Characteristics and close-range exploration methods of near-Earth asteroid 2016HO₃

The characteristics of asteroids are vital parameters for planning asteroid exploration missions. These characteristics have been explored in close range for some typical asteroids, and are summarized in the article. This allows estimates of the characteristics of asteroid 2016HO₃, the target of the first Chinese asteroid exploration mission, Tianwen 2. We obtain 80 characteristic parameters in 9 categories and analyze their impacts on the mission. By comparing three close-range exploration modes, we provide advantages and disadvantages of each, and propose suitable methods for the exploration of 2016HO₃. Owing to the weak gravity and small size of 2016HO₃, a combination of multiple hovering positions and active orbiting is recommended for scientific exploration.