Marburger's tenure as Director was the longest in the history of that post. After the September 11 attacks, he helped to establish the DHS Directorate for Science and Technology within the new Department of Homeland Security. He has been called a central player opposing new restrictions of international scientific exchanges of people and ideas after the attacks. He later was responsible for reorienting the nation's space policy after the Space Shuttle Columbia disaster, and played an important part in the nation's re-entry into the International Thermonuclear Experimental Reactor program. Marburger was also known for his support of the emerging field of science of science policy, which seeks to analyze how science policy decisions affects a nation's ability to produce and benefit from innovation.