-- Ames Research Center
Division Staff Scientist, Space Exploration Projects Office
--NASA HQ
Chief, Space Instrumentation and Studies Branch
Chief, Systems Engineering and Analysis Office, Centrifuge Facility Project Office (Space Station life science facility)
Deputy Chief, Space Projects Division
Chief (acting), Space Projects Division
Ames Mars Pathfinder Project Manager
Associate Director, Space Directorate
Deputy Director, Space Directorate
Founding Director, NASA Astrobiology Institute
Manager, Lunar Prospector Mission
Associate Director, Astrobiology and Space Programs
First Mars Program Director
-- Ames Research Center
Deputy Director for Research
Director, NASA Ames Research Center
