This study evaluated the effect of water saturation on the behavior of porous rock during mechanical excavation, such as drilling. Such understanding will increase the ability to design robust and flexible tools for drilling in liquid-water aquifers in the martian shallow crust. This capability will be crucial to sustaining the exploration of Mars, and ultimately of other places where liquid water occurs near the surface. The experiment controlled speed of indentation of the rock (by an indenter of a typical shape for drill bits), and the state of saturation of the rock samples. The indentation speeds were expected to bracket the threshold between drained and undrained conditions. Specific energy of indentation increased with saturation during high-speed indentation, but no other experimental parameters gave clear results. Further tests are needed.