High Frontier can help Mars Direct

>>>Which ones were you thinking of here?>>> Manganese, Copper, Germanium,
Arsenic, Gold, Silver, Lithium, Beryllium, Strontium, to name just a few. Of
course you are correct, these substances may be concentrated locally, within
meteorite craters, but we cannot simply assume that they do exist. Assuming that
there are no such local concentrations, we are going to need to find a
supplementary source of these materials. The obvious source would be a near
earth asteroid.