Shape-based, low-thrust trajectory design in alternating rotational coordinate system

This paper proposes a new strategy to design low-thrust trajectories using a shape-based method and an alternating rotational coordinate system. The shape-based method is a well-known strategy for designing spiral trajectories. In this method, a shape of the trajectory is first given and thrust profiles are then derived so that the equations of motion are satisfied. The alternating rotational coordinate system introduced in this paper is a rotational coordinate system in which the angular velocity varies depending on the position of the spacecraft. The advantage of this coordinate system is that spiral trajectories can be described with a simple shape. By combining these two tools, the given shape in the shape-based method becomes simple. In this paper, Sun-Earth L2 to Sun-Mars L1 transfer trajectories are designed as a demonstration of this strategy.