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Douglas Rickman

Publications and source records attributed to Douglas Rickman.

Recent Discoveries in Simulant Behavior and Regolith Handling

The past few years have seen an exciting increase in visibility for the use of in-situ resources to achieve sustainability at the Moon and Mars. This visibility and inclusion in the mission architectures has led to an explosion in the research and development of mining and processing of regolith at the Moon. However, there are still many fundamental issues regarding digging, transporting, and processing of lunar and Mars regolith that may slow the progress by multiple teams who need to understand these issues before proceeding with hardware development. The objective of this project is to utilize the same team of soil and thermal experts and unique facilities to allow for efficient and fast generation of fundamental data and dissemination of critical results to the larger community. The capability gaps being addressed include how to dig up hard, frozen resources, transport to the processing site, lifting/depositing into a hopper or reactor, and extracting the water, all without losing the primary product to the environment. Soil Seals: Much attention has been focused on the challenges with regolith inlet/outlet valves that must seal in process gases after being repeatedly ex-posed to abrasive regolith and dust particles. One possible solution that has been proposed is to design the inlet hopper or duct such that the bulk of regolith pro-vides sufficient sealing of the reactor. Tests are planned to parametrically measure the maximum del-ta-pressure that can be maintained across a column of soil before ‘blow-out’ occurs. Variables to be examined include column height and width, simulant type, and compaction.

Simulant↗

Design of New Lunar Highlands Simulants

The NU-LHT-series were created to develop reproducible methods of making simulants and to match the modal mineralogy, glass, and particle size distribution of Apollo 16 samples. Making the simulant at larger scales via an industrial plant is intended to reduce cost/ton.

Lunar simulants↗

Characterization of NU-LHT-4M Lunar Regolith Simulant Using Different Raman Configurations

As much as possible, structures to help sustain a long-term human presence on the moon will be constructed via in-situ resource utilization (ISRU) from lunar regolith. Various processes have been proposed to make lunar regolith-based construction materials, but one complication is that the lunar regolith is relatively complex in terms of composition and can vary quite significantly from one site to another. Some of these methods to make lunar regolith-based construction materials are quite sensitive to the composition and so in-situ methods for evaluating the composition of the lunar regolith could be critical. Various analytical instrumentation has been proposed for in-situ characterization of the composition of regolith on planetary bodies. Raman spectroscopy has been suggested and has some advantages over other in-situ techniques, such as potential for relatively high spatial resolution, direct determination of the mineralogy (while other methods may only infer the mineralogy), nondestructive analysis, relatively simple instrument configurations, and minimal sample preparation/handling. For example, Raman instrumentation has already been deployed in rover-based missions to Mars. Previously, we developed the Standoff Ultracompact Micro-Raman Sensor (SUCR), which is a portable Raman spectroscopy instrument capable to be integrated into a rover or onto a lander. Here, we present work on Raman spectroscopy measurements of NU-LHT-4M lunar simulant using three different Raman instruments with different configurations for collecting Raman data with the goal to explore the effect of these different configurations on the results, especially for use in a lunar environment.

Raman Spectroscopy↗

Evaluation of South Dakota Aggregate as Martian Simulants

This research investigates aggregate sources in South Dakota to simulate martian aggregate for use in future martian concrete infrastructure. This effort supports the Moon to Mars Planetary Autonomous Construction Technology (MMPACT) project lead by the National Aeronautics and Space Administration (NASA). Currently, martian simulants are not produced in large quantities or from many geologic sources. Previous work has primarily focused on tholeiitic basalt even though the martian surface has diverse geology especially in crater locations. Various landing sites were selected to explore martian regolith compositions and textural characteristics. From these results, it was determined that locations with basaltic andesite would best match geological sources in South Dakota. These local regolith sources were then collected and characterized. A comparison between the local and martian aggregate is provided. Ultimately, this work will contribute to binder production for Additive Construction using In-Situ Resource Utilization (ISRU) processing for surface construction.

Aggregate↗