Open Loop Safe Trajectory Design for Cislunar NRHO Rendezvous

Autonomous rendezvous and docking/berthing in presence of two main attracting bodies is considered one of the key operations for future space explorations. Dynamic modeling, and relative guidance and control algorithms must be designed so as not to compromise the safety of the mission and to provide a collision-free environment. Two of the main approaches to guarantee collision avoidance are a closed loop active control design, and an open loop passive strategy. The paper presents the development of a passive safety procedure based on manifold theory, which provides collision-free trajectory in the presence of specific actuator failures. The proposed procedure is applied to the scenario defined by the European Space Agency Heracles study, for rendezvous in cislunar orbits.