The Cassini Mission probabilistic risk analysis: Comparison of two probabilistic dynamic methodologies

This paper describes a comparison between two dynamic methodologies used in the probabilistic risk analysis (PRA) of the Cassini Mission. The main Cassini PRA was performed by Lockheed Martin. A combination of Monte Carlo algorithms and event-tree logic was used to perform the study. Results were validated using an alternative method, the Discrete Dynamic Event Tree (DDET) methodology. jor conclusions of the paper are 1) performing a dynamic PRA of large scale ‘real-life’ systems is feasible and 2) given the same ground rules and assumptions, two dynamic methodologies would give the same results.