Billy T, Once again we have been over this before, your argument is fallacious. A materially self sustaining asteroid mine be it fully automated or a manned colony would be profitable because the earth would not need to send up any supplies. Once you send up the mining equipment and crew, it continues to return materials virtually indefinitely. Imagine had the European empires tried to utilize America like we utilize space. Instead of sending indentured servants, slaves and conquistadors to pillage and rape the land, then sent ships with all the supplies it would need for the way there and back and the people would not stay their but travel back in rotations. We would still be exploring the Americas to this day! In short until we undertake one-way trips into space, space will remain uneconomical. Mind you already one-way trips is quite economical for the unmanned spacecraft we send up, its only a matter of time until we can make them competent enough to create self-replicating asteroid mines.