Firstly, this isn't the first time Amun 3554 mining has come up [1].<p>Look, I'm a sci-fi fan like so many other HNers but the economic reality just doesn't add up.<p>Amun 3554 has a highly eccentric orbit [2], even though it does cross Earth's orbit. JPL has data [3].<p>You need to consider that:<p>1. It's expensive to get into orbit. Even at SpaceX's prices, you're talking ~$1000/kg for LEO insertion;<p>2. You need to get equipment to the asteroid;<p>3. You need to get to the asteroid. Proximity to Earth isn't the problem here. The problem is the delta-V required to match velocities;<p>4. You either need to bring back the entire asteroid, which would require a massive amount of delta-V, or you need to mine the asteroid, which would take a massive amount of equipment;<p>5. If you get raw materials back to Earth orbit, depending on the application, you may then need to get them back to Earth, which granted is significantly easier than escaping Earth's gravity; and<p>6. If you get a massive quantity of some valuable material it'll change the economics. That $20 trillion won't be $20 trillion with the added supply.<p>I am assuming this would be an automated operation as the cost of manned spaceflight is significantly higher and automated systems should hopefully improve in the intervening years.<p>Now, compare this to some other materials we have on Earth. Iron is pretty abundant (both on Earth and in the universe, due to it's energy relationship with fusion). On Earth, we dig up iron for under $30/ton and can ship it anywhere on Earth for another $50-100/ton (IIRC).<p>For the cost of a single SpaceX launch you'd need to bring back about a million tons of iron to be on the same scale.<p>Obviously that's why they're targeting much more valuable materials like platinum but I hope that puts things in perspective.<p>Our society is built on cheap and plentiful resources (fossil fuels, metals and minerals). As abundant as they might be in space, increasing the cost of iron 1000 times is going to have profound implications for our entire species. At some point of course recycling makes more economic sense but that's just a temporary cushion (eg you lose materials through corrosion).<p>I believe we're coming to a resources-crunch within the next 100-200 years that will result--one way or another--in a massive drop in population and a fundamental change in our society. Let's just hope we survive it.<p>As much as I'd wish otherwise I have a hard time envisioning space mining or even prolonged living in space as being economically viable in any way, shape or form.<p>[1]: <a href="http://money.cnn.com/2006/02/27/technology/business2_guidetospaceintro/index.htm?cnn=yes" rel="nofollow">http://money.cnn.com/2006/02/27/technology/business2_guideto...</a><p>[2]: <a href="http://en.wikipedia.org/wiki/3554_Amun" rel="nofollow">http://en.wikipedia.org/wiki/3554_Amun</a><p>[3]: <a href="http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3554+Amun" rel="nofollow">http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3554+Amun</a>