DAVID H. DEVORKIN is the co-author of National Geographic's Hubble: Imaging Space and Time. He is senior curator of history of astronomy and the space sciences. DeVorkin's major research interests are in the origins and development of modern astrophysics during the 20th century and the origins and development of the space sciences from the V-2 rocket to the present. He is the author/editor/compiler of nine books and more than 100 scholarly and popular articles. ROBERT W. SMITH is the co-author of National Geographic's Hubble: Imaging Space and Time. He is professor of history and director of the science, technology, and society program at the University of Alberta, Canada. His research interests are in the history of the physical sciences, astronomy, cosmology, and spaceflight in the United States. He is currently working on a project, the James Webb Space Telescope (a $5 billion project that is a joint enterprise of NASA, the European Space Agency, and the Canadian Space Agency, which will launch in 2014. ROBERT P. KIRSHNER, Clowes Professor of Science in the Harvard-Smithsonian Center for Astrophysics at Harvard University, accomplished groundbreaking work on supernovas and the expansion of the universe using the Hubble Space Telescope.