Application of PRA for Risk-Informed Decision-Making on a Space Station Payload

  • Todd Paulos
  • Alexis A. Flippen
Conference paper


This paper discusses the preliminary results of the first PRA study applied to a NASA payload designed to house various cell cultures and toxic fixatives aboard the International Space Station. The PRA serves two purposes. First, it is used as a tool to help target high-risk areas and thus improve the payload design and operations by avoiding potential over-design and under-design. Second, the results are being shown to NASA’s safety experts to ascertain whether equivalent or improved safety could be achieved in controlling the selected end state — crew exposure to fixatives — compared with traditional qualitative failure tolerance requirements. This first application of PRA to a payload demonstrates a practical design approach that could achieve one order of magnitude improvement relative to the baseline design, a noteworthy risk reduction. Future work is required to substantiate the findings and refine the analysis commensurate with higher fidelity design features.


International Space Station European Space Agency Leak Detection Access Operation Baseline Design 
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  1. 1.
    Safety Policy and Requirements for Payloads Using the Space Transportation System (NASA NSTS 1700.7B), January 1989.Google Scholar
  2. 2.
    Safety Policy and Requirements for Payloads Using the International Space Station, (NASA 1700.7B ISS Addendum), December 1995.Google Scholar
  3. 3.
    Flippen A, Navarro R, Larsen A and Stamatelatos M. The Application of Probabilistic Risk Assessment to Habitable Payloads: Utilization of Risk-Based and Traditional Rule-Based Methodologies, A First for NASA (IMECE2002-32445). Proceedings of IMECE’ 02, 2002 ASME International Mechanical Engineering Congress & Exposition, New Orleans, Louisiana, November 17–22, 2002.Google Scholar
  4. 4.
    Stamatelatos M, Dezfuli H, Apostolakis G, et al. Probabilistic Risk Assessment Procedures Guide for NASA Managers and Practitioners, Version 1.1, August 2002.Google Scholar
  5. 5.
    Flippen A and Paulos T. PRA Application and Status: Risk-Informed Decision-Making on a Space Station Payload. ESA-NASA Payload PRA Case Studies Technical Meeting. ESTEC, August 20–21, 2003.Google Scholar

Copyright information

© Springer-Verlag London 2004

Authors and Affiliations

  • Todd Paulos
    • 1
  • Alexis A. Flippen
    • 2
  1. 1.Todd Paulos, IncorporatedSimi ValleyUSA
  2. 2.Orbital Sciences Corporation, NASA Ames Research CenterMoffett FieldUSA

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