Preliminary Mission Analysis and Design of a Cubesat Mission to the Didymos Binary Asteroid System

Nanosatellite missions represent a promising option for the exploration of the near-Earth asteroid population since they provide low-cost versatile platforms for scientific observations. This paper describes the orbital analysis for the DustCube mission, which was preliminarily selected to reach the binary asteroid system Didymos on-board ESA’s AIM spacecraft. Possible candidate orbits that exploit the binary nature of the system and satisfying the mission requirements and constraints were identified. The overall feasibility of the proposed Concept of Operations was then addressed by integrating the spacecraft trajectories in a realistic dynamical environment, evaluating their sensitivity to state errors, and estimating the accuracy requirements of the Orbit Determination and Control Subsystem (ODCS). The proposed operational concept proved consistent with the maneuvering capabilities of a CubeSat platform in terms of frequency of the station-keeping maneuvers and total delta-v budget. The proposed solution combines an initial parking orbit at the L4 equilibrium point with a Distant Retrograde Orbit for proximity operations, allowing to fulfil all mission requirements. However, this result is strictly coupled with the overall performance of the orbit determination system, which is required to allow for safe operations.