Chapter 2 - Mission objectives, planning, and achievements of Hayabusa2

Abstract

The Japan Aerospace Exploration Agency developed and performed an asteroid sample return mission: Hayabusa2. Hayabusa2 is a Japanese, second-in-the-world asteroid sample return mission. Hayabusa2 visited the C-type asteroid Ryugu in 2018, stayed in the proximity of the asteroid for 1.5years, and returned to Earth in 2020. During the asteroid proximity operation, Hayabusa2 succeeded in delivering three mobile robots to the asteroid surface, performing two landing and sample collection activities, generating one artificial crater, and deploying three small objects into orbit around the asteroid. Although the terrain of Ryugu was found to be unexpectedly harsh for the Hayabusa2 spacecraft, the project successfully adjusted the operation strategy and improved the spacecraft's performance to finally complete the entire mission perfectly. Interplanetary operations, including launch, Earth swing-by, ion engine cruise, asteroid approach, and Earth reentry were also all successful. A total of 5.4g of Ryugu samples were confirmed to contain in the returned reentry capsule. This paper introduces the mission design of Hayabusa2 and describes the flight results while focusing primarily on engineering achievements.