Masatoshi "Toshi" Hirabayashi

Associate Professor
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Dr. Masatoshi (Toshi) Hirabayashi bridges planetary science mission technologies and planetary science to harmonize them on planetary science exploration missions. His expertise is in space operations, particularly exploring techniques to achieve both engineering and science requirements under mission constraints. His engineering targets are orbiter/lander design and navigation techniques enabling scientific infestations, while his scientific focuses are on the origin and evolution of small bodies, moons, and terrestrial bodies to explore planetary volatiles. His academic efforts propel planetary science exploration missions.

He was involved in a series of planetary missions, including JAXA/IKAROS (solar sail mission), JAXA/Hayabusa 1 and 2 (small body sample return mission), NASA/OSIRIS-REx (small body sample return mission), and ESA/JAXA/Bepi-Colombo (Mercury orbiter mission). Recently, he was a Co-I of NASA/DART (planetary defense mission). He currently serves as a Co-I of NASA/VIPER (lunar rover mission). He also leads Hayabusa 2# as a Science Integration Lead. 11471 Toshihirabayashi is named after him for his contribution to small-body research.


Space operations, celestial mechanics, planetary science, and design & navigation.

  • Ph.D., Aerospace Engineering, University of Colorado Boulder, 2014
  • M.S., Aerospace Engineering Sciences, University of Colorado Boulder, 2012
  • M.S., Aeronautics and Astronautics, University of Tokyo, 2010
  • B.S., Mechanical and Aerospace Engineering, Nagoya University, 2007
Distinctions & Awards
  • 2023, Finalist of PROSE Award for Excellence in Physical Sciences and Mathematics of the Association of American Publishers, in the Chemistry, Physics, Astronomy, and Cosmology area
  • 2022, NASA Group Achievement Award through the Lunar Dust Science Definition Team
  • 2022, Auburn University College of Engineering Journal Faculty Research Award
  • 2021, Hayabusa2 Honor Award, Hayabusa2 team
  • 2019 – present, Adjunct professor appointment in the Geoscience department
  • 2017, Asteroid 1981 EH48 was named after myself, 11471 Toshihirabayashi