Date of Award
2024
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Aerospace Systems Engineering
Committee Chair
Jason Cassibry
Committee Member
William Emrich
Committee Member
Robert Frederick
Committee Member
George Nelson
Research Advisor
L. Dale Thomas
Subject(s)
Roving vehicles (Astronautics)--Design and construction, Propulsion systems, Nuclear fission, Mars (Planet)--Exploration
Abstract
A comprehensive analysis was performed on the impact of embedding a Kilopower-style fission reactor into a pressurized rover on architectural performance for a sample lunar, Mars opposition, and Mars conjunction mission. The high gamma ray flux necessitated the addition of substantial shielding for the crew. A single material shielding analysis using the Taylor formulation revealed that varying the distance between the crew and the reactor core from 3 m to 6 m reduced the required shielding thickness by 7%. Increasing the power output of the reactor from 3.4 kWe (comparable to radioisotope power capability) up to 10 kWe (Kilopower design limit) resulted in a 6% increase in shielding thickness. Implementing directional shielding principles based on crew position relative to the core reduced shielding mass by 19% and shutting the reactor down before exiting the pressurized rover allowed for an additional 65% shielding mass reduction. Reducing the size of the reactor core required a correspondingly larger battery, where a comparison between a 6.5 kWe reactor and a 10 kWe reactor resulted in a total mass difference of less than 2 kg despite a larger radiator that was required for the 10 kWe case. A literature review was conducted to study all adjacent systems to the fission rover concept and were found to be lacking in one or more areas addressed by the fission rover architecture. Key Performance Parameters were calculated and used to trade the fission rover architecture with NASA’s baseline architecture derived from the best available literature. The fission rover architecture outperformed the lunar and opposition Mars missions in three of the five parameters, while matching the performance of NASA’s baseline in the other two. For conjunction Mars mission, the fission rover architecture was found to outperform NASA’s baseline in three of the five parameters, matching NASA’s baseline for one parameter, but with a cost increase of about 15%.
Recommended Citation
Bendoyro, Alexander Constantine, "Nuclear fission rovers for Martian exploration" (2024). Dissertations. 436.
https://louis.uah.edu/uah-dissertations/436