Feb 3, 2012

My case for Mars

Posted by in categories: habitats, space

There has been a lot of discussion about a lunar colony or at least a base as a precursor to sending humans to Mars. The advantages cited are its proximity to Earth, the use of telerobotics for construction, and the fact that we’ve been there before. My position is that it would be far easier to establish a self sufficient colony on Mars with existing technology.

One thing everyone agrees on is that local resources will have to be used. We now know that There has been a lot of geological and hydrological activity on Mars that has segregated and concentrated useful ore bodies that can be exploited with current extractive technology. One type of mineral of interest is the occurrence of iron and magnesium carbonate formations on the surface. Magnesium carbonate is easily converted by heating to magnesium oxide, the primary component of a type of cement that I am researching as a construction material for Mars. The widespread occurrence of sulfate salts also gives reason to believe that metal sulfide ore bodies are also available there. This type of ore can easily be refined with simple electrolytic equipment. The same metal refining on the Moon would require grinding and processing basalt with a lot of heavy equipment.

I would argue that Mars also has a more friendly environment. First, it has higher gravity than the moon, at 38% of Earth’s gravity. This may prove to be significant in minimizing the health effects of reduced gravity. The higher gravity would also aid in many industrial processes such as ore separation and concrete consolidation. Mars also has an atmosphere, however thin. While 4 to 8 millibars may not sound like much, it is enough to burn up a lot of micrometeorites before they reach the surface, reducing the danger of micrometeorite damage. It may also help reduce the danger of galactic cosmic rays, but that will need to be tested. One thing that is certain from my own research is that the thin atmosphere is enough to allow magnesium oxychloride cement to cure before a significant amount of water has evaporated from it, and prevent boiling during the curing process. On the airless Moon, this type of cement would boil violently and the water would evaporate before it would cure. The total lack of atmosphere on the Moon would preclude the use of any cement that depends on water for curing.

Dust will be the biggest challenge to machinery in either place, and I argue that it is much less of a challenge on Mars. We have already studied lunar dust, and it is composed of fractured particles that retain sharp edges and points, with no mechanisms for smoothing the surfaces such as wind or water movement. This makes Moon dust very abrasive to machinery (and air seals) and very irritating to human tissues on contact. Mars has annual wind storms that blow dust around the planet, and has had flowing water recently in it’s history. This would serve to smooth out Martian dust particles to something more closely resembling the kind of material found on Earth, which we can more easily deal with. As further evidence, we have had rovers survive multiple dust storms and keep operating. I would say this is as much a testament to the Martian environment as it is to NASA engineers. Additionally, the dust has been found to be largely magnetic, meaning that magnetic filtration could be used to keep it out of habitable spaces.

Some would argue that solar power is more abundant on the Moon, but the problem there is that it intermittent. 14 days on, then 14 days off. Power either has to be stored for two weeks at a time, or produced from other sources. On Mars, you just need to get through a single night. The dust storms can cause problems of course, but that is at most a month out of every 22.

Finally, there is the question of water. On the Moon, water ice is probably at the bottom of some deep craters near the poles. It can probably be mined beneath the surface, we are just not sure how far down we need to go. On Mars, snow has been observed made up of water ice, and water ice has been seen just beneath the surface in rover tracks. It appears to be everywhere, just below the surface.

The Moon may be closer as the bird flies, but in terms of energy to get there, Mars is not much further. The biggest challenge will be getting humans there alive, but once that is done the learning curve once we get there is much shorter. Instead of developing new and untested industrial processes to exploit lunar resources, we can use proven technology to exploit Martian resources with much less effort. The prize is there for the taking, and there is no point in stopping on the way to build a temple to Luna.


Comments — comments are now closed.

  1. anemet says:

    Very nice post :) I think we should both exploit moon and mars, like two parallel colonization missions, this way we increasing the chances of having at least a success( no, it’s not like chasing two rabbits and losing both of them!) The moon is closer and has resources, so why leave it there without giving a try? On the other side, Mars has been a colonization dream for decades, it’s much closer to what might be considered a second home…

  2. Keith Henson says:

    Power satellites are another route to Mars. They make no sense at all unless the cost of lifting parts to GEO gets down to $100/kg. That’s at least a factor of 40 below the best SpaceX thinks the Falcon Heavy will cost. Since the majority of a Mars mission cost is in the propulsion, a Mars project in that context wouldn’t cost much at all. The only way now known that the cost could get that low is beamed energy. Applied to the outbound mission, Ve would be close to 9 km/s. Longer term, we just ship a power sat to Mars. Beamed energy lets you get up and down from Mars on water, it stops incoming traffic and powers traffic back to Earth. And, it gives a Mars surface mission as much power as they want.

  3. JohnHunt says:

    That was a good defence for Mars first. But there remains a few unaddressed issues.

    Eric, would you claim that Mars would also be less expensive as a first location to establish a colony than the Moon? I wouldn’t. I would say that this is perhaps the most important issue for choosing the first location to colonize. I would agree with you that Mars is a better long-term colonization destination. But from a survival-of-the-species standpoint, what should matter to us tremendously is where we can FIRST establish a self-sufficient colony. And I think that the cost of establishing that first minimally sufficient self-sustaining colony (MSSC) is largely the deciding factor. I think it makes a difference whether the cost for the first MSSC is $10 billion vs $80 billion. The first could be achieved through a “Lunar COTS-like” program. The second would probably require our convincing Congress (with all of their special interests) to cancel the SLS. We need to be practical here because time is not on our side. This isn’t just an intellectual hobby. We really, really need an MSSC.

    Secondly, due to the proximity of the Moon, lunar ice for propellant can be developed telerobotically. I don’t see that water ice from Mars would ever be as cost effective to develop in order to bring back to the LEO market. So, I see potential for economic sustainability with lunar resources whereas Mars would be an ongoing cost center. The commercial value of lunar resources could well be a deciding factor in terms of recruiting commercial investment as part of the development program just like the value of the commercial satellit business make companies such as SpaceX willing to match NASAs investment in COTS.

    So my two main arguments are primarily economic.

    I don’t see cement as being a deciding factor. Previous individuals including Bigelow have proposed using regolith-filled sandbags to cover habitats. Bags are really light. With no wind and little seismic activity, a sandbag igloo should work just fine.

    We know that the Martian atmosphere is insufficient to adequately attenuate cosmic radiation. I believe that it is generally recognized that a Mars habitat would need to be under nearly the same amount of shielding as a lunar habitat. As for micrometeorites, 5 meters of dirt covering (either Lunar or Mars) will be sufficient for micrometerorites. As for the benefits of greater gravity for separation, the biggest difference is between no gravity and 17% than between 17% and 38%. Remember the images of the spray from the wheels of the lunar rover? It settles down nicely.

    There are places on the Moon called Peaks of Eternal Light which we would certainly go to establish the first MSSC. The lunar night problem isn’t a problem for the first MSSC. Long-term yes, Mars is better. But we need to focus on ensuring the survival of humanity ASAP!

    I think that your dust argument is likely valid. However, remember that one of the martian rovers sustained damage to a wheel despite performing nothing near mining-level of activity. The Russian lunar rover, I believe, has the long-distance record for rovers. So the environmental difference may not be so great. However, for mining operations where dust is being kicked up, we need equipment to be repaired. On the Moon this could be done telerobotically whereas telerobotic repair on Mars is either not practical or cost-effective if done by astronauts from Phobos. It is argued that humans are necessary to repair equipment. If so, I would say that the short flight time to Luna with the much lower radiation exposure and the much less consumables (and hence fuel) needed is significant when chosing the first destination for an MSSC.

    Again, in the long-term Mars has a better water situation. But for the first MSSC, we know where to go on the Moon to get water at 5+% concentration in the regolith.

    I think that perhaps your strongest argument is the potential biologic difference between 38% gravity vs 17% gravity on the human body. For an MSSC, it is not only an issue of bone loss (which I think has just been proven to be solved by Fosamax and also a vigorous exercise regimen) and the immune system, but rather importantly, on the developing fetus. However, none of us know if 38% is sufficient to produce a reproductively viable baby. We really need hypogravity (not micro) research being done on the ISS. There are a number of solutions which are being explored in some space forums including centrifuges, tetherball-like, and other concepts.

    I have nothing against Mars. Long-term it clearly will support a larger population than the Moon for the reasons that you give. Indeed, in my plan, once we establish the least expensive MSSC (which will be on the Moon) and we give it a bit of redundancy, then I think that it makes good sense to head immediately for Mars. It is further away from Earth which is a good thing in terms of survival and it does offer better resources (such as a more easily accessible source of carbon). But the Moon will help make that next step easier. But first we MUST actually build the first MSSC which will largely be determined by costs.

  4. John,

    I agree with you that cost should ultimately be the deciding factor on where to settle first, and I still believe that Mars is the best choice by far. Most of the cost will be in transportation, and one of my arguments is that Mars has more of the types of concentrated ores that can be processed with relatively light weight equipment. Please correct me if I am wrong, but the lunar surface is mostly basalt and similar rock. Sure, the elements are all there, but think of the equipment necessary to extract the rock, pulverize it, separate the chemical components and then you can get down to refining it, which might require carbon for reduction. If we can fin concentrated sulfide ore, the refining process is far simpler and does not require carbon for reduction. The same is true for water. Think about the equipment required to extract water from the lunar regolith, then think about the equipment required to melt chunks of ice and purify the product in a solar still.

    The cement I mentioned is a type of high strength cement that can possible be used to build pressurized structures without metal or fiber reinforcement, again minimizing the equipment necessary for production. I have done some preliminary research on it that I mentioned and the rupture modulus of a basic concrete mix was enough to contain 8 PSI of pressure in a 25 foot domed cylinder structure with 8 inch thick walls with a safety factor of over 3. I am still working on a design study, but it may be possible to use a single SpaceX Dragon to carry equipment necessary to produce enough concrete to build a habitat within a few months. The habitat design I have in mind would be buried, of course, with access through an airlock at the top.

    As cosmic radiation goes, I know that the Martian atmosphere does not give enough shielding . I am thinking that it may reduce the radiation dose for people working on the surface. The same goes for micrometeorites. While colonists would be safe from this danger in underground shelters, work will still need to be done on the surface on the Moon or Mars.

    Gravity separation of ores is not comparable to dust being kicked up and falling back to the surface. with multiple components in a mixture, separation is difficult enough on Earth, so the more gravity the better. I have some information on buoyancy under different gravity conditions but I would have to find it and do the calculations. The fact is that the processes would be much slower under lunar gravity, requiring more equipment to process the same amount of material.

    On the subject of telerobotics, I think too much reliance on it would set the whole operation up for failure. We have all seen how a simple software problem or minor equipment malfunction can cripple a mission. Sure, robots can do a lot, but a human with a few simple hand tools can do far more, and do so far more efficiently. While robots can be designed and programmed to handle expected problems, humans are far more effective in handling unexpected problems.

    As far as the rest of our arguments (health effects, etc.) we will not know until we try it. Those are known unknowns, so I will not bother addressing them. We will have to wait and see who is right.

    One other thing, you mentioned available carbon. Are you talking about the CO2 atmosphere or have they found other sources of carbon on Mars, like graphite deposits? I have been working on the assumption of no fixed carbon on Mars.

    I am not arguing against settling the Moon, I am just arguing that Mars would be much cheaper and easier. I am also working on research to show how it is so. Hopefully I will have something ready for publication later this year.

  5. LarryD says:

    A non-trivial point: the moon is close enough that a rescue mission sent from Earth could arrive in time to actually rescue Lunar colonists. With current propulsion, this is not true for Mars.

    Eventually, we’ll have to take the risk. But the Moon seems a somewhat safer arena to practice in, in preparation for a Mars colony.

  6. Rlynh says:

    I hope I live long enough to see this kind of thing happen.

  7. mark l. says:

    IF gravity is a constraint that cannot be overcome…
    I’m thinking high speed rail around phobus or deimos.
    the construction of the track would entail building a track of 22 miles(phobus) or 25 miles(deimos).

    At a high enough speed, heavier earthlike gravity could be produced, allowing for random ‘field trips’ to the martian surface, while the permanent colony is simply established ‘next’ to Mars.

  8. I’m guessing that the first ten closed-system ecological screw-ups are likely to be lethal in less than six months. With a lunar colony, you’ve got plenty of time to engineer a fix and apply it. On Mars, everybody’s dead before the problem can be solved and the necessary materiel transported.

    I agree that Mars is a much more likely spot for a colony to flourish long-term, with much better sustainability, but you’ve got to develop best practices on the Moon before tackling a permanent settlement on Mars.

  9. Brock says:

    Larry brings up a good point. Being able to get spare air filters or whatever on relatively short notice would make the difference between a succesful effort and the loss of all hands. Assuming SpaceX or others reach the point of multiple launches per day, getting a rescue mission to the Moon on very short notice would be much easier than getting one to Mars. Even more so if there’s a permanent presence in LEO, GEO or the Lagrange points (e.g., satellite service workers stationed in Bigelow modules).

    I’m also not sure the ores issue is a big deal. Before we are building colonies on the Moon or Mars we will need cheap, reliable access to LEO. If we have cheap, reliable access to LEO (e.g., via the Falcon Heavy or (even better) a fully resuable Falcon 9 fleet) then someone will surely be working on mining NEAs for mineral deposits. If you can mine NEAs you can drop 1,000 tons of nickel-iron or whatever you want anywhere on the Moon as easily as bring it back to Earth. Getting the ore to Mars though would be easy or hard depending on its orbit.

    Here’s my primary objection to making grand plans for colonizing either the Moon or Mars though — we don’t know what the minimum gravity dose is for long term health and successful reproduction. We just don’t. The idea that 0.38 g is better than 0.17 g is pure speculation. Maybe they’re both fine. Maybe they’re both wildly insufficient. We just don’t know. At this time the only thing I’m pretty sure would work is two Bigelow modules separated by a tether and spinning around an axis point (call it the Mark I O’Neil Station).

    Assuming though there’s some variation in the amount of g we need long term, we also shouldn’t overlook Venus. Yes, the surface sucks, but the gravity is .9 g and the atmosphere at 50 — 60km is nearly the same as Earth. 1 bar and 0–50 degrees C (downright Mediterranean by solar system standards). If we have LEO, we have the NEAs. Local materials aren’t a problem. You could build a hollow tensegrity sphere in orbit, fill it with N/O (a lifting gas) and de-orbit slowly. Solar power would be abundant, and the atmosphere outside would alleviate the need for pressure suits on EVA. It’d be tricky, I admit, but I’m continually surprised more people don’t at least mention it as an option.

    Click the url at my name for the Wikipedia article arguing the benefits of this approach.

  10. Jim S. says:

    I think the biggest problem with going to Mars en masse before going to the Moon en masse is psychological. The Moon is right there, we see it almost every day, it would be a potential destination for us personally. Mars would be a dot in the sky indistinguishable from all the other dots, and it would take a year to get there and a year to get back.

    I’m not arguing against you, I’m just cynical of convincing others of the case for Mars.

  11. Tcobb says:

    An essential problem regarding any trans-terrestrial colony is how to provide living space which is protected. It might not be practical, but one of the things I have often pondered is using nukes to provide cover on the moon and Mars.

    On earth the results of underground nuclear explosions produced huge glass lined domes deep within the earth. And depending upon the type of bomb used, radiation levels in the domes did become acceptable for humans within fairly small time frames. Much less radiation than you would get on the surface of the moon or Mars.

    Drill down, set off a nuke, plug it and then fill it with water, nitrogen, and carbon dioxide. Create a light source in the dome and put some primitive plants down. As I recall ferns and mugworts thrived in lunar soil. Once they grow chop them up into compost and start planting things like wheat. The oxygen level will rise, and ultimately you have a protected environment deep underground that humans can live in.

    Its just a thought…

  12. Brock says:


    There are caves on the Moon already which are quite large, and protected from the lunar “weather”. You’d just need to level and grade, which wouldn’t require nukes.

  13. The highly abrasive qualities of the uneroded lunar dust is well known. On Mars the windblown dust particles are as small as one to two microns in diameter, much finer than dust here on the earth. Dust particles that small, well they are bound to get into everything. As PEL (project element lead) for the RAT (Rock Abrasion Tool) on the MER rovers, I was very concerned about the seals on the RAT; in addition to the aeolian material the abraded rock material adjacent to the RAT is so fine it islike smoke and no seals we could devise were going to long keep such dust from penetrating into the RAT drive train. It is true the rovers and their payload were well built and anyone involved is proud of their robust performance but we were lucky as well. The mission success criteria for the RATs were one successful deployment on each rover. We have now had over 150 successful deployments (and millions of motor revs) of the RATs on Mars without any significant degradation of the drive trains. The dust on Mars does not appear to be abrasive.
    For more information see .

  14. JohnHunt says:

    Wow! Great discussion. Very productive. Everyone’s bringing a helpful perspective that none of us have individually.

    > I agree with you that cost should ultimately be the deciding factor on where to settle first…

    I think that’s great. I’d much rather be having a technical argument that a philosophical one.

    Transportation costs will be significant but so will development costs for this new venture. I am looking at using only Falcon 9 and Heavies so as to keep the transportation costs as low as possible. When sending people, transportation costs to Mars will be greater than to the Moon. For equipment, Mars has aerobraking but also a deeper gravity well. For heavy equipment I think you’d have to take on. quite a bit of storable propellant for which the rocket equation will punish you. Don’t forget if you are digging down then you’ll have to pull all that regolith out.

    > robots can be programmed to handle expected problems…

    You may have forgotten we’re talking TELErobots here. They would have the same intelligent response to the unexpected as their human drivers. And if working with other robots, if one gets stuck, the others pull it out. And there’s no 8–30 minute response lag but only 3 seconds.

    I only know about CO2 on Mars and methane and CO on the Moon.

    It is true that there are fewer ore bodies on the Moon than Mars but not like Earth. But an MSSC isn’t the same thing as an industrial civilization. We have minimalist needs. The following is a good write-up of what is possible on the Moon:

    I know little about industrial construction. What I would wonder is if an igloo of sandbagged regolith over a Bigelow Teflon inflatable habitat would provide enough pressure and protection or if digging/blasting into the side of a hill could result in a naturally covered cave that may or may not need internal supports but would provide the 5 meters of covering needed for cosmic ray protection.

  15. Tcobb says:

    You have maps of these caves? Where can I find them? And will they hold air?

  16. GaryChurch says:

    ” It may also help reduce the danger of galactic cosmic rays, but that will need to be tested.”

    No, it does not stop any to make a difference.

    Mars is the worst place to go. A deep gravity well to climb in and out of. A case of too much gravity and no protection from radiation.

    Ceres is a much better deal. A multi-year mission is a multi-year mission and if you are going to Mars it makes more sense to go farther to Ceres. No problem landing as it has very little gravity, but may have liquid oceans. Solar resources on Mars are not very good.

    The Moon has ice and is the first place to go for the simple reason that any human missions outbound will require massive shielding and that shielding will require nuclear propulsion.

    Building and lighting off a nuclear spaceship in earth orbit is not acceptable and bringing up all that water is problematic. The moon has water for shielding and no restrictions on nuclear activities.

    The safest way to transport fissionables to lunar orbit is a direct launch of a human-rated HLV with an escape tower and the material packaged in a capsule.
    My essays on Lifeboat also talk about nuclear excavation if anyone is interested.

  17. JohnHunt says:

    I would design a lunar development plan where a previous lander would already have fuel ready in case an emergency return were necessary. Also, spare equipment and parts would be delivered before humans return do that an emergency shipment probably wouldn’t be needed and so that the common lander would have more risk retired.

    > Before we are building colonies on the Moon or Mars we will need cheap, reliable access to LEO

    It depends upon what you mean by cheap. If SpaceX can sell us a Falcon Heavy for $125 million, that’s cheap enough for me. Reusability would be great but not critical in my view. We could establish an MSSC for about $10 billion. We dare not wait very long to secure the human species.

    Brock, you are completely right about out not knowing the difference between 17% and 38% gravity. Yes, tethered can give you 1g. But then you just removed yourself from easy regolith shielding and human-tended water mining and/or added a significant transportation cost (Moon to orbiting hab). IF 17% gravity with exercise and Fosamax isn’t enough then perhaps a centrifuge is workable.

    Tcobb, Gary Church advocates using a nuke to create a large underground chamber then remove radioactive rubble telerobotically. I’m not sure how practical it is but it is certainly bold.

    There are caves on the Moon. I just don’t know if they contain much ice or of they can be found near a peak of eternal light.

  18. The best solution for colonies is a “Sleeper Train.” A circular tunnel with a circular train that accomplishes the same thing as a tether except underground. The colonists spend the workday bouncing around in hypogravity and the other other half small apartment living in 1G. This works on low gravity bodies of which there about a hundred in the solar system big enough to anchor large colonies.

  19. flashgordon says:

    Looks like everybody is seeing what I’m seeing in SpaceX. I just started checking them out a lot more like two days ago! I generaly monitor the nanotech front(and quantum computers), and not necessarily the space tourism/private space industry.

    Chinese space rocketry people have already said that SpaceX is way better than what they can do anytime soon!

    With SpaceX, we can do both the Moon and Mars and make the Moon help out Mars(and Ceres and other asteroids/comets).

    I’m just so excited about SpaceX the last two days! They will make private space business happen(and make lunar economy happen — either solar power, nuclear helium mining and much else probably). In terms of the Mars/Moon debate, SpaceX can allow for a lunar water and rocket refuel to make the Mars missions even cheaper! We don’t need to make a full scale lunar base first and then go to Mars; just go for the water and rocket fuel.

    In perhaps near enough time, SpaceX can make much better rockets than they currently are capable of using. Recently, Zyvex has built a Piranna boat out of nanotubes. It’s performance is untouchable because of the lighter weight and still far stronger than any other material. If they can make that; why not a rocket of their current innovative designs with nanotube construction? I’ve already tried to e-mail them about it. They do that combining of technological ability, the costs and ability will shoot even further up!

    With nanotube technology of Zyvex, we can provide shelter on the moon and mars!

  20. flashgordon says:

    I should stress the SpaceX making a lunar colony practical a little more. It can make for the economic growth which would allow for more mars supplies that can be used for repairs on mars. What SpaceX has done is huge.

  21. flashgordon says:

    The moon could be advantageous using reusable SpaceX technology because we could just station a space station in orbit. The space station would have both food and manufacturing modules. We could go up and down a low gravity well of the moon; mine it for resources(we could go to mars and mine the martian asteroid moons also!). The space station would also have either tethers(probably at first), or 2001 cylinders for artificial gravity. Just with reusable cheap rockets allows us to live on space stations instead of trying to live on the surface of these worlds. Hence, the moon, and asteroids are better places to be than Mars!

  22. Astro says:

    A well written article, and you make some good points. The main problem is the idea of using current technology to get to (and from) Mars. It’s a non-starter. We need to develop a technology where we can maintain a constant (small, like only 0.1 g) acceleration of the spacecraft to get there. That can cut the travel time to a mere 21 days during Mars’ opposition. Mid-flight refueling may be needed; but 21 days nearly eliminates the issues of solar flares, long-term weightlessness and spacecraft reliability.
    ON A different subject: Your website design needs some work. Reading white letters on a black background is very hard on the eyes. Waay too much contrast. Make the background a charcoal gray and the readability will vastly improve.

  23. Thucydides says:

    What is the alternative to Mars or the Moon? NEO’s.

    Near Earth Objects are energetically closer than even the Moon, have water and usable materials for building and life support, and can be turned into long term space stations.

    Virtually all the objections of the Moon and Mars can be answered, energy is easily available and even gravity can be “tweaked” by adjusting the rotation of the NEO.

    Frankly a true space civilization needs to be founded in space, not the planets.

  24. Everybody wants to get back to the cheap access to LEO, but this is a classic catch-22 problem. Without a place to go, the economy of scale necessary to bring launch costs down will not develop, and without lower launch costs, there will be no place to go to drive the higher launch rates. My idea is to simply kick start the whole process by minimizing the cost of the initial push into space. A few people have brought up alternatives for habitat construction, and that is what I am researching. Imagine a cement factory that can be carried on a single Falcon Heavy flight, allowing the construction of multiple habitats with local materials. Another Falcon Heavy flight to carry all of the equipment needed for electrolytic metal extraction, and you have most of the industrial capacity needed for an advance party of colonists to begin construction. The issue of resupply came up, and that is why it needs to be as self sufficient as possible from the start. Realistically, just how far away is the Moon when you consider launch preparation into the picture? It is much more than three days, and could easily be months when you consider the time to prepare a launch and hope everything works right.

    All of the big mega projects like a circular train for gravity and carving out asteroids sounds great, and may be possible after, and only after a significant industrial infrastructure is established out there. Mars is not the only option out there, but I think that it may hold the best hope for an early start to colonizing space.

    I would also like to see some more research done on the caves found on Mars. They may be more practical than my “Anthill” habitat that I am working on, and they can be sealed using the same cement I am researching. This stuff sticks to just about anything and would be perfect for walling off a cave entrance.

    Steven, thanks for confirming my suspicions about Martian dust. It sounds like it can’t be much worse than the dust we dealt with in Iraq and Afghanistan. It was a thick layer of fine powder that got everywhere, but it was manageable with some basic housekeeping.

    I know everyone has different ideas about how to best colonize space. Nobody will know for certain what works until somebody tries it, and we need to start somewhere. It will be difficult and dangerous, and the first colonists will suffer a lot of hardship. Some of them will probably die trying to establish a colony. If we are not willing to take those risks and accept these hardships, then we may as well just stop this discussion and go back to watching American Idol while we wait for our inevitable extinction.

  25. flashgordon says:

    No, we’ll just go in a dark ages for awhile.

  26. flashgordon says:

    Your arguements are not much more than what Robert Zubrin has written already; a plan that no government seems willing to fund.

    I’m not overly worried; seems to me that nanomanufacturing will come about sooner than later; prices will drop.

  27. GaryChurch says:

    then we may as well just stop this discussion and go back to watching American Idol while we wait for our inevitable extinction.

    check out comment 17 Brandon…ve-prizes/

  28. Stuart Eves says:

    Suggest that further unmanned missions are justified first to determine the origin of the methane in Mars’ atmosphere. If it were to be established that it was a result of biological activity, the planetary protection considerations might need to feature more prominently.

  29. Jay says:

    Thanks all for this very interesting and inspiring thread.

    1) The threat of extinquishing ourselves is rather closer than we are ought to believe:
    The amount of spent fuel rods in the Fukushima Daiichi reactor #4 that gets fully exposed to the elements when the building would collapse — by e.g. another earthquake — will have an enourmous impact on the ‘livability’ of our planet
    2) You all state there are enourmous risks when we would start our first MMSC attemps, yet without any doubt tonnes of people are willing to take the opportunity to part with Earth life and go on this adventure, and to really contribute to the development of mankind.
    3) Excellent idea of considering Venus as another option for colonization. At 50 km in the atmosphere, we are at 88% g, at a 1 bar atmospheric pressure and a reasonable temperature (75°C). Summing this up, sounds like paradise compared to even Mars.
    I reckon that we can easily capture Sulfuric Acid from the atmoshpere and use the hydrogen proceeds to produce water.

    My 2 cents — hope this thread will revive.