That is a very interesting article wright. I was kind of skeptical as to the economic feasibility of asteroid mining, but an estimated $20 trillion payday would definitely be enough to offset the costs of building the robotic probes, as well as the launch and other costs such as refining the ore once it is returned to Earth. It will be interesting to see if Planetary Resources could pull it off. I do think the concept of mining asteroids and other planetary bodies does pose some unique challenges though, mainly in the realms of claims and competition. That may be a discussion for another thread though.