Spark plasma sintering and optical characterization of lunar regolith simulant

Roberta Licheri

Primo

;Roberto Orru;Elisa Sani

;Aldo Dell’Oro;Giacomo Cao

2022-01-01

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Abstract

To satisfy the essential needs, including energy requirements, for human and robotic space explorations on planetary objects like Moon, Mars and asteroids, the proper exploitation of resources available in-situ represents a crucial issue. Along this line, the present work investigates the potential of a sintered lunar regolith simulant (JSC-1A) for possible solar energy harvesting and thermal energy storage applications. Regolith simulant powders are first consolidated by Spark Plasma Sintering (SPS) at 700 and 900 °C to produce bulk samples with different relative densities, i.e. 86 and 98%, respectively, and surface porosities. Negligible changes from the compositional point of view are induced by SPS at 700 °C, whereas a decrease of the original glassy phase content is observed when operating at 900 °C. The optical properties of sintered samples and pristine regolith powders are compared, considering the spectral absorptance/emittance, the integrated solar absorptance and the integrated thermal emittance estimated in a temperature range representative for the ISRU application, i.e. from 100 to 1300 K. We found that sintering changes the optical properties of regolith in a process-dependent way, with an increased solar absorptance and thermal emittance shown by sintered pellets with respect to pristine powders.