same.


  17. 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.

  18. 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.

  19. 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?

  20. 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…

  21. Nobody seems to get it.

    Everybody has these “wonderful” ideas because, however inspirational Star Trek may have been, you think that Star Trek is the way science ought to be. I’m sorry to rain on your parade, children, but science defines what’s really out there in the very real world, no matter what you think to the contrary. Dreamers sitting in their bedrooms playing video games do not design spacecraft and the related support systems. Real people with a real grasp of the technological hurdles (Engineers … there’s that word again) would be shaking their collective heads in disbelief at the utter nonsense (yes, you should feel insulted) posted to this page.

    Just for starters, if lava tubes (assuming they exist) turn out to be a viable option for a moon base, how many flights to the moon do you think it will take to find a lava tube? How do you survey it? What equipment will you need to do the survey and how many flights to deliver that equipment? Is anybody prepared to enter a totally unknown environment like a lava tube (is that “floor” you’re standing on solid enough to support you 1/6 weight?)? And in a vertical tube how do you suspend the people and equipment to do the survey much less the construction? And we haven’t even gotten to the construction portion of these silly dreams (yes, feel insulted again). How many flights have we “made” thus far? How much money do you think your ideas have spent so far?

    None of you sound like you’ve done any construction work on Earth. I’ve been an engineer at the construction of two nuclear plants that took 15 years to complete. And that’s with resources readily available and no space suit to deal with!

    Think about this: How many flights to get just one crane to the moon outfitted for life support and the dusty conditions. And it has to be all electric because there’s no atmosphere to run a diesel engine, but you knew that, didn’t you, kiddies. How do you harvest the megawatts for that one crane? How many flights will it take to deliver the solar cells that will cover hundreds of acres for that one crane? What equipment will you have to get to the moon to build the solar farm? How many flights to deliver the relay and power conversion stations for that one crane? How many flights for the tonnage of the electric cabling? Do you bury the cable? Now you need extensive underground work to protect and insulate the cables. What are you going to use to excavate? It has to be electric too. Suspend the electric lines from towers as we do on Earth and how many flights to deliver the very-awkwardly shaped, very heavy towers and the insulators. And you need an electric crane to build the tower to provide electricity for your electric crane! Circular logic, anyone?

    Oh, I forgot… we’ll microwave megawatts… something we can’t do here on Earth or anywhere else.

    Oh, yes, a nuclear plant… complete with all of it’s shielding and meticulous maintenance, plumbing and support infrastructure requiring a dedicated work force. And it would have to be a plant similar to what we have on Earth, Pressurized Water Reactors, because direct conversion, RTG, only generates low wattage. Your crane will operate in the kilowatt range. Pressurized water? My, my…now we have to get thousands of cubic feet of very precious water (at 62.5 lbs per cubic foot at launch) and the boron used to mediate the nuclear reactions to the moon. And then we have to transport it from the delivery ship to the reactor (can anyone spell “large diameter pipe construction”?… I knew you couldn’t). So, how many flights and its attendant risks and expense have we made for these silly ideas?

    And this silliness about a space elevator? Come on, children, put down the sci-fi and learn some principles of engineering. We have nothing in materials science now or in the foreseeable future that can support anything more than a mile high. We are very near the limit of what the best and hardest concrete can support. Where would you put it? At the equator? The Earth does not rotate smoothly. You’d never get it finished (assuming some miraculous discovery in material science… forget nanotubes, kiddies) before it would be whipped like a tall reed in a breeze exceeding the sheer loads and come crashing down. And when you allow the ionosphere and it’s ever-present charge to go to ground, then what? And what about the impact on the weather, and other environmental impacts? And all of the aforementioned is assuming it can be built, which it can’t.

    Go back to your video games and fry your brains some more. But content yourselves with the thought that in spite of your silly nonsense (that’s one final insult) real engineers are solving some very difficult problems and we’ll eventually get to the Moon and Mars in spite of your foolishness.

  22. 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.

  23. 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.

  24. i did not say it would be cheap and i didnt say it would be easy. but you have to at least try to think of somthing that might work. at least i sugested that we use solar collection, which improves in effectiveness every so often. obviously you wouldn’t send manned rovers to search for an adequete site, you would have to set up a system of satelites with the technology to survey the landscape (no i dont know exactly what they are, so f*** off!) as well as under the surface. i am not entirely stupid either, obviously the wall strength will have to be tested before it can be used and yes i know that will cost a TON of freaking money and time and manpower. i said that the elevater had a signifigantly better chance on the moon, which might still be really small, because the lack of atmosphere and materials needed to build it. but i can only do so much without a degree. mabye you should try and push us in the right direction, tell us what might be feasable and what might not, eliminating completely rediculous ideas instaed of acting like a total bad ass with your credentials and degree making yourself look like a total jerk.

  25. i do plan on studying civil engineering at osu this fall to build high rises and i would like later to help with projects like this that might actually come to be and am not totaly brainwashed with videogames. so screw you and go back to your “intellectual” circle.

  26. Oh, I don’t know, Mr Sniffles, how about every single thing created by humankind, including, but not limited to, the extraordinary Apollo program. No engineer was dragged kicking and screaming there. And it was engineers who were in upper management at NASA who advised Kennedy prior to his historic “We choose to go to the Moon” speach.

    The parent-child relationship of Necessity and Invention is what drives innovation. But, that said, we can only invent and innovate from that which we understand. Sitting in a bedroom burning yourself out on video games and then “postulating” solutions to very difficult engineering problems based on your “understanding” of science as written in the pages of a sci-fi book or a TV program, well, I think my contempt for that approach should be plenty obvious.

    These juvenile musings need to be replaced with a real-world understanding of structural mechanics and dynamic processes. At that point, these bedroom trekkers will begin to see the enormous challenges their cavalier assertions dismiss. But, as we all know, that will mean leaving the bedroom, the video games and all pre-conceived notions of science behind and do some very hard work learning how the real world works. I’m not holding my breath.

    I recall a recent thread on a website based on an article about how the Mars rovers were losing power because of dust build-up on their solar panels. It was infuriating to read the responses and sense the “outrage” that these simpletons were spewing because NASA didn’t think to put — are you ready for this — a feather duster on a mechanical arm to wipe off the dust. How demeaning of that superb engineering achievement, those outstanding little rovers. One cogent reply attempted to outline the parameters of the mission and the limited weight they could carry to Mars and he was blown off as some kind of idiot.

    Conceptual engineering, particularly the kind we off-handedly call “rocket science”, is the absolute pinnacle of human intellectual achievement in the engineering disciplines, only surpassed by the engineers trying to contain the forces of the sun in their fusion reactors. And I don’t wish to slight any of the other engineering disciplines but I think, to a person, they would agree with this evaluation.

    To blather inanely about fantasy technology as though it will just happen overnight while we’re asleep is, most assuredly, an insult to the profound achievements that these extraordinary people have and are providing. People talk of stellar warp drives as if they are in the labs and just a few years away. Wishful thinking ain’t gonna do it. It takes logical, rational minds to probe nature for it’s secrets. And then, understanding that, we can proceed to real world application. To just blithely dismiss the organization, cooperation and creative efforts of the real heroes of our vaunted technological society as “just” engineers who have to be “prodded to do their job”, well, go to a desert island, Mr Sniffles, and start putting the society of your choice together. I suspect you’ll be a while. I further suspect you won’t exceed the meager managements of Robinson Crusoe.

    I will continue to take up the cudgel in the engineers’ defense against this blithering mob of dimwits.

    Get back to school and learn something worthwhile, you twits.

  27. Frank,

    Why do you feel the need to insult people? All of the above mentioned ideas are dreams and it is the role of the engineers to determin the feasability of and possibly design projects from ideas. In the 1940’s everyone would have thought the idea of putting men into orbit was nearly impossible and that men on the moon could not happen in their life time. We all no that many of these ideas are dreams, but exploration is often fuelled by dreams. Additional while you are listing all of the real world problems associated with large construction project you repeatedly refer to the “crane” although this might be a neccesary tool it would not need the power a terrestial crane would, as the moon only has 1/6 earth gravity it will be much eawsier to move large, heavy objects. Don’t be so hard on the dreamers, they often have the ideas that engineers turn into reality.

  28. “I will continue to take up the cudgel in the engineers’ defense against this blithering mob of dimwits.”

    Ironic that you’d choose something as crude as a cudgel to defend Engineers, I would think perhaps, a slide rule to be more applicable, but I doubt Engineers need your defense, most have pocket protectors. Tell me what use Knowledge is without the Imagination to apply it creatively? Look around you right now and tell me what it is that you see that wasn’t at some point first Imagined and *then* Developed? Do not dismiss the criticality of having insight that is not bound by a contemporary understanding of our world. It is an ability to think rather than to simply know that propels our species forward.

    My musings were, as were those of so many others, suggestions in the hope that someone might find inspiration. Creative Spark is one of the myriad hallmarks of our species. You have chosen to assume our thoughts were posed as an affront to Engineers, I know this is not true, because I was not affronted. The singularity within our race that truly sets us apart is our ability to imagine. What is interesting is that thus far your Imagination has yeilded unto you only the apparent misconception that everyone perusing and replying to this thread is a juvenile that fixates on video games, this at least is the perception of “us” you have Imagined for yourself.

    It’s intriguing that you seem to think all of the ideas posed were derived from Science Fiction. I have more computing power in my Cellphone that what is present on the Voyager Space Probes and those were Engineered and Launched only thirty years ago. What is Scientific Reality today is quickly being overwhelmed by a fast approaching tomorrow. You come across as stodgy and contemptuous, don’t assume you have a monopoly on knowledge.

    You earlier asked a great series of questions regarding the myriad hurdles that must be overcome to see any of these suggestions rise to fruition. In response to those questions I am compelled to say, “You’re an Engineer, figure it out”. I am not disparaging the achievements engineers have made, but you seem to believe that Engineers are the sole impetus for development. The advances we have seen and will continue to see are to be celebrated by Everyone. The Saying was “One Small Step for Man…” Not, “One Small Step for Engineers….”

    You have repeatedly called *Us* “Children”, “Kiddies”, “Twits” and “Juveniles”, I can scarcely begin to explain to you how cantankerous this makes you sound. I am almost surprised you have managed to glom onto this newfangled technology we young hooligans like to Call the “Personal Computer” and it’s child “The Internet”. Your mind shows commendable elasticity for a geezer. You use statistics the way a drunken man uses a light pole, for support rather than illumination, but I digress.

    In closing, I will share with you a rather well known quote from a man admired by Dreamers and Engineers alike,

    “Imagination is to Knowledge what three is to one.”

    ~Albert Einstein~

  29. Sorry, Silver Thread, I’ve known too many “creative” people who frittered their time away with wild and fanciful imaginings. Just being creative doesn’t do it. The real world intrudes, to paraphrase the Red Queen, no matter how many impossible things you can believe in before breakfast.

    Too many people believe that just to imagine is, as you put it, the hallmark of our species. And yet, it’s the practical engineer that has to sift through this detritus to find something that works. Indeed, that’s why all companies hire engineers and not dreamers. Engineers, my friend, are practical dreamers, for lack of a better term. They have to be to keep their jobs, Mr. Sniffles comments notwithstanding.

    When you say to an engineer, “build a bridge over this raging stream”. Be he/her an aborigine in the outback of Australia or a pocket-protected civil engineer/nerd working for “Big Construction, Inc”, they don’t take this piling and that span and slap them together, they first think of all the ways that the bridge can collapse and then NOT build it that way. That’s an engineer. They can’t dream out of context of the task before them. The results are their point and purpose and dreamers need not apply.

    Dreams are not worthless exercises in futility. But they are close to it if they can’t be translated into practical reality. From the aboriginal chief to the corporate CEO that bridge has to work and it’s real good if it works perfectly on the first try.

    Go back over all of the “dreams” in this post. I hope my comments got through to someone that practical limits to dreams are the stock-in-trade of achieving real-life space travel. Anything else posted is just tormenting electrons and a waste of HD storage. Yeah that’s hard on someone’s ego. Tough. There isn’t a moment of forgiveness in deep space or on a rickety bridge. And, believe me, NASA doesn’t have the bucks to hire anyone who isn’t a conservative, pocket-protected, work station proficient (sorry, I know how to use a slide rule but a work station is much more efficient) engineer with practical ideas that some might confuse with dreams.

    Werner Von Braun was a practical dreamer and he educated himself in the thoroughly impractical profession of rocket engineering in the 20’s and 30’s. He pored over every treatise written by Robert Goddard. As he built on Goddards foundation he got somewhere because he could articulate an arcane discipline to people who knew nothing of it and convey it’s utility. It is indeed sad that that utilty was for war and death. But his secret, practical dream was for human space flight. And look at what he did in 8 1/2 years after Kennedy committed the US to landing a man on the moon. Now that is what I’m talking about… the innovative engineers who meld their practical ideas … dare I call them dreams? … with the technology available, pushing the envelope where necessary and possible and “landing a man on the moon and returning him safely to the Earth”.

    These “kids” need to get off their duffs and learn the hard sciences. Throw the TV, videogames, iPods and all the other flotsam and jetsam of this distorted consumer society away and get to work. The final frontier is theirs for the understanding and their practical solutions to these enormously difficult challenges but ONLY if they learn how to think within the framework of reality.

    There is only so much money and only so much resources that will be committed to the endeavor of colonizing the moon. One failure or even a marginal success could doom any future attempts for decades to come. You can’t just dream willy-nilly. You have to be disciplined and, yes, knowledgable before you can dream or you’re just wasting calories.

    As to suggestions for the engineers at NASA? Fine. Make them. Just give them a little thought about implementation and application and ask yourself can this really work? How could it fail and how could that failure jeopardize the mission. If you’re honest about your answer to those questions you’ll do like a lot of engineers and realize that they weren’t such a good idea and quietly put it to bed. That will free up your mind to think of something maybe a little more practical, with a little bit better chance of success. I can’t put a number on this but I’ll bet there were ideas too numerous to count during the Apollo program that were considered, evaluated and discarded as impractical only to move on to the very few good ideas that did work so superbly.

    As for the “children, kiddies, juveniles and twits”? We are all children, kiddies, juveniles and twits until we’re not. You hold the key within that esoteric presence in the organic mass in your skull… your mind. Train it. Use it. Challenge it. Change the human condition. Explore the stars, from a practical point of reference not the silliness of Star Trek

    That, Silver Thread, is your challenge. Are you and the other posters up to it?

  30. 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.

  31. Frank,

    1. Every single thing that our species has ever accomplished or created was a result of somebody dreaming something up. Intentional or accidental. Yes, even fantastical dreams. Of course most of us are aware of our current limitations in resources in materials and knowledge. This is why we educate engineers. To make our dreams come true. The “dream” comes before implementation.

    2. Is this the wrong forum for people to express their opinions to an article and offer suggestions – however impractical they may be at this moment in time – or is this just for “Bachelor of Science degree” and above? I hope not, because I always like to hear ideas when it comes to all fields of science. Regardless of where the ideas come from and sometimes it only takes that one little “piece” to put it all together. Even if it comes from a “twit wasting his time watching Star Trek”. Oh, by the way… A lot of things that we take for granted today could be credited – to an extent – to Gene Roddenberry and his guys. They thought it up and the engineers made it work.

    3. I’ll bet you five bucks that 99% of the engineers today did play video games and watched or read science fiction when they were kids. At least I hope so. If they didn’t, then I will strongly suspect that they won’t contribute much to our society (off World that is).

    4. Lighten up. Give these people a break. Let them voice their ideas. There is nothing wrong with it. It is okay to correct, but there really isn’t much point to criticize. It’s also not productive.
    Go find yourself a girl (or get rid of the one you have) … 🙂

    More ideas, suggestions and comments, please!

  32. 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. 😉

  33. 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?

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

  35. 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.

  36. Al Hall,

    Your first point couldn’t be more wrong. Humanity did things because there was a need, not because some ancient forebear sat down one day and dreamed of something. No one dreamed up fire. An ancient hominid was near freezing to death or perhaps having his or her clan members dragged off by a predator in the middle of the night that focused his or her mind on a solution. Constant observation and the ability to draw relationships between disparate occurences led to the control of fire and changed our species as it conferred a survival advantage no other creature could comprehend, much less utilize.

    Humanity from its outset was beset by the scourge of survival. Not a single mastadon walked into their camp and obligingly dropped dead so they could eat for the winter. All it took was a belly-wrenching hunger and a few near-death experiences and the mind of our ancestors was focused on the need to survive. From that need, not dreams, came the spears to bring down prey and, over time and continual observation, the spear throwers, that multiplied the distance and striking power of the spear, became another of the contrivances of our survival.

    Natural selection weeded out the dimwitted as those with organized minds were able to develop successful tactics in the hunt. If your tribe had smart people who were more clever in the hunt than the tribe over the hill then you survived and the other guys didn’t. Life back then, as it has been observed, was nasty, brutish and short with not a dream among them.

    But here we are, so they did something right. And that “right” thing was focusing all of their early brain power on the pressing and incontrovertible needs of survival. This is what spurred the innovation and the engineering, primitive as it was, and added, bit by bit, to the survival base of our species. This will to survive that is imbued in our DNA is the driving force of our innovative nature giving rise to such ancestors as the tool maker, homo habilus, the handy man. Not a dream coursed through his brain that woke him up at night with an idea he had no use for and wouldn’t contribute to his survival.

    Dreams, my friend, confer nothing to the grand scheme of things. Cold, unforgiving experience is our guide. We ignore it at our very great peril. As I noted in a previous post, we, as a species, can’t know what we don’t experience. That said, even the “dreams” you hold in such high acclaim are rooted in reality we’ve experienced. Distort that reality with nonsense and we get the vapid traipse of the undisciplined mind as evidenced here in these posts.

    When our species went from a hunter-gatherer society to an agricultural one we were transformed again as a species. Never again would we be able to go back to our hunter-gatherer ways because agriculture conferred a survival advantage so great that it would be like giving up our ocean-going ships so we could return to swimming to cross the ocean. Agriculture was not dreamed up. It was the constant observation of the environment, the seasons and our unique ability to see cause and effect that brought crops to harvest and ensured our survival as a species.

    And we don’t educate engineers to make our dreams come true. The marketplace dictates what an engineer will design and build, not your dreams. Some entrepreneur has an idea, perhaps based on a suggestion by someone, which he or she thinks will make them very rich, conferring a decided survival advantage to the entrepreneur and his or her children. At that point they hire an engineer to build their idea. Is that a dream? Nope. A need was identified and exploited for profit. At its root it’s the need to survive.

    No matter what you think of space travel and the reasons we, as a species choose to take the enormous risk and expense involved, it’s ultimately about finding something that makes us fabulously rich or confers in some other way a profound advantage in survival. How many times has it been written that we must go into space to colonize another world for the eventual time when we finally wear this tired orb out and we can’t live here anymore. A bit farfetched at this point in time, but not wrong in its overall conclusion.

    On your second point: Yes, it is wrong to express silly “dreams” when the original article tries to convey just how difficult colonizing the moon will be from the infrastructure and transportation angle. Read the article again. Florian Ruess, a contributor, was dismissive on this particular point “…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.” This man, without saying it, doesn’t want to be bothered with “dreams”. And “lunar concrete” is a far cry from the silly sci-fi Star Trek “dreams” put forth in the subsequent comments. I’m not the only one who thinks that these challenges require rational, logical minds to innovate for the needs of a real, practical moon base. Dreamers need not apply.

    You’re right that it shouldn’t be ‘just for “Bachelor of Science degree” and above’. I’m a firm believer that sometimes the best solutions to some intractable problems come from those that aren’t inculcated with the “company philosophy”. But even an outsiders contribution, someone thinking outside the box, so to speak, still needs to be in the same room that the box is located in!

    And concerning your “Oh, by the way…”, there isn’t a single thing on Star Trek that can be found in our technology today. No warp drives. No transporters. No replicators. No tricorders. No phasers. No photon torpedoes. This fantasy entertainment, and that’s all that it is, has done nothing for the advancement of society except entertain the rational among us and fill the foolish heads of the rest with nonsense and contempt for real science. It is not, by any stretch of the imagination, a template for our future or a standard by which to organize society. It is entertainment and nothing more.

    Point 3: Video games and sci-fi as entertainment is fine. It’s the descent into an all-consuming abuse that’s the issue. I prefer chess as entertainment. But, be assured, that my wife would be making appointments with a therapist if I locked myself in the bedroom for hours on end playing chess on line. It’s the waste of time that I take issue with. And all indications are that there are way too many people — young and old, sad to say — that fry their brains on this crap and then can’t navigate a logical thought process much less achieve anything of note in school or life. Then they show up in forums such as this with their addlepated notions of science and engineering taking great umbrage at any criticism of their silliness.

    Point 4: Lighten up? Sorry, their prating foolishness needs to be called to task. Again, I point to the serious nature of the original article above and the need for rational thought and not the fatuous yammering put forth here.

    Which brings me to my original point that the puerile posts on this thread are insulting to the real engineers who labor to bring a real and functioning moon base to the benefit of all humanity. As I’ve said before, without a strong foundation in math and science, nobody goes anywhere in this world.

    Are these posters stupid? No, I’ve seen no indication that they lack the ability to understand the difficult lessons of science or math. It’s obvoius, though, that no one has called them on their nonsense or held their feet to the fire to understand the real world as it really is. That is the underpinning of my trenchant criticism.

    Oh, and a final note, I don’t need to find myself a girl or get rid of the one I have. My beautiful wife loves me just as I am and for all the “geezer” that I am.



  37. 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………………

  38. 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. : )

  39. 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.

  40. 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.



  41. 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… ?)


  42. Michael P.

    The showstopper for nuclear is the radiation component. It’s going to need a considerable shield to contain the radiation. Water, concrete and lead are excellent shields but all are extremely heavy and would be nearly impossible to transport to the moon in any kind of a cost effective way.

    Please keep in mind that for the forseeable future our access to the moon is going to be limited to what an Ares V can lift to the moon, which is about 55,000 to 60,000 kg. There are no figures I was able to find for the lunar landing vehicle but whatever the mass of the landing vehicle is you can immediately subtract that from your deliverable payload. It wouldn’t surprise me if the landing vehicle for anything you want to land on the moon is half of the total lunar payload, or about 25,000 to 30,000 kg.

    You’re also limited by the shroud length and diameter. The numbers may change slightly but at present the baseline Ares V 8.4 meter shroud has a 7.5 meter dynamic inner envelope diameter and an 18 meter envelope height. Alternative shrouds being considered include one with a 12 meter outer diameter, 10.3 meter payload diameter and 21 meter total height.
    (ref: So, whatever gets launched can’t exceed these maximum values in height, width and weight.

    Another often overlooked factor is the cost. The vehicles are roughly estimated to cost from $350M to $500M per vehicle. Expect the vehicle cost to rise and I’m sure that number is empty, not ‘wet’ on the pad ready for launch. With this in mind, there is going to be a lot of incentive for the designers, planners and engineers to get as much to the moon in as few trips as possible. This is going to place a premium on low mass, compact design and minimal-to-no construction when the payload gets there. Nuclear reactors, even the small ones, are going to be prohibitively heavy.

    And there is the catastophic failure factor. An explosion on the moon of a reactor or any of its components would not only knock out the major source of electrical power and destroy a critical asset but would, more than likely, scatter some very nasty radiological debris making the area inaccessible for centuries! It would be next to impossible to clean up. It would be an “Abandon in place” resolution. I honestly don’t see nuclear as an option.

    Solar cells will more than likely provide initial power but as demands for watts goes up– and it will as the construction project gets serious– the demand for power will exceed the solar cell output very quickly. Would a solar furnace provide the answer?

    Questions abound on a solar furnace: can a system be designed that’s small enough, light enough, with high enough efficiencies to justify the investment of an Ares V or two? Is a steam cycle even possible in a low gravity environment without air? The steam loop would have to be in a pressurized enclosure to preserve the water. And even with the best of design, water would still be lost and need to be periodically “topped off”. If the indications of water ice in Shackleton Crater pan out this may not be a problem but if the water ice is not there or impossible to get to, you’re transporting water from Earth, a very expensive proposition.

    Failure modes of a solar furnace might make this a showstopper as well. Steam is a nasty, temperamental critter. If there was a catastrophic failure, as in a steam explosion, there wouldn’t be any radioactive residuals but there would be one heck of a mess and it’s quite possible you’ll be left without enough electricity to continue the mission. It’s safe to say the lunar mission would, at the least, be highly compromised and quite possibley be over for a while as the colonists high-tail it home.

    And all this surmise proceeds from the assumption that a small solar furnace can generate the power output required to make it a viable lunar colony technology. Truth is, I don’t know enough about the intricasies of the solar furnace to make anything but a guess about its efficacy. I would very much like to be a fly on the wall as the arguments go back and forth in the planning meetings for the lunar colony.

    Concerning the CG, the perpendicular fuel tanks you mention are for the RCS system and, yes, they were located equidistant from each other around the center of the crew area. The center of mass of the LM, however, was not through the center axis of the engine (the center of thrust). Look at the schematic of the LM ascent here:

    for a very good description of the stability issues of the ascent stage of the LM. Note his reference to the off-axis thrust and the consequent rotations in the paragraph above Fig. 6

    The oxidizer/fuel ratios also contributed to the rotations as the tanks emptied. Here is a space souvenir I wouldn’t mind having and, yes, it would be in my livingroom too. The oxidizer/fuel ratio is noted as 1.60

    I recall an interview on the History Channel where Aldrin commented on the LM rocking from side to side during the ascent. If memory serves, he said, even though it was expected, it was a bit unnerving until the fuel supply became low enough that the oscillations were small to non-existent. I couldn’t find a copy of the interview.

    Here is a video of the launch of Challenger during the Apollo 17 mission. Watch closely and you can see it tip to the left and then right itself as the RCS makes its correction.

    Concerning the Star Trek tech: Automatic sliding doors have been around since the ’50’s in malls and shopping centers. (ref:

    And cellphones I don’t think are a good comparison to the communicators. A closer comparison might be the satellite phones that people use in the middle of nowhere to call for a rescue or to call their friends to say “Guess where I am right now.”. They’re bigger than the Star Trek communicators but I’ll give you that one even though it can’t call an orbiting starship.



  43. 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.

  44. 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.



  45. 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.

  46. 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.



  47. 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.

  48. 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.



  49. 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:)

  50. 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.


  51. IKE:),

    Thanks for your kind words. I’ll admit I was a bit hard on some of the writers but the cavalier regard for the difficult job of the engineer was more than I could let pass. If nothing else, I hope everyone is a little more respectful of this very difficult profession.

    Regarding a spinning space station: It’ll never work, with all due respect to A.C. Clarke. We are beguiled, once again, by science fiction when we should carefully consider science fact. Rather than asking ‘What is gravity’ perhaps we should be asking ‘What is weight’? The distinction being that gravity is the force that is exerted but weight is the result. Weight is what all creatures have adapted to and weight on our bones and muscles is the reason for our morphology and why extended period without it are so damaging.

    A counterintuitive aspect of gravity is that it is always accelerating us towards the center of the Earth. As you sit and read this reply you are not in motion but you are indeed being accelerated towards the center of the Earth. The resistance of the Earth’s crust counters this acceleration and you feel ‘weight’ as a result.

    Since the first cyano-bacteria winked into existence the one environmental factor that has not changed is the pull of gravity. It has never stopped and is virtually unchanged since life arose. It is the only environmental factor that that can be said of. Every creature that has ever lived can trace it’s morphology and evolution to this constant acceleration towards the center of the Earth and the resistance of the crust. Take away the influence of ‘weight’, as in a 6 month freefall to Mars, and the consequences, as we are finding out, are profound and extraordinary.

    Many people are transfixed with science fiction solutions to this issue. Many suggest spinning the crew quarters of a Mars vehicle. It simply won’t work. Again, our sense of ‘weight’, which is what we are adapted to is a function of acceleration. A spinning crew quarters would generate a sense of ‘weight’ as long as the spinning continued to accelerate but you can only spin it so fast before practical limits stop you.

    Consider your car when you step on the gas: As long as the car is accelerating you are pressed into the back of the seat. As soon as the engine power peaks and the acceleration falls off you are no longer being pressed into the back of the seat. That is what will happen when a spinning spacecraft stops accelerating its spin. It may be doing 20, 30, 50 or 500 rpm’s but once it stops accelerating ‘weight’, the result of acceleration, ceases.

    People have pointed to centrifuges here on Earth as examples of the technology that would solve the zero-g problem. They forget that all the time that the centrifuge is spinning it is in the gravity field of Earth. The test subjects are being pulled into the seat and held there by the Earth’s gravity as the centrifuge spins. As the body is being flung to the outside of the arc of the centrifuge, the angular momentum generates the g’s on the body. The Earth’s gravity field creates the illusion of the centrifuge being solely responsible for the increase in g-forces.

    On a spinning spacecraft, without the mass of the Earth to create that background g force pulling the body into contact with the seat, ‘weight’ would not occur. An astronaut could stand in one place and pick his/her feet up off the floor and float in place, probably hitting the back bulkhead as the rotating structure moved beneath them. Spinning is simply not a viable solution.

    If, however, an engine can be designed that would constantly accelerate the spacecraft, ideally at 32 feet per second squared, this constant acceleration would create the ‘weight’ perception to the human body without the need of an Earth-like mass. Enormous speeds would be achieved, particularly at the halfway point where the vehicle would begin a deceleration, again at 1-g thrust.

    Consider the mission scenario: leaving Earth orbit the engines are powered to 1-g acceleration. All of the occupants feel normal Earth weight and function as they would if they were, say, on a submarine. At the half way point, the vehicle is turned around and for the remainder of the flight, until orbital insertion around Mars, use the engines to decelerate. The occupants still experience a normal 1-g environment during retrograde.

    I have read speculative papers that say such a ship could be at Mars in 2-3 weeks. If these numbers are valid, the benefits are manifold. Gone are the tribulations of 6 months of weightlessness. The psychological effects of being cooped up in a ‘tin can’ are minimized. The long term exposure to the radiological environment of trans-Martian space is significantly reduced. And, as the engines get more powerful, the spacecraft habitat can become more protective by installing lead shielding. The efficiencies of these engines should reach a level where mass will be a minor consideration. It is, I believe, the only practical solution to a host of issues that must be dealt with for a successful mission to the Red Planet.

    So, my suggestion is that we place our limited R & D space dollars into the development of an engine- be it an ion drive or a nuclear engine – that can burn for the entire transit to Mars generating 1-g of acceleration and deceleration. If we can accomplish that we will be a space faring species in the tradition of the sailing ships of old, in control of their voyage and destination, rather than a drifting raft fortuitously aimed.



  52. 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.

  53. 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”).

  54. blueheron,

    I have no misunderstranding of centrifugal forces. I’ve said spinning won’t work as people expect.

    The problem with spinning is that in order to benefit from angular momentum you have to stand in one place, in contact with the ‘floor’ at all times.

    Attempting to walk in this environment will not be at all like walking on earth. In fact you may not be able to walk at all.

    On Earth, if you jump up you have broken the bond of gravity with just the strength in your muscles. During the execution of your jump, once contact with the Earth is lost, no more energy can be imparted to your leap. So, the mass of the Earth, gravitationally weak as it is, inexorably overcomes your upward trajectory and down you come. Human locomotion (walking) is a series of graceful mini-leaps that utilizes the give-and-take of this mechanical interaction to create our mobility. We push off with enough energy in our walking gait to break free of gravity just enough to allow us sufficient elevation to reposition our feet before the Earth’s mass pulls us back down into contact with the surface. Graceful coordination makes the bipedal locomotion of humans an almost absent-minded and secondary function as we go about our lives.

    That same graceful push-off that initiates and sustains our walking gait on Earth will not work on a spinning space station or space craft. Once you impart enough energy to execute a normal step you overcome the artificial 1-g imparted by the angular momentum. Up you go and you are not coming back down. You’re headed for the ceiling only to be bounced off if you can’t grab anything to hold on.

    I’m afraid any attempt to move in such an environment would be next to impossible without some way of keeping you in constant contact with the ‘floor’ so the angular momentum can be imparted to your body creating this deceptively artificial gravity. Magnetic boots, anyone?

    Even if this fundamental flaw didn’t exist the engineering and design of a spinning vehicle would be prohibitive. Everything that spins in space must be balanced to within fractions of a gram. A slight imbalance and an oscillation can be built that could very easily exceed the design limits of any craft. Ask NASA about out-of-balance spacecraft spinning to their destruction.

    Imagine the Commander of a spinning space station with, say, a 20 person crew calling a staff meeting. Roughly 2 tons of mass would converge on one location on the station. Any movement of mass inside the space station or spacecraft upsets the balance and an oscillation starts. To counter this you’d need an active counter-balance system of masses. Now we’re into sensors, computers and interfaces with some method of moving an equalizing mass on the opposite side of the vehicle.

    Then, of course, there’s the rotational torque imparted by the spin. If you want to keep any part of the vehicle stationary, say, to point your directional antennas or properly vector your engines, you’ll need an identical mass spinning in the opposite direction. We’re talking huge masses and very complex systems. Again this is all assuming that spinning works but, as I noted above, losing contact with the ‘floor’ while you walk is the ‘deal buster’.

    If spinning was the solution to the weightlessness issue you could be assured NASA would be well along in the R&D of the hardware and there would be a module on ISS devoted to this R&D. I haven’t seen a dime in any appropriations for the design of a spinning spacecraft or space station. I have seen some research on a spinning bed that astronauts would take turns using to retain robust gravity-dependant physiologies (which is virtually everything about the human body). I’ve seen nothing more about it so I have to assume it wasn’t a viable technology.



  55. 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

  56. Mr. Davis,

    I’m sorry I haven’t been able to reply sooner.

    If I have read your reply correctly, what you have said simply confirms what I wrote to blueheron.

    Quite honestly, the math that you’re questioning that I can follow is, according to you, proving my statement that locomotion in a spinning container will not be like walking on Earth. In fact, as I’ve noted before, it will be dangerous to the point of non-utility.

    And, respectfully, what do you ‘know’ about the dynamics of rotating bodies? Nobody has any empirical data on what it’s like to live or work in a spinning container because, obviously, you need to be in a spinning container on orbit to do the proper studies. Need I point out that no orbiting research facility exists or is planned, perhaps because the problems are quite obvious to the engineers working the issues. It’s a thought experiment where the math is elegant but non-applicable in the real world.

    All the math in the world (or space) is not going to make for proper locomotion on a spinning vehicle. Given the limitations of a space station, you can be sure there won’t be any luxuries like expansive modules to allow for the arcing steps your math claims … as you be sure to land on your feet.

    I’m sorry, I disagree with your example of ‘an accelerating frame of reference’. A space station spinning at a constant rate is not accelerating so there isn’t accelerative ‘gravity’. What you’ve got, as you know, is the inertial energy of your body wanting to continue in a straight line, resisted by the ‘floor’ of the station spinning at an angle. That resistance imparts the sense of ‘weight’ but it is not accelerative gravity. As long as you don’t move and stay in contact with the ‘floor’ you’ll feel this ‘weight’. Attempt normal movement and all bets are off. And that’s the deal killer for this idea. As you noted, theoretically it works… until it doesn’t. And as I noted, the engineering — if the idea had some merit — would be massive, complex and prohibitive.

    And you’re right about the 1-G propulsion system being temporarily science fiction. My estimate puts it 75 to 100 years out; with a
    focused program possibly sooner than that. I’d like to agree with your optimistic 50 year time frame but there are some significant engineering challeges to deal with, though none appear to be insurmountable.

    As I said previously, we’ll go to Mars ‘for the hell of it’ … just to say we did it. We face the very real prospect that we may not get that first crew back. Apollo 13 proved how close we were to failure on every moon mission. Mars expeditions won’t be any better until the voyage there takes only 2 to 3 weeks with a constant propulsion drive. So, we may very well tempt the fates and make a voyage to Mars in the 2030- 2040 timeframe that NASA is positing. We might even go back if the first mission is a success. We’ll colonize, exploit for profit and live there only after we develop a constant propulsion drive.



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