This thesis proposes a new methodology to provide compromises between different spacecraft design and space mission architectures, particularly for complex missions. Therefore, the effectiveness of the novel approach is assessed through a case study regarding the delivery of a payload on the lunar surface. As space missions become more complex and long-term, there is a more significant need for an effective method of designing and optimizing these complex missions. While most traditional mission design studies focus on spacecraft trajectories, recent research on space logistics has introduced rigorous mathematical optimization in the design of multi-mission space campaigns to try to automate the mission design.