NAS experts would like to dig beneath the “layered terrain” which surrounds the north polar cap and appears to have been laid down by the ebb and flow of the ice. Other areas of interest are the beds of large channels which appear to have once been river. Unfortunately, this sort of mission is rugged and the most hazardous to a “soft lander” like those used in Viking. During this mission the necessity for landing safely resulted in the selection of featureless sites. To sample these