The Trump Administration and U.S. Congress are promoting new ventures to extract valuable minerals from outer space. This Article does not dismiss the idea out of hand, but explores reasons for caution, including practical problems with space mining, its environmental impact, the likelihood that the United States could violate international law, and the risk of armed conflict. These problems are exacerbated by financial conflicts of interest in our government with a handful of billionaires, who have a financial interest in space mining work. The promotion of their agenda could involve wasteful government spending on subsidies for private ventures, with a very uncertain return. Space mining, if it becomes economically feasible, may be inevitable, and this means that it is important to work toward multinational agreements to regulate it rather than assume that enforceable principles of international law will prohibit it.