Dr. Stephen G. Johnson is the director of the Space Nuclear Power and Isotope Technologies Division at the Idaho National Laboratory’s Materials and Fuels Complex.  Most recently this program fueled, tested and delivered the MMRTG for NASA’s Mars Scientific Laboratory mission. During his tenure, the laboratory has successfully pursued involvement in the Radioisotope Power Systems program. Following that involvement, the fueling and testing of space and terrestrial power systems operations were transferred from Mound Laboratory to the Idaho National Laboratory. He initiated the Technical Integration Office for the DOE’s national Space and Defense Power Systems program. This office focuses on cross-cutting initiatives, mission planning scenarios for nuclear power systems for DOE customers such as NASA, and provides resources for various other needs for DOE’s SDPS department. Johnson holds a bachelor’s degree with a double major in mathematics and chemistry from Lake Superior State University of Michigan and a Ph. D. in physical chemistry from Iowa State University.