PLANETARY PROBE MASS ESTIMATION TOOL DEVELOPMENT AND ITS APPLICATION TO TITAN AEROCAPTURE

An integrated mass properties estimation and aeroshell structural sizing design tool, called PROBECODES, is being developed for quick sizing of conceptual, atmospheric -entry planetary exploration vehicles. This tool will eventually integrate EDS PLM Solutio ns I -deasentry system geometry models, MicrosoftExcel -based entry system mass properties estimation spreadsheets, CFD generated aerothermodynamic loads, and structural sizing/optimizing software such as EDS PLM Solutions I-deas � or Collier Research's H yperSizer TM in order to create preliminary vehicle mass estimates, with particular emphasis on aeroshell structural sizing estimates. The MicrosoftExcel -based spreadsheet portion of the tool, called ProbeMAASS1 is currently being developed. It contains a mass properties/design database of previous planetary exploration vehicles and design studies; a mass properties breakdown and design description of these vehicles' major subsystems; mass estimation methods for the major subsystems of new vehicles using combinations of analytical techniques, empirical relationships, and user -specified data; and an automatic aeroshell structural finite element mesh generator. Currently this tool is limited to sphere -cone and ellipsled type vehicles, but future versions w ill include other types as they are developed. Though still under development, parts of this tool were successfully used to help quickly estimate Orbiter aerocapture system masses for a wide variety of TPS material/thickness and aeroshell size combination s for the Titan Aerocapture Systems Analysis study of 2002. In addition this tool was used to help estimate total launch wet mass for ten different Titan mission/launch vehicle configurations. This paper will present an overview of the full tool (PROBECO DES) and an overview of the mass properties estimation spreadsheets (ProbeMAASS1). Lastly, it will present the mass sensitivity results from the Titan Aerocapture study.