The Heat Flow and Physical Properties Package (HP3) will make in-situ measurements
        of the heat flow on Mars. The package includes a "mole", which will hammer itself into the 
        subsurface for up to 5 meters. The mole is attached to a tether that contains temperature
        sensors to determine the thermal gradiant. The mole is also equipped with heating foils, 
        which will be used to determine the thermal conductivity of the regolith.