Thermophysical Model Development for Hera Mission to Simulate Non-Gravitational Acceleration on Binary Asteroid

Abstract: The surface temperature of an asteroid is fundamental information for the design of an exploration mission and the interpretation of scientific observations. In addition, the thermal radiation of the asteroid causes a non-gravitational acceleration that induces secular changes in its orbit and spin. We have been developing a numerical calculation library for simulating the dynamics and thermophysics of asteroids. The asteroid dynamical simulator, \texttt{Astroshaper}, can calculate the temperature distribution based on a 3-dimensional shape model of an asteroid and predict the non-gravitational acceleration. In recent years, asteroid exploration missions such as Hayabusa2 and Hera have been equipped with thermal infrared imagers. The asteroid thermography can provide the thermal properties of the surface material of the target bodies. The functionality of thermophysical modeling in \texttt{Astroshaper} contributes to simulating the thermal environment on the asteroids, estimating the thermal properties, and predicting the dynamical evolution controlled by the non-gravitational effects.