Documents Archive
Mr. Michael J. Kelly
Mr. A.C. Charania
Dr. John R. Olds
Mr. Dominic DePasquale
SpaceWorks Engineering, Inc. (SEI)
Abstract:
Future reusable launch vehicles are considered to have potential benefits compared to existing and/or expendable systems. These benefits are likely to arise from reductions in turnaround time and recurring operations costs in labor and materials. Quantifying these operability and affordability effects, in some manner beyond using historical analogies, has proven difficult for the systems analysis community. Additionally, to quantify whether these potential recurring advantages translate to overall programmatic benefits requires analysis of design, development, test and evaluation times and costs, along with total first unit and related acquisition cost metrics.
SpaceWorks Engineering Inc. (SEI) has developed, through research and quantitative modeling, a discrete event simulation to predict turnaround time, recurring ground operations cost, and other operations metrics for future launch vehicles. Conceptual design teams, including ones working out of NASA Langley Research Center and the Air Force Research Lab, have utilized this model for several reusable launch vehicle designs. Rocket-based combined cycle, turbine-based combined cycle, and pure rocket designs are among those analyzed. Additional modeling efforts are focused on development and acquisition metrics for these and similar vehicle concepts. This modeling goes beyond traditional historical modeling efforts by focusing on subsystem-level processes and how the resources required for these processes are utilized.
The models are implemented in the discrete-event simulation software Arena, commercially available from Rockwell Automation. Inputs for the operations model include descriptions of the basic vehicle concept of operations, mission models, and performance information. Outputs presented include estimated times for overall vehicle turnaround as well as various stages of that process, along with recurring operations costs including labor, fuel, and spare parts. The development and acquisition model design in process receives similar inputs to allow holistic time-based and cost-based analysis incorporating all stages of a launch vehicle program. In the early part of the twenty-first century, both the theoretical underpinnings and actual simulation software capabilities are present to create a usable, activity-based systems analysis capability for metrics related to reusable launch vehicle operability and development, acquisition, and recurring operations affordability.
Bibliographic Reference:
Kelly, M., Charania, A., Olds, J., DePasquale, D., "Discrete Event Simulation of Reusable Launch Vehicle Development, Acquisition, and Ground Operations," AIAA-2009-6484, Space 2009 Conference & Exposition, Pasadena, CA, September 14-17, 2009.
