Abstract
In this paper, integrated optimization of SSTOs with two different engines systems was performed. As a result, although engine performances were different, similar airframe configurations and flight paths were obtained. In addition, different flight path with the similar airframe configuration was obtained as the temporary optimum solution in the optimization process. This transition of the optimum solution indicates the influence of SSTO's engine performance on its airframe configuration and flight path through the integrated optimization. Simultaneously, it was shown that improvement of the specific impulse in a low Mach number may improve the feasibility of a SSTO.
