InSight's HP3 probe is meant to drill deep into Martian soil. And the depth of reach is determined by whether there is a rocky layer underneath or not. If it's loose soil all the way down, merrier it will be. But, if the mole hits a rocky surface, can the probe retract the tether, and let the robotic arm reposition the probe to a new place?
Or in case of a uniform regolith condition, can the HP3 instrument be repositioned in multiple places to assess the homogeneity of the soil?