Takuto Ishimatsu is a Ph.D. candidate in Aeronautics and Astronautics at MIT. He holds B.Eng. and M.Eng. degrees from the University of Tokyo in Japan and a S.M. degree from MIT, all in Aeronautics and Astronautics. His research interests include space systems and logistics, system safety, astrodynamics, and aerodynamics. Tak is working on his Ph.D. research on graph-theoretic modeling framework for space logistics in the MIT Strategic Engineering Research Group (SERG), led by Prof. Olivier de Weck. In his dissertation, Tak is developing a new multi-commodity network flow modeling method using requirement, transformation, and constraint matrices and applies it to human exploration of Mars. In addition to the space application, Tak is also applying this modeling method to multi-layer infrastructure planning in Saudi Arabia for the CCES SIPS project, which adds an optimization function for operation and investment in the SIPS decision support tool.