Dr. Harrison's primary focus is human adaptation to spaceflight and spaceflight-analogous environments, with particular emphasis on Antarctica as a prototype for Mars. He has written on habitability requirements for extended duration missions, and the integration of social and technical subsystems to meet advanced mission requirements. He was a member of NASA's Space Human Factors Engineering Science and Technology Working Group and is a member of the SETI (Search for Extraterrestrial Intelligence) Committee of the International Academy of Astronautics. He is involved in planetary defense (protecting the Earth from asteroids and comets) and chairs a subgroup of the Academy's Space Architecture Study Group. Besides his books, he's the author or coauthor of approximately 100 papers in a wide range of journals.