Davide Guzzetti

Attitude Responses in Coupled Orbit-Attitude Dynamical Model in Earth–Moon Lyapunov Orbits

The attitude motion of a rigid spacecraft in fully nonlinear reference orbits is explored in this investigation, within the context of the planar circular restricted three-body problem. The reference trajectories originate from the Lyapunov families about the Lagrangian points L1 and L2 in the Earth–Moon system. Kane’s method is employed to derive the equations of motion, which are numerically solved. The capability to reproduce the dynamic response is leveraged to understand the attitude behavior across the Lyapunov families. The problem formulation and the simulation environment are detailed. The inertia properties of the spacecraft are varied across the periodic family of orbits. Finally, attitude maps are introduced to summarize the results and identify the regions, in terms of the orbit size and inertia properties, where the spacecraft maintains the initial orientation with respect to the rotating frame in the circular restricted three-body problem.

Coupled Orbit-Attitude Dynamics in the Three-Body Problem: A Family of Orbit-Attitude Periodic Solutions

Many relatively new techniques are being developed to incorporate the Circular Restricted Three-Body Problem model into the early stages of the trajectory design. However, the attitude mission profile mostly remains reliant on methods established for Keplerian dynamics. A coupled orbit-attitude model might leverage the Circular Restricted ThreeBody Problem dynamics to explore alternative, possibly more effective, profiles also in terms of the attitude response. The goal of this analysis is a nontrivial solution that is periodic both in its orbital and attitude states, when observed from the rotating frame. In the current investigation, tools largely employed for the orbital analysis (e.g., Floquet theory, differential corrections and continuation schemes) are effectively applied also in the coupled orbit-attitude problem. Organized and predictable motion appears to naturally exist under certain conditions in such a model. As an example, a new family of orbit-attitude periodic solutions is detailed.