Development of assessment methods of lunar soil simulants with respect to chemical composition

Abstract

The present study concerns a development of assessment tools for lunar soil simulant chemical composition. Prior to developing the methodology, lunar soil was investigated by using the lunar soil samples from Apollo missions then quantifying the average value and standard deviation of the respective oxides. For the assessment methods, the error index and grade index methods were simultaneously developed. As for the error index method, the difference between lunar soil and lunar simulant was summed up, considering the concentration of respective oxides in lunar soil. Thus, a lower value for this index would indicate higher similarity to the lunar soil. To reflect the variation in oxides in lunar soil (i.e., standard deviation), a grade was given to each oxide in the lunar simulant in the grade index method. In the present study, 6 different grades were used to rank the grade score to each grade. The summed value of the grade score is indicative of the similarity of lunar simulant to lunar soil. To demonstrate the feasibility of these methods, the JSC-1 and NU-LHT-1M lunar simulants were taken as examples. It is expected that these assessment method would be useful to rank and evaluate the quality of lunar simulants.