The Phoenix Mars Lander carries six science instruments. One is a robotic arm made of aluminum and titanium built by NASA's Jet Propulsion Laboratory. The nearly 8-foot-long arm is critical to the lander's operations. On the arm's end is a scoop that looks like a shovel. It is designed to dig trenches, scoop up soil and water-ice samples and deliver the samples to two other instruments on the lander, to be cooked in a mini-oven and tested for chemical properties in a wet-chemistry laboratory and under optical and atomic force miscroscopes.

Because the arm will be making direct contact with icy soil that is conceivably a habitat where microbes could survive, extra precaution has been taken with it to prevent introducing life from Earth. Before the arm was given a sterilizing heat treatment in March 2007, it was enclosed in a biological barrier wrap.

Source: University of Arizona