1. McDonnell Center for the Space Sciences, Department of Earth and Planetary Sciences; Washington University in St. Louis; St. Louis Missouri 63130
2. Robotic Mobility Group; Massachusetts Institute of Technology; Cambridge Massachusetts 02139
3. California Institute of Technology/ Jet Propulsion Laboratory; Pasadena California 91011
4. Division of Geological and Planetary Sciences; California Institute of Technology; Pasadena California 91125
5. Department of Earth and Planetary Sciences; University of California at Santa Cruz; Santa Cruz California 91125