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NASA Space Science

The Best Near-Term Future of Space Exploration? 444

An anonymous reader writes "Much fanfare has been made about manned missions to moons and planets, but little has been done about travel to the asteroids — until now. NASA is working on plans for a trip to the asteroids by 2025. This type of mission has great potential for positive economic return based on the fact that no effort has to be spent on getting in and out of a distant planet's gravity well. Yes, we should go to the planets, but we should master mining the asteroid belt for resources first because it is easiest. What do you think?"
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The Best Near-Term Future of Space Exploration?

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  • Re:Priorities (Score:3, Informative)

    by mangu ( 126918 ) on Monday August 30, 2010 @08:45PM (#33421950)

    First we have to ask ourselves, how many people can our planet sustain? 10 billion? 15 billion?

    We don't know for sure.

    Then we have to ask, how long before we reach that many? 100 years? 200 years?

    We don't know for sure.

    Then we have to ask, what resource is going to run out first? Drinking water? Food? Air?

    We don't know for sure.

    When we have those answers, we will be able to discuss which is best to spend money and effort on, mining the asteroid field or getting off this damn rock.

    This we know for sure: unless we do serious research we will never get the answer to any important question. And unless we are ready to research many different alternatives we will never be sure of our answers.

    I think we should consider all possibilities and chose which one has the better probability of success. Exploring the asteroids seems to offer some interesting possibilities. At least there's an intrinsic advantage in getting resources from them, compared to any planet or moon in the solar system, given the different gravity wells.

  • Re:Welcome to Earth (Score:2, Informative)

    by orangepeel ( 114557 ) on Monday August 30, 2010 @08:46PM (#33421958)
    If you're trying to make me feel better:

    1) Thank you.
    2) It's not working. :-(
  • Re:Economic sense? (Score:2, Informative)

    by shoehornjob ( 1632387 ) on Monday August 30, 2010 @09:22PM (#33422228)

    You forge the gold into a landing module and use a mass-accelerate to bring it back to earth.

    Gold lander module meets atmosphere at oh 18 thousand mph http://en.wikipedia.org/wiki/Space_Shuttle#Re-entry_and_landing [wikipedia.org] and said lander becomes gold soup. At this point your profit is pretty much fucked but you've got a really nice gold streak in the sky.

  • Re:Why mining? (Score:5, Informative)

    by CheshireCatCO ( 185193 ) on Monday August 30, 2010 @09:38PM (#33422322) Homepage

    In fact, everything that we currently mine (copper, iron, zinc, platinum, gold, etc.) came from asteroid impacts.

    Only in the sense that Earth is basically built of asteroids in the first place. But in that limit, you're just advocating mining on Earth again, the nearest and most habitable such body.

    all those elements moved to the core, leaving only things like calcium and silicon and carbon in the Earth's crust when it cooled. All the useful elements came from asteroid impacts after that.

    Good lord, no. Certainly elements did tend to head to the core preferentially. Such siderophilic (iron-loving) elements are fairly rare in the Earth's upper layers. Others are still fairly common. Or at least common enough. Even iron, which lead the charge to the core during differentiation, is awfully common in the crust.

    In fact, silicon (the second most abundant element in the crust) is only about ten times more common than iron, which is about as abundant as calcium (which you cite as being abundant). Aluminum is more abundant than calcium and is in fact only a few times less abundant than silicon. (Oxygen, incidentally, is the most common element in the crust, beating silicon out by a factor of a few.) In fact, most metals we're particularly attached to are about one-in-ten-thousandth as common as silicon. If you factor in the fact that they're usually found in clumps, that's a very cheerful thought.

    (For the record [wikimedia.org].)

    By the way, if your theory of asteroid delivery were true, I'm pretty sure we wouldn't have very much metals to work with. The Earth's crust is tectonically recycled every several hundred million years (any given chunk has been subducted and recycled several times, more or less; we estimated this my first year of grad school, but I forget the numbers exactly), so you could only rely on the metals delivered in the past few hundred million years. Asteroid impacts are getting rarer all the time, especially big ones.

    Also, recall that a given asteroid is as likely as much rock as metal. In fact, Earth is more metal per mass than the average asteroid. (A lot of our silicates ended up in the Moon instead.) However, some asteroids are definitely mostly metallic and for mining purposes, that's a mad bonus. (For metals raining down from heaven, however, you have to factor in the fraction of the asteroids that isn't metal.)

    Also, you're not factoring in the costs of bringing metals back to the Earth (if that's your goal). It's far more expensive to do that than to mine them here and will be for the foreseeable future. Of course, if your goal is to use them in space anyway, then it might be better to mine them there. (On the other hand, then you have to build the refining and construction infrastructure in space, which has a lot of challenges of its own.)

  • Re:Priorities (Score:3, Informative)

    by MaWeiTao ( 908546 ) on Monday August 30, 2010 @11:38PM (#33423084)

    If you think we've got population problems you clearly haven't been paying attention. East Asia, which has some of the highest population densities in the world also has among the lowest birth rates. The rate for China is lower than the US. Nations like Japan, South Korea and Taiwan have among the lowest rates in the world. Most of Europe also has extremely low birth rates. If it weren't for immigration America's rate would probably be a lot lower than it is. I don't know if Europe still does it, but Japan's and Taiwan's governments have offered incentives to people who have children. What's the problem? If the trend continues they'll suffer dramatically in terms of talent and labor. And more importantly for governments they wont have enough people to help sustain social programs.

    Fears of population explosions have so far proven to be unfounded. The nations which have the highest birthrates, namely African nations and South Asia also have high death rates. And there is the capability to sustain many more people on Earth than we have now. Despotic leaders, environmental issues and wars are the real problems facing more heavily populated nations.

  • Re:Why mining? (Score:3, Informative)

    by Dalambertian ( 963810 ) on Tuesday August 31, 2010 @02:20AM (#33423762)
    The radiation problem is a big one, and I think the public doesn't yet realize how big of a problem it is. I mean, flight attendants and pilots are exposed to about as much or more than someone working in a nuclear power plant, so shouldn't they be wearing radiation badges? http://iopscience.iop.org/0952-4746/21/1/003 [iop.org] Now fast forward 50 yrs, with asteroid mining profits starting to take off. Will similar health risks get swept under the rug?
  • Re:Belters! (Score:4, Informative)

    by Patch86 ( 1465427 ) on Tuesday August 31, 2010 @03:06AM (#33423898)

    For one, how do you get a rocket with "significant mass" anywhere? We have enough difficulty getting modules the size of a family car into space, I dread to think how we would significantly increase that. And if you can move a rocket around which is as massive as the asteroids, surely you will have already solved the problem in some way?

    For two, I'm inherently nervous about slinging asteroids at Earth with an intention for them to touch down, or enter a steady orbit. Makes you wonder exactly what the dinosaurs were up to in the weeks preceding their unfortunate incident...

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