Cost analysis for single-stage (SSTO) reusable ballistic launch vehicles

Abstract

The ballistic SSTO Vehicle seems to be the prime candidate for a future reusable launch system for medium-size cargo due to its inherent technical and operational simplicity by limiting the number of stages to just one, and by using conventional rocket propulsion. Based on the MBB vehicle studies from 1969/70 and 1986 (BETA II) and taking into account requirements of the recent SDIO-Contract (“Delta Clipper”) a cost and cost driver analysis is presented using the TRANSCOST Model. First, the potential development cost for ballistic SSTO vehicles in the range of 200 to 1000 tons propellant mass are presented and the main influencal parameters - including the so-called “non-technical” factors - are discussed. The results are compared with actual total development cost of other launch systems. Then the potential ground and flight operations cost are discussed, based on the proposed “Standardized Launch Cost Definition (SLC, Level I, Level II Cost). In this case especially the impact of annual launch frequency on the cost per launch is shown, and the expected specific transportation cost compared with the present values of expendable launchers. A substantial cost reduction is to be expected, even under non-optimistic assumptions.