This paper proposes a framework to analyze the capacity of a launch vehicle systematically. Important mission requirements and flight parameters that influence the payload capacity of a given launch vehicle configuration are identified. The response surface models (RSM; the “analyzer”) for the launch capacity, coasting/burning arcs, and the velocity increment elements are developed. A series of trajectory optimization results, which are obtained with the “optimizer”, are used to determine the coefficients of the models. The case study to analyze the capacity of a low Earth orbit (LEO) launch vehicle configuration is conducted to demonstrate the validity of the proposed framework.