Master of Science
Planetary Science and Exploration
Osinski, Gordon R.
There are still many gaps in improving the fidelity of lunar regolith simulants to simulate more properties. This study compares some fundamental physical and mineralogical properties of three types of lunar highland regolith simulants: LHS-1, a commercial product with high mineralogical fidelity; UWO-1G, an original simulant that is the main component of LHS-1; and UWO-1S, another original product that is attempted to produce shocked grains in lunar simulants from pulverizing and mixing impact rocks sourced from the Mistastin Crater.
Preliminary results indicated that even though all simulants are composed of mostly plagioclase minerals and have similar particle size distribution patterns, the UWO-1S grains exhibit less angularity compared to LHS-1 and UWO-1G, as well as poor ability to regain void ratio during consolidation tests. Both are indications that the grain strength is possibly weaker due to impact events, however further characterizations are also recommended for more evidence.
Summary for Lay Audience
The interest in returning to the Moon, and potentially building habitats and other infrastructures, has been rising globally. Past lunar exploration, such as USA’s Apollo crewed landing missions and autonomous sample return missions from the former USSR’s Luna Program, and China’s Chang’e Program, have determined that lunar regolith could be a critical hazard but also a valuable resource. In order to design future equipment for safe and sustainable lunar exploration, dozens of simulated lunar regolith, or “simulants”, have been produced worldwide for testing materials that will come into contact with lunar regolith.
However, lunar regolith is a complex product resulting from being exposed to the harsh space environment. Repetitive impact events and space radiation resulted in many unique features within lunar regolith that are difficult or even impossible to simulate. Therefore, current simulants mostly only replicate one or a few properties of lunar regolith for specific research purposes.
In this research, three types of lunar highland simulants were selected to compare some of their fundamental properties, which focuses on the discussion of the role of mineralogical accuracy and shocked grains within lunar simulants. We chose LHS-1, which is a commercial product that aims at high mineralogical fidelity, created UWO-1G, which only used one type of feedstock that is the main component of LHS-1, and created UWO-1S, which attempted to produce shocked grains from pulverizing impact rocks.
Preliminary comparison results confirmed that these simulants contain very similar mineralogical components, and their particle size distributions are closely matched to allow a fair comparison of physical properties. LHS-1 and UWO-1G did not differ from each other too much, but UWO-1S demonstrated weaker physical strengths, which could imply that the grain durability is weaker than the other two. Further characterizations and additional comparative samples are suggested to strengthen the evidence.
Zhang, Xiao Chen, "Lunar Regolith Simulant Behaviours Affected by Shock Metamorphism and Mineralogy" (2021). Electronic Thesis and Dissertation Repository. 8329.