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A study is performed to ascertain the validity of the use of inviscid and viscous simulation methods to predict the axial and normal forces during a launch abort scenario for manned space flight vehicles. The proximity drag character of the Apollo launch escape vehicle (LEV) was studied in detail in a wind tunnel during the Apollo program. Simulation results obtained during the present effort are compared to the Apollo era wind tunnel experiments. The validated simulation techniques are applied to assess the possibility of recontact between the crew capsule and the service module after a launch abort is initiated. The natural extension of the method is to assess the risk associated with the new Crew Launch Vehicle’s escape system.

A probabilistic risk assessment (PRA) approach has been developed and applied to the risk analysis of capsule abort during ascent. The PRA is used to assist in the identification of modeling and simulation applications that can significantly impact the understanding of crew risk during this potentially dangerous maneuver. The PRA approach is also being used to identify the appropriate level of fidelity for the modeling of those critical failure modes. The Apollo launch escape system (LES) was chosen as a test problem for application of this approach. Failure modes that have been modeled and/or simulated to date include explosive overpressure-based failure, explosive fragment-based failure, land landing failures (range limits exceeded either near launch or Mode III trajectories ending on the African continent), capsule-booster re-contact during separation, and failure due to plume-induced instability. These failure modes have been investigated using analysis tools in a variety of technical disciplines at various levels of fidelity. The current paper focuses on the roles and impacts of the higher-fidelity methods on this process and, by association, the roles and impacts of the high performance computing resources of the Columbia supercomputer system at NASA Ames Research Center.