Because the Earth gets hotter the deeper you drill, EGS could expand the reach of geothermal power enormously and provide access to a virtually inexhaustible energy resource.
With each new well, new tools are being developed to deal with the intense pressures and temperatures involved with controlling a drill bit that is 6 miles into the earth.
ExoMars, as we call it on this side of the pond, envisages a satellite to study the Martian atmosphere, followed by a large robotic rover to drill beneath the surface and cache rocks for later return to Earth.