A UK led team is developing a key science instrument for the 2011 ExoMars mission. The European built and financed probe will deliver a highly complex rover to the surface, equipped with a drill to delve deep beneath the Martian surface. Samples will then be transferred to the "Pasteur Laboratory" aboard the rover. One of the key devices in the lab will be the Life Marker Chip (LMC) which will test soil samples for specific molecules that can be associated with life. Essentially, the test is a "lock and key" procedure, in that certain molecules associated with life will only bind with other molecules of a particular shape. If one of the target molecules is present, it will bind to a prepared receptor in the experiment. The
BBC has a detailed piece on the science of the mission.