Information-Based Guidance and Control Architecture for Multi-Spacecraft On-Orbit Inspection

Abstract

We present an architecture for inspection or mapping of a target spacecraft, referred to as chief, in an orbit around Earth using multiple spacecraft, referred to as deputies (or) observers, in stable Passive Relative Orbits (PROs). We use an information gain approach to directly consider the trade-off between gathered data and fuel/energy cost. The four components of our architecture are: 1) information estimation, 2) state estimation, 3) motion planning for relative orbit initialization and reconfiguration, and 4) relative orbit control. The information estimation quantifies the information gain during inspection of a spacecraft, given past and potential future poses of all spacecraft. The estimated information gain is a crucial input to the motion planner, which computes PROs and reconfiguration strategies for each of the observers to maximize the information gain from distributed observations of the target spacecraft. The resulting motion trajectories jointly consider observational coverage of the target spacecraft and fuel/energy cost. For the PRO trajectories, we design a fuel optimal attitude trajectory that minimizes rest-to-rest energy for each observer to inspect the target spacecraft. We validate our architecture in a mission simulation to visually inspect the target spacecraft.