The aim of the present study is to investigate alternative reusable launch vehicle concepts and to provide a comparison of two different vehicle cone gurations. The e rst concept vehicle uses airbreathing engines to perform a powered booster e yback mission, whereas the second concept employs only aerodynamic lift to achieve booster e yback. The optimization software employs a system parameter optimization, in conjunction with a trajectory parameter optimization, to calculate the optimal mass split and corresponding optimal trajectory. A reference mission is used to comparelaunch vehicle payloads fora e xed grossliftoffweight, assuming launch from Woomera Prohibited Area, South Australia. The payload for a vehicle using a powered e yback strategy is found to be considerably higher than that obtained by a vehicle employing an aerodynamic glide return e ight.