Optimal staging of reusable launch vehicles for minimum life cycle cost

Abstract

This paper proposes an optimal staging procedure of a reusable launch vehicle considering its life cycle operations.Instead of minimizing the lift-off mass of a single launch adopted by traditional optimal sizing problems, the proposed procedure minimizes the total life cycle cost of reusable stages using an integrated optimization module and a cost model. The recurring/nonrecurring cost models are established to compute the life cycle cost of a reusable launch vehicle throughout the operational period of its reusable stage. The integrated optimization module obtains a vehicle configuration and ascent/descent trajectories to put the desired payload into the target orbit while minimizing the expendable stage mass for a given reusable stage. The validity and effectiveness of the proposed procedure are demonstrated through an optimal staging case study for a real reusable launch vehicle, Falcon 9.