A Critical Parameter Optimization of Launch Vehicle Costs

Abstract

A parametric analysis aimed at minimizing costs of payload to low earth orbit is undertaken. By identifying a range of payload sizes, the effects of manipulating a number of critical parameters involving vehicle configurations on payload costs were examined. Vehicle configurations encompass single stage and multistage vehicles with combinations of airbreathing and/or rocket propulsion systems. Launch systems could be expendable or reusable on a stage-by-stage basis. Staging velocity is optimized for minimum cost at each design point. The costing model includes the effects of learning on production and operations, discount factors for multiyear investments, and the use of "refurbishment fraction" (fraction of initial procurement costs required for reusable vehicle refurbishment between flights) for estimating maintenance and turn-around costs. Overall vehicle recurring and nonrecurring costs are estimated based on sets of inert-mass cost estimating relations drawn from published sources.