McFadden, W.J. Merline, J.K. Miller, W.M. Owen, Jr., C. Peterson, L. Prockter, J. Warren, D. Wellnitz, B.G. Williams, and D.K. Yeomans, “NEAR at Eros: Imaging and Spectral Results,” Science 289: 2088-2097, 2000.

41. J.I. Trombka, S.W. Squyres, J. Brückner, W.V. Boynton, R.C. Reedy, T.J. McCoy, P. Gorenstein, L.G. Evans, J.R. Arnold, R.D. Starr, L.R. Nittler, M.E. Murphy, I. Mikheeva, R.L. McNutt, Jr., T.P. McClanahan, E. McCartney, J.O. Goldsten, R.E. Gold, S.R. Floyd, P.E. Clark, T.H. Burbine, J.S. Bhangoo, S.H. Bailey, and M. Petaev, “The Elemental Composition of Asteroid 433 Eros: Results from the NEAR-Shoemaker X-ray Spectrometer,” Science 289: 2101-2105, 2000.

42. R.P. Binzel, A.W. Harris, S.J. Bus, and T.H. Burbine, “Spectral Properties of Near-Earth Objects: Palomar and IRTF Results for 48 Objects Including Spacecraft Targets (9969) Braille and (10302) 1989 ML,” Icarus 151: 139-149, 2001.

43. B.J. Buratti, D.T. Britt, L.A. Soderblom, M.D. Hicks, D.C. Boice, R.H. Brown, R. Meier, R.M. Nelson, J. Oberst, T.C. Owen, A.S. Rivkin, B.R. Sandel, S.A. Stern, N. Thomas, and R.V. Yelle, “9969 Braille: Deep Space 1 Infrared Spectroscopy, Geometric Albedo, and Classification,” Icarus 167: 129-135, 2004.

44. D.C. Boice, L.A. Soderblom, D.T. Britt, R.H. Brown, B.R. Sandel, R.V. Yelle, B.J. Buratti, M.D. Hicks, R.M. Nelson, M.D. Rayman, J. Oberst, and N. Thomas, “The Deep Space 1 Encounter with Comet 19P/Borrelly,” Earth, Moon, and Planets 89: 301-324, 2002.

45. For a more complete description of touch-and-go sampling see, for example, Space Studies Board, National Research Council, A Scientific Rationale for Mobility in Planetary Environments, National Academy Press, Washington, D.C., 1999, p. 37.

46. A.S. Rivkin, Observations of Main-belt Asteroids in the 3-Micron Region, Ph.D. Thesis, University of Arizona, 1997.

47. A. Coradini, F. Capaccioni, P. Drossart, A. Semery, G. Arnold, U. Schade, F. Angrilli, M.A. Barucci, G. Bellucci, G. Bianchini, J.P. Bibring, A. Blanco, M. Blecka, D. Bockelee-Morvan, R. Bonsignori, M. Bouye, E. Bussoletti, M.T. Capria, R. Carlson, U. Carsenty, P. Cerroni, L. Colangeli, M. Combes, M. Combi, J. Crovisier, M. Dami, M.C. DeSanctis, A.M. DiLellis, E. Dotto, T. Encrenaz, E. Epifani, S. Erard, S. Espinasse, A. Fave, C. Federico, U. Fink, S. Fonti, V. Formisano, Y. Hello, H. Hirsch, G. Huntzinger, R. Knoll, D. Kouach, W.H. Ip, P. Irwin, J. Kachlicki, Y. Langevin, G. Magni, T. McCord, V. Mennella, H. Michaelis, G. Mondello, S. Mottola, G. Neukum, V. Orofino, R. Orosei, P. Palumbo, G. Peter, B. Pforte, G. Piccioni, J.M. Reess, E. Ress, B. Saggin, B. Schmitt, D. Stefanovitch, A. Stern, F. Taylor, D. Tiphene, and G. Tozzi, “Virtis: An Imaging Spectrometer for the Rosetta Mission,” Planetary and Space Science 46: 1291-1304, 1998.

48. National Research Council, New Frontiers in the Solar System: An Integrated Exploration Strategy, The National Academies Press, Washington, D.C., 2003, pp. 31-32, 115, 136, 145, and 206-207.

49. D.P. Cruikshank and C.M. Dalle Ore, “Spectral Models of Kuiper Belt Objects and Centaurs,” Earth, Moon, and Planets 92: 313-330, 2003.

50. W.M. Grundy and J.A. Stansberry, “Mixing Models, Colors and Thermal Emissions,” Earth, Moon, and Planets 92: 331-336, 2003.

51. National Research Council, New Frontiers in the Solar System: An Integrated Exploration Strategy, The National Academies Press, Washington, D.C., 2003, pp. 206-207.

52. National Research Council, New Frontiers in the Solar System: An Integrated Exploration Strategy, The National Academies Press, Washington, D.C., 2003, p. 195.