The 50th anniversary of NASA on 1 October 2008 found an agency in the midst of deep transition. In the closing year of the presidency of George W. Bush, only a month before the presidential election and in the midst of a worldwide economic crisis, the Agency was implementing a new Vision for Space Exploration intended to return humans to the Moon, to proceed onward to Mars, and to study the cosmos beyond. It was in this milieu that the History Division at NASA Headquarters com- missioned oral history interviews to be undertaken with NASA senior management. This volume is the result and provides a snapshot of the thinking of NASA senior leadership on the occasion of its 50th anniversary and in the midst of these sea changes. The reader of this volume may also wish to consult a companion volume in the NASA History series, NASA's First 50 Years: Historical Perspectives, the proceedings of NASA's 50th anniversary conference. (This publication is available here.) There the reader will find in-depth critical analysis from a variety of scholars of the diverse array of NASA's activities from 1958 to the present.