He3 is a fuel that can be used for aneutronic nuclear fusion -- a type of nuclear fusion with far less of a radioactive flux putting less demands on the wall ma

He3 is a fuel that can be used for aneutronic nuclear fusion -- a type of nuclear fusion with far less of a radioactive flux putting less demands on the wall material. The moon is one of the only sources (apart from the solar wind). Which is not to say that it's a good idea, just that, were small fusion power-plants (for military applications, for example) ever achieved technologically, it may quite possibly require aneutronic fusion, and that a fuel source would start to really matter.