Date of Submission
5-2025
Document Type
Thesis
Degree Name
Master of Science in Mechanical Engineering
Department
Mechanical and Industrial Engineering
Advisor
Sumith Yesudasan, Ph.D.
Committee Member
Genesh Balasubramanian, Ph.D.
Committee Member
Suk Bum Kwon, Ph.D.
Keywords
Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), Radioactive Materials, Structural Integrity and Resilience, Multiphysics Simulation Software, Impact Scenarios, Finite Element Analysis
LCSH
Radionuclide generators, Radioactive substances, Metals--Impact testing, Computer simulation, Finite element method
Abstract
A Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) is a radioisotope power system designed for use within both planetary atmospheres and the vacuum of space. A radioisotope power system uses a radioisotope fuel source which generates heat that is then converted into electricity by the system’s thermocouples. These generators are used as a power source on space missions with very long service durations. MMRTGs have a required usage lifespan of roughly fourteen years, therefore the system must withstand stressors without suffering significant structural damage that would affect their functionality.
It is important to take into consideration that MMRTGs house radioactive materials; therefore, their resilience is crucial not only to the success of the space mission but also to the safety of the public. In order to minimize the dangers posed by these nuclear materials it is necessary to optimize the structural integrity of the MMRTG. Thus, ensuring that in the event of a mission failure wherein the MMRTG is sent into Earth’s atmosphere, the nuclear material housed within the generator remains contained. For these reasons, it is necessary to ensure the structural integrity and resilience of the MMRTG and to provide recommendations for material optimizations that can be applied to its construction. In service of this goal, this paper presents a finite element analysis (FEA) of an MMRTG model subjected to various impact scenarios. An analysis of the MMRTG’s structural integrity under gravitational loads will be performed along with a direct drop impact test and a vibrational analysis with the purpose of simulating those shocks that the MMRTG would experience while traversing Martian terrain via Mars rover. Using COMSOL Multiphysics, a comprehensive 3D model was developed, incorporating boundary conditions and material properties appropriate for simulating impact environments. Data on PSD estimation for terrain simulation, construction dimensions, and material properties was gathered via publicly available documents from various sources including the United States Department of Defense (DoD) and The National Aeronautics and Space Administration (NASA). By utilizing this information this study aims to understand the structural integrity and resilience of MMRTGs under relevant conditions, with a focus on time-dependent shock load application and structural response.
Recommended Citation
Brown, Christopher, "Structural Vibration Analysis of The Multi Mission Radioisotope Thermoelectric Generator (MMRTG) on the Martian Surface" (2025). Master's Theses. 256.
https://digitalcommons.newhaven.edu/masterstheses/256