The third crew rotation of the Mars Desert Research Station has begun. The rotation, which started March 10, will run through March 24. During this time, the crew will continue the MDRS’s program of sustained field exploration of the Utah desert while operating under many of the same constraints that a human crew would in an expedition to Mars. The purpose of this work is to learn how to explore better on the Red Planet. The commander of the third rotation is Dr. Bjoern Grieger, of the Max Planck Institute for Aeronomy, Katlenburg-Lindau. Dr. Grieger has a background in physics, astronomy, and paleoclimatology and has had cosmonaut training in Star City. Nell Beadle, a professional field geologist with Fugro Seafloor Surveys, Seattle, Washington, will serve as chief geologist for the crew.