Simultaneous Optimization of Launch Vehicle Stage and Trajectory Considering Flight-Requirement Constraints

A conceptual design of a launch vehicle encompasses various disciplines, such as structural design, aerodynamics, propulsion systems, flight control, and stage sizing. This paper focuses on optimizing trajectory and stage size. Traditional approaches used for the conceptual design of a launch vehicle conduct the stage and trajectory designs sequentially, often leading to high computational complexity and suboptimal results. This paper presents an optimization framework that addresses both trajectory optimization and staging in an integrated way. The proposed framework aims to minimize the lift-off mass while satisfying the constraints on flight requirements (e.g., maximum dynamic pressure and the impact points of separated parts). A case study demonstrates the advantage of the proposed framework compared to the traditional sequential optimization approach.