I think nanotechnology is another reason why we should establishing a space frontier. If Prince Charles is in favor of promoting a space, then I wouldn't hold it against him that he is too cautious regarding nanotech. If the Prince opposes space development and nanotech, then I think this means he must provide some other viable long term solution- or simply shutup.
With nantech developed in an isolated environment, the unlikely chance of major accidents are avoidable, and nano defensive solutions could be developed to prevent deliberate "terrorist" type of attack. Space could also be environment which might also be favorable to nanotech development and production.