Optimal staging of reusable launch vehicles considering velocity losses

Abstract

This paper proposes an optimal staging method for reusable launch vehicles considering velocity losses. The proposed method expands a traditional stage optimization approach for expendable launch vehicles by introducing the descent phase of the separated stage and combining it with the trajectory optimization procedure. For a reusable stage, the structural ratios responsible for its ascent and landing phases are defined to formulate the optimal sizing problem and optimized along with variables for traditional staging problems. An optimal staging case study on a reusable launch vehicle demonstrates the effectiveness of the proposed method.