He is an expert in near-Earth asteroid formation and evolution. He is the leader of NASA's OSIRIS-REx Asteroid Sample Return mission. OSIRIS-REx is the United States' premier mission to visit one of the most Potentially Hazardous near-Earth Asteroids, survey it to assess its impact hazard and resource potential, understand its physical and chemical properties, and return a sample of this body to Earth for detailed scientific analysis. The spacecraft launched in September 2016 and began its journey to Bennu, a carbon-rich, near-Earth asteroid. The spacecraft rendezvoused with Bennu in 2018 and successfully obtained a sample in October 2020. The spacecraft embarked on its return voyage to Earth on May 10, 2021. Sample return to Earth occurs in 2023. He also maintains an active research program in Cosmochemistry and Meteoritics.