The Cassini spacecraft is designed to carry out an orbital tour of the Saturnian system and an investigation of the planet, its satellites, atmosphere, and its ring system. The space vehicle is powered by three Radioisotope Thermoelectric Generators (RTGs) which are mounted normal to the thrust axis of the vehicle. The nuclear heat source for each RTG consists of a stacked column of eighteen General Purpose Heat Source (GPHS) modules. Each module primarily consists of an aeroshell, two Graphite Impact Shells (GIS), and four Fueled Clads (FC). Each FC consists of a fuel pellet of plutonium-238 in the form of the oxide PuO2 encased in an iridium shell which serves to contain the fuel. An extensive program of experimental tests and analyses was conducted in support of previous missions (Galileo and Ulysses) which served to calibrate and validate the PISCES 2D-ELK continuum mechanics code. This paper describes the response of the GPHS-RTG system to a large number of potential launch accident environments empl...