A simulation of the joint estimation of the GM value and the ephemeris of the asteroid 2016 HO3

Abstract

Asteroid 2016 HO3 is the first of the two small bodies in the Solar System targeted by the Chinese Small Body Exploration Mission scheduled to be launched in the next few years. In this paper, we perform a full numerical simulation of a possible onboard radio science experiment to obtain the GM value of this tiny asteroid with a relative accuracy of ~10%. At such an accuracy, the GM value can be used to constrain the internal structure of the asteroid. We demonstrate that such an accuracy can be achieved through a joint estimation of the GM value and the ephemeris of the asteroid by using ground-based and onboard (spacecraft-asteroid) radiometric tracking data.