Integer Linear Programming-Based Design Method for Walker Constellation Deployment

<p indent="0mm">The enumeration method is traditionally used for Walker constellation deployment design; however, this approach is low efficient and generates a heavy workload. Considering these disadvantages, this study proposes an integer linear programming-based deployment design method. Based on the characteristics of the Walker constellation, the deployment design process is decoupled into two steps: (1) deployment design and optimization of the unit orbit, and (2) deployment design and optimization of the Walker constellation. In the first step, the optimization object is the minimal launch cost. The optimization constraints are that the launch vehicles must provide sufficient transport capacity for the unit orbit and appropriate positions for the satellites of the unit orbit. In the second step, the optimized unit-orbit deployment is inherited, and the optimization object is, again, the minimal launch cost. However, the optimization constraints pertain to the deployment year-plan, launch-vehicle productivity, launch period, and launch-site launch capacity. Integer linear programming is used to implement the two steps of the design process, which yields the optimized deployment of the Walker constellation. The results demonstrate that the constellation deployment design is highly efficient while the subjective decision-making process is simplified.