Safety Analysis Modeling of the Mars Science Laboratory Mission Launch
Fall 2010 Smart Materials and Systems Seminar Series
Timothy Bartel, PhD
Sandia National Laboratories
The National Aeronautics and Space Administration’s (NASA’s) Mars Science Laboratory (MSL) Project will send a rover the size of a small dune buggy to the surface of Mars with a launch window in the fall of 2011. The MSL mission is designed to conduct a Mars habitability investigation, with habitability defined as the “capacity of the environment to sustain life” (i.e., the potential of a given environment to support life at some time, past or present). The MSL rover design uses a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) to provide continuous power on the Martian surface; the power requirements of the MSL rover cannot be met with photovoltaic cells. The MMRTG contains 4.8 kg of plutonium dioxide (PuO2) in ceramic form (primarily plutonium-238) and will provide 120 W electrical power at the beginning of mission (approximately 2000 W thermal). Due to the radioactive nature of this material and the potential for accidents involving its release to the environment, safety is an inherent consideration in all steps from mission design through launch.
This talk will describe the interdisciplinary requirements for modeling a launch accident with a focus on the thermal response of the PuO2 fuel pellets in the thermal environment from the launch vehicle propellants. Similar to the US Space Shuttle launch vehicle, the configuration of modern expendable launch vehicles is a combination of both liquid and solid rocket motors. The thermal analysis must consider the different characteristic burn times for both of the propellants. Both experimental and modeling efforts of the thermal analysis will be presented.
Dr. Bartel received his PhD in engineering physics at the University of Wisconsin-Madison in 1987. He was a consultant at Los Alamos National Laboratory for 2 years and is currently a principal member of the technical staff at Sandia National Laboratories. His interests include nuclear reactor safety analyses, numerical simulation of rarefied gas dynamics, thermo-chemistry modelling and numerical modeling the transient response of advanced nuclear fuel pins.