The development of reusable launch vehicles in space exploration is a significant paradigm shift in the aerospace industry. Among numerous approaches to fully reusable launchers, a flyback booster, complemented by the emerging importance of spaceplanes, stands out as a viable solution. To outweigh the drawbacks associated with the cost, a reliable mission design has to be performed for the developed flyback booster. The aim of this thesis is to increase the overall understanding of the mission characteristics to decrease the risks associated with fly back trajectories, while optimizing the mission design process. Part of the study concluded that the mission design process can be further optimized by utilizing a detailed design space exploration. It is identified that to achieve such results, it is important to utilize various design space methods as each method reveals a different level of interaction between the factors. Upon understanding the design space better, a trajectory optimization is performed for both powered and unpowered flyback boosters. The findings suggest that while the unpowered capabilities are not sufficient to obtain the desired final distance-to-go, powered vehicle can achieve the mission objectives successfully.