Implications of Sample Size for the Thermal Extraction of Volatiles from Lunar Regolith with the PROSPECT Instrument Package

The platform for resource observation and in situ prospecting for exploration, commercial exploitation, and transportation (PROSPECT) instrument package is under development by the European Space Agency for the upcoming Luna-27 mission to the lunar south pole. The purpose of the instrument is to detect and quantify volatiles on the lunar surface with the processing and analysis unit ProSPA. This paper describes the feasibility study and early breadboarding activities on ProSPA sample ovens during the Phase A study. The review of similar sample oven concepts led to the conclusion that none of these concepts satisfies new requirements of ProSPA regarding sample size and target temperatures. The trade studies presented in this paper include the estimation of power demands for scaled-up ovens, the influence of oven insulation, the compatibility of the utilized materials, and an experimental validation of the design. Experimental tests showed that the new oven design allows reaching the target temperatures and following most of the specified heating profiles with an imposed maximum power of 70 W. During the heating tests with the lunar regolith simulant NU-LHT-2M, sintering of the sample, reduction of the FeO content, and the creation of gas cavities were observed.