Hubble Space Telescope Operations Manager, NASA Goddard Space Flight Center, 1983-1987
Chief, Mission Operations Division, Mission Operations and Data Systems Directorate, NASA Goddard Space Flight Center, 1987-1989
Deputy Director, Mission Operations and Data Systems Directorate, NASA Goddard Space Flight Center, 1989-1990
Associate Director for Hubble Space Telescope Flight Projects, NASA Goddard Space Flight Center, 1990-1994
Deputy Center Director, NASA Goddard Space Flight Center, 1995
Center Director, NASA Goddard Space Flight Center, 1995-1998
Associate Administrator, Office of Space Flight, NASA Headquarters, 1998-2001
