1. Southwest Research Institute, 1050 Walnut Street Suite 300, Boulder, Colorado 80302 U.S.A.
2. Sandia National Laboratories, 1515 Eubank SE, MS 0404, Albuquerque, New Mexico 87123 U.S.A., dbowma@sandia.gov
3. Department of Geological Sciences, The University of North Carolina at Chapel Hill, 104 South Road, Mitchell Hall, Campus Box #3315, Chapel Hill, North Carolina 27599 U.S.A.
4. Colorado Center for Astrodynamics Research, University of Colorado Boulder, ECNT 320, 431 UCB, Boulder, Colorado 80309 U.S.A.
5. Now at Syncroness, Inc., 10875 Dover Street, Westminster, Colorado 80021 U.S.A.