Life-cycle-cost considerations for launch vehicle liquid propellant rocket engine

Abstract

This paper discusses the engine cost contribution to the life cycle cost of launch vehicles and what cost differences exist between engines designed for expendable and reusable vehicles. The cost drivers in the engine development and production phases, and during vehicle flight operation, are delineated. Analysis of historical cost data and parametric cost modeling were used as a basis for the cost observations. Several measures for potential engine cost reduction are discussed. These include the early use of a test bed, and the selection of the Space Shuttle Main Engine reliability and test approach for development; the introduction of multiyear buys for expendable engines to capitalize on the cost advantages of high production quantities and rates through low-cost fabrication method with automation; and the decrease in operation and support costs for reusable engines due to the use of long life and high mean time between replacement components, and by extensively employing condition monitoring and diagnostic instrumentation. The lessons learned from past booster engine programs, e.g., the F-l, J-2, and SSME, with regard to engine life cycle cost, provide some valuable insights for the next generation of launch vehicle booster engines.