Constructing shuttle-mode architecture in cislunar space for reusable flight vehicles

In recent years, with the deepening of research in aerospace science and technology, the cislunar space has become a primary destination and base for exploration. Among the orbits within this region, lunar DRO (Distant Retrograde Orbit) and halo orbits are widely applied, and the dynamics and control of rendezvous which are critical aspects of both theoretical research and engineering applications. However, due to the complex dynamics in cislunar space and the diverse solutions under different mission demands, existing control methods still face technical bottlenecks in reusable situations. Traditional control modes are difficult to meet and balance requirements such as precision, stability, and energy consumption. Moreover, most are restricted to specific orbits or missions, lacking universality and flexibility. Therefore, we propose a shuttle-mode architecture for reusable flight vehicles in cislunar space, solving and evaluating orbit design problems under various practical conditions. The methods introduced in this paper will be applied to the construction of China's transit station for future lunar exploration. The reusable shuttle-mode architecture can be broadly divided into four functional components: lunar transfer from Earth to libration point orbits, far-range guidance, close-range approach, and station-keeping. Firstly, focusing on the transfer from Earth to Moon, and from LTO (Lunar Transfer Orbit) to DRO and halo orbits, two-impulsive thrust scenarios are investigated. Conditions are designed based on practical engineering requirements, and the performance is evaluated to determine the optimal parameters, such as departure points, arrival points, corresponding flight times, and energy consumption. The Lambert problem is solved, considering the Earth and the Moon as the central bodies to determine the preliminary orbit transfer solutions, respectively. These solutions are then refined considering the dynamics of the restricted three-body problem, and the optimal orbit parameters are obtained through iterations. Secondly, focusing on the far-range guidance in DRO and halo orbit, a two-impulsive guidance method is employed, calculating the timing and magnitude. In this step, approaches to under-determined problems in scenarios with reduced controllable dimensions are also discussed. Thirdly, for the close-range approach phase, linear approximation is used to achieve rendezvous and docking control. Finally, station-keeping and formation flying control strategies based on the target point method are investigated. By integrating these phases, the cislunar transfer, rendezvous, and docking missions in DRO and halo orbits for reusable flight vehicles could be accomplished.