Promoted from the Ricochet Member Feed by Editors Created with Sketch. Why Mars Instead of the Moon?

 

moon-meetMaybe I am influenced by having read Robert Heinlein’s The Moon is a Harsh Mistress when it was first published, but I am wondering about all the recent PR for a manned mission to Mars — even by some people who are not named Robert Zubrin — and whether it is just the romance of going to another planet. The Moon seems to make much more sense for a first permanent base (i.e. not an orbital space station) for a number of reasons:

  1. It’s closer.
  2. There is micro-gravity.
  3. If you go underground, you might be in decent shape for protection against high energy particles.
  4. There appears to be water ice in some of the craters.
  5. Mining on the Moon might, or might not, be worth the effort of going there. (Isn’t a useful isotope of Hydrogen available on the Moon and not on Earth?)
  6. The Moon, being out of the deepest part of Earth’s gravity well is, from a propulsion energy perspective, about halfway to anywhere in the inner solar system.

So what are the arguments in favor of Mars and against the Moon, besides “been there, done that?”

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  1. Jean Jacques Ratso Inactive

    It depends on what you need a base for, and — basically (heehaw) — you only need a manned one for PR and inspiration.

    And to misquote Jim Morrison: “We just did the Moon!”

    Mars is more romantic. Neither will probably ever be done with humans. Machines don’t need expensive life support systems or quintuple backups.

    • #1
    • October 10, 2015, at 2:05 PM PDT
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  2. Eric Hines Inactive

    Couple thoughts from a non-scientist, in no particular order. The moon isn’t outside Earth’s gravity well; it’s just moving across the gradient at a speed that keeps it from falling on in or moving on out.

    For colonies, the surface of the moon isn’t optimal; L4 and L5 are. It takes a potful of energy to get back up the Moon’s gravity gradient. Getting colony structures big enough to have a non-dizzying rotation speed to have an area of 1g acceleration for the sake of Earth-type life forms would be better.

    For materials, the moon’s regolith is worth mining, but if we’re going to spend the bucks to do that, we’re better off using mass drivers (solar powered!) to shoot batches of the stuff to refineries/factories (the initial purpose of the colonies, along with science) at those Lagrange points.

    Once we’ve gone as far as the moon, the Earth’s and the Sun’s gravity gradients are such that a significant fraction of the added effort to get to Mars is bound up in just grunting through the time to get there (and associated needs to cart along consumables like food and O2 and protection from solar radiation bursts). Mars’ regolith is worth mining, too, and so are its moons’.

    Mars’ moons, too, have enough mass to solve some early structural engineering problems in building shelters and factories without having so much mass it takes significant energy to leave those surfaces.

    Mars has other attractions: I can enjoy the view from Mons Olympus, and with a suitably large wing, hang glide off it. There’s also a potful of life science/origin of Earth-type life science to be done on Mars that can’t be done on the Moon. Mars appears to have liquid water and does have an abundance of dry ice. Mars has weather that, studied up close, should broaden our understanding of how weather happens.

    He3’s primary use is in fusion power plants. Neither the Moon’s nor Earth’s supply of He3 does us any good for that, though, until we figure out how to do the fusion power plant part.

    Eric Hines

    • #2
    • October 10, 2015, at 2:06 PM PDT
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  3. Cantankerous Homebody Inactive

    I recall one scientist saying that the moon’s dust will jam all our machinery.

    • #3
    • October 10, 2015, at 2:13 PM PDT
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  4. Randy Webster Member

    Are L4 and L5 the Trojan points?

    • #4
    • October 10, 2015, at 2:32 PM PDT
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  5. John Walker Contributor

    Lensman:.So what are the arguments in favor of Mars and against the Moon, besides “been there, done that” ?

    One could discuss this at book length, and indeed a number of books have been written arguing both for the Moon and Mars as the best destination for a permanent settlement. To answer your question about the advantages of Mars, if you’re looking to establish a human settlement as a backup for the Earth, that requires it to be able, after some point, to exist without resupply from the Earth. Biology is largely based upon four elements: carbon, hydrogen, oxygen, and nitrogen, and all four are present on Mars in quantities sufficient to support a large human population. The Moon has essentially no carbon or nitrogen and, apart from possible water ice at the poles, is so dry that if concrete existed on the Moon, lunar colonists would mine it for water. This means that in the near future, until humans have the ability to access resources in asteroids (which is a challenge comparable to going to Mars), a lunar base will have to resupplied with volatiles brought up from the Earth’s deep gravity well at great expense.

    Mars also has a day just slightly longer than the Earth’s, twice the gravity of the Moon, and a thin atmosphere which still protects against micrometeroid impacts. The Moon’s two-week day and night make solar power difficult (unless you pick a very special location near the poles) and creates a challenging thermal environment. We don’t know how humans will function for long durations in the 1/3 gravity of Mars, but it’s a good bet that any problems will be less severe than in the Moon’s 1/6 gravity.

    • #5
    • October 10, 2015, at 2:33 PM PDT
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  6. John Walker Contributor

    Eric Hines: He3′s primary use is in fusion power plants. Neither the Moon’s nor Earth’s supply of He3 does us any good for that, though, until we figure out how to do the fusion power plant part.

    Helium-3 is attractive as a fusion fuel because the two principal fusion reactions involving it are aneutronic: they produce only charged reaction products which can, in theory, be efficiently converted into electricity and do not induce radioactivity in reactor components by neutron activation. Helium-3 is deposited in the lunar regolith from the solar wind, but only at around 2.8 parts per billion, so you would need a massive mining operation to extract enough helium-3 to replace electrical generation capacity on the Earth.

    Also, after 60 years of research, we have not succeeded in creating a stable, above-break-even fusion reaction using the two easiest fuels: deuterium and tritium, and both of the candidate helium-3 reactions are much more difficult to get to go.

    • #6
    • October 10, 2015, at 2:45 PM PDT
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  7. jetstream Inactive

    Isn’t the moon moving further from the earth by 1 foot per year and will eventually leave Earth’s gravitational field?

    • #7
    • October 10, 2015, at 2:50 PM PDT
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  8. Eric Hines Inactive

    Randy Webster:Are L4 and L5 the Trojan points?

    Yes. Sort of. Trojans also are the bodies already present at a system’s L4 and L5 points.

    Eric Hines

    • #8
    • October 10, 2015, at 2:56 PM PDT
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  9. John Walker Contributor

    Lensman: 6. The Moon, being out of Earth’s gravity well, is from a propulsion energy perspective about halfway to anywhere in the inner solar system.

    Actually, as Mr. Heinlein said, when you get to low Earth orbit, from the standpoint of delta-v, you’re halfway to anywhere. It’s climbing out of that 9 km/sec Earth gravity well that’s so difficult. Here is a chart of delta-v for transfers in the solar system (I’ve linked it rather than embedding because it’s so detailed you’ll need to view it in a full window). The chart is not to scale: you need to add up the delta-v numbers along the path from the start to the destination to compare difficulty. The presence of an atmosphere at the destination allows for aerobraking and/or aerocapture, which can reduce delta-v to get there. This is indicated by a red arrow in the chart.

    Note that from an energy standpoint, there’s not that much difference in getting to the Moon, near-Earth asteroids, or Mars: it just takes a lot longer for the asteroid or Mars missions.

    • #9
    • October 10, 2015, at 3:05 PM PDT
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  10. John Walker Contributor

    jetstream:Isn’t the moon moving further from the earth by 1 foot per year and will eventually leave Earth’s gravitational field?

    The Moon is currently receding from the Earth around 3.82±0.07 centimetres per year due to tidal interaction. If you’re 50 years old, the Moon is around two metres farther away than when you were born. I discuss this in Moon Near Perigee, Earth Near Aphelion, where I note that the recession rate depends upon the configuration of continents on the Earth and may be less during ice ages. The mean recession rate over the last 620 million years is 2.17 cm/year, so at this rate it will take 1.4 billion years until the Moon recedes far enough so total solar eclipses will no longer occur. By that time subduction of the oceans into the Earth’s mantle and increase in solar luminosity will have resulted in loss of the Earth’s oceans and the planet becoming uninhabitable to life forms like our own. Once the oceans are lost, tidal braking will be much less and the Moon’s recession will slow down, so the Moon will not escape the Earth’s gravitational sphere of influence before the Sun goes into its red giant phase.

    Our descendants will be elsewhere.

    • #10
    • October 10, 2015, at 3:21 PM PDT
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  11. Bryan G. Stephens Thatcher
    Bryan G. Stephens Joined in the first year of Ricochet Ricochet Charter Member

    I rather like the idea of doing it with space stations. You can move them around and just go get what you want from worlds.

    • #11
    • October 10, 2015, at 3:24 PM PDT
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  12. Basil Fawlty Coolidge
    Basil Fawlty Joined in the first year of Ricochet Ricochet Charter Member

    If we don’t go to Mars, we will never discover the secret of the Martian moons.

    • #12
    • October 10, 2015, at 3:34 PM PDT
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  13. Randy Webster Member

    You meant Barsoom, didn’t you?

    • #13
    • October 10, 2015, at 3:58 PM PDT
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  14. Gary McVey Contributor
    Gary McVey Joined in the first year of Ricochet Ricochet Charter Member

    I can’t fault John’s logic about the relative resources of the Moon and Mars; hell, it’s tough enough disputing John’s logic about anything. But I’d like to put in a good word for the Moon. The obvious: it’s only three days away. We aren’t yet accustomed to long term stays on the “ground” anywhere, however defined. It might not be a crazy idea to try out equipment and techniques before we put nine months of distance between a crew and Earth.

    I’ve never believed in the Arthur C. Clarke moonbase; I’d go for the Russian conception of a well stocked, fully outfitted station in lunar orbit, from which astronauts would take landing “jeeps” down to the surface for extended stays. Those surface outposts near Clavius or Harpalus would be spartan; the showers, fresh food, and big screen TV would be waiting in orbit at the end of each lunar shift of a month or two.

    Then, sure, Mars is where it’s at, the only remotely conceivable alternative home for humans in the foreseeable future.

    • #14
    • October 10, 2015, at 4:44 PM PDT
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  15. Misthiocracy held his nose and Member
    Misthiocracy held his nose and Joined in the first year of Ricochet Ricochet Charter Member

    Because NASA is (arguably) about spectacle, not practicality.

    If there are practical reasons to do something, it will be done by the private sector (barring overregulation).

    You only “need” government to step in when the goal is impractical.

    The US government has been to the moon. There’s no PR value to going there again. Heck, the PR value had already evaporated after Apollo 14.

    • #15
    • October 10, 2015, at 4:55 PM PDT
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  16. Misthiocracy held his nose and Member
    Misthiocracy held his nose and Joined in the first year of Ricochet Ricochet Charter Member

    Gary McVey: Then, sure, Mars is where it’s at, the only remotely conceivable alternative home for humans in the foreseeable future.

    Homo Sapiens Sapiens has been around for somewhere around 200 millenia (give or take).

    How “foreseeably” into the future does one see a genuine need for extra-terrestrial migration?

    • #16
    • October 10, 2015, at 5:00 PM PDT
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  17. John Walker Contributor

    Gary McVey: But I’d like to put in a good word for the Moon. The obvious: it’s only three days away. We aren’t yet accustomed to long term stays on the “ground” anywhere, however defined. It might not be a crazy idea to try out equipment and techniques before we put nine months of distance between a crew and Earth.

    I didn’t mean to say that a Moon base would not be a useful learning experience in living off-planet. As you note, if things go pear-shaped, you’re only three days from home, which means you don’t have to worry about lots of medical or dental problems which can occur on a long duration mission but which would involve only an evacuation to Earth which is less difficult than from the South Pole in mid-winter.

    It’s just that you can’t set up a self-sustaining settlement based entirely on lunar resources. However, a lunar settlement may be able to support itself by exporting water (easily turned into rocket propellant by free solar energy) and regolith for use in building space settlements. I discussed use of lunar resources in a settlement with access to abundant energy in my review of Honor Bound, Honor Born here on 2014-05-10.

    • #17
    • October 10, 2015, at 5:08 PM PDT
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  18. John Walker Contributor

    Misthiocracy: How “foreseeably” into the future does one see a genuine need for extra-terrestrial migration?

    • #18
    • October 10, 2015, at 5:17 PM PDT
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  19. Gary McVey Contributor
    Gary McVey Joined in the first year of Ricochet Ricochet Charter Member

    Misthi, you have a point, and as usual it’s of diamond hardness. But the reason the Moon lost its PR value was essentially political: after the awe of Apollo 11 settled into the suspense of Apollo 13, the public was inundated with press-driven snark and skepticism from the heights of the culture about the value of Apollo. That’s how the public polled, you’re correct, but it was a low and dishonest time. Only a few years later, people wondered “did we create all this just to throw it away?”

    Many of the things that inspire patriotism are spectacle, not practicality. The purpose of NASA was not to crowd out private industry; it was to make space valuable enough for private industry to take over a lot of it, and they have.

    Megan McArdle had a good article in Bloomberg recently. She says a frequent, if not constant flaw of the Left is underestimating the motivational power of money as compared to mere intangibles like pride and prestige. But the reciprocal flaw of the Right is underestimating the real value of pride and prestige. Someone once asked me if I wouldn’t have been just as proud of the Moon landings if they’d been sponsored and branded by Citibank or General Motors (that’s how long ago it was).

    My answer: No.

    How about the flag raising at Iwo? Would it have been so iconic if the flag had been for Boeing or Westinghouse?

    • #19
    • October 10, 2015, at 5:18 PM PDT
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  20. jetstream Inactive

    Westinghouse didn’t have enough divisions. They might have also been short boat thingies. The Left didn’t know that which was all to the positive.

    • #20
    • October 10, 2015, at 5:24 PM PDT
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  21. Eric Hines Inactive

    Misthiocracy: How “foreseeably” into the future does one see a genuine need for extra-terrestrial migration?

    Who knows? And not knowing means we don’t know. Which puts a premium on getting started.

    There are two other reasons, too: because it’s there.

    And

    What joy to see, what joy to win
    So fair a land for his kith and kin,
    Of streams unstained and woods unhewn!
    “Elbow room!” laughed Daniel Boone.

    Eric Hines

    • #21
    • October 10, 2015, at 5:37 PM PDT
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  22. Gary McVey Contributor
    Gary McVey Joined in the first year of Ricochet Ricochet Charter Member

    With joy doused and hope distended,

    All prospect of air long since expended,

    With breath unsated and real water but a dream,

    “What an impetuous death this must seem!”

    • #22
    • October 10, 2015, at 5:56 PM PDT
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  23. Gary McVey Contributor
    Gary McVey Joined in the first year of Ricochet Ricochet Charter Member

    “The Ballad of Los Alamos”, written before the Trinity atomic test, and here dedicated to John Walker:

    “From this crude lab that fired the dud,

    Their necks to Truman’s axe uncurled,

    Here the embattled savants stood

    And fired the flop heard round the world”.

    • #23
    • October 10, 2015, at 6:05 PM PDT
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  24. Bartholomew Xerxes Ogilvie, Jr. Coolidge

    Dan Quayle answered this question a quarter of a century ago:

    Mars is essentially in the same orbit. … Mars is somewhat the same distance from the Sun, which is very important. We have seen pictures where there are canals, we believe, and water. If there is water, that means there is oxygen. If oxygen, that means we can breathe.

    The science is settled.

    • #24
    • October 10, 2015, at 6:05 PM PDT
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  25. Gary McVey Contributor
    Gary McVey Joined in the first year of Ricochet Ricochet Charter Member

    The engineering is not.

    • #25
    • October 10, 2015, at 6:09 PM PDT
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  26. jetstream Inactive

    Bartholomew Xerxes Ogilvie, Jr.:Dan Quayle answered this question a quarter of a century ago:

    The science is settled.

    Why go all the way to Mars? Obama has alerted us to the existence of 57 states. We still have seven more states to discover right here at home. We’ve got a lot on our plate.

    • #26
    • October 10, 2015, at 6:13 PM PDT
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  27. Gary McVey Contributor
    Gary McVey Joined in the first year of Ricochet Ricochet Charter Member

    dm031

    “But I just read Kim Strassel in the WSJ. She says there’s no market potential down there!”

    “Shut the hell up. Holding steady. 10000 meters and descending”.

    “Cash flow in the outyears will distort tax planning for major estates!”

    “Holding. 6000 meters”.

    “The federal reserve ratio is tanking. We need to alter the discount rate at once!”

    “We have laser acquisition of the landing zone. Switch FC to LZ yellow”.

    “The engines of capitalist prosperity are damaged by cheap Martian imports”.

    “100 meters. Target red. We have acquisition. Fifty meters. Dust. Twenty meters.

    Ten.”

    • #27
    • October 10, 2015, at 6:24 PM PDT
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  28. Gary McVey Contributor
    Gary McVey Joined in the first year of Ricochet Ricochet Charter Member

    One of the joys of Ricochet is the ability to get really educated people to tolerantly read ones’ mistakes and get them corrected. Okay, sometimes it’s a rough process. you can’t make omelets without breaking heads.

    • #28
    • October 10, 2015, at 6:42 PM PDT
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  29. Ball Diamond Ball Inactive

    We have already claimed the moon for our Imperial units of measure. Now the race is on for Mars!

    • #29
    • October 10, 2015, at 7:46 PM PDT
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  30. Valiuth Member
    Valiuth Joined in the first year of Ricochet Ricochet Charter Member

    I think we need to do quite a lot of work before we start talking permanent residency anywhere. Primarily everyone just assumes that if we can get fuel we will be fine, but humans can’t live off of rocket fuel, and trust me when I say this as a biologist, getting things to grow on minimal and defined media is not an easy task. Our food represents a very complicated system of chemistry and energy conversion. It takes more than just some H2O and sunlight to give you your daily calories. And until we really have some efficient way of growing food in reduced gravity, light, and nutrient content we aren’t staying anywhere for long.

    • #30
    • October 10, 2015, at 8:57 PM PDT
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