Masatoshi Hirabayashi, assistant professor in aerospace engineering, is part of two on-going asteroid exploration missions — OSIRIS-REx, a NASA asteroid sample-return mission, and Hayabusa2, a Japanese asteroid sample-return mission. Hirabayashi investigates the geophysical features of these target asteroids.

OSIRIS-REx focuses on the collection of information about asteroid Bennu to gain a better understanding about the history of life and the solar system. The objectives of the study are to collect organic materials and conduct a detailed analysis of the samples from Bennu, a carbonaceous near-Earth asteroid. Other objectives also include mapping and investigating the mineralogical, geological and geophysical processes and the orbital evolution of this asteroid. Hirabayashi is a collaborator of the Radio Science team on OSIRIS-REx.