Accurate measurement of the thermophysical properties of lunar regolith is essential for the success of lunar missions. However, reliable data on the specific heat of lunar regolith simulants, such as FJS-1 and JSC-1A, are currently unavailable. Wakabayashi et al. measured the specific heat (Cp) of FJS-1. The specific heat of JSC-1A can be calculated from the volumetric heat capacity (ρCp) reported by Pinheiro et al. and the density (ρ) reported by Meurisse et al. A comparison of the specific heat values for FJS-1 and JSC-1A revealed significant discrepancies even though both of them simulate mare regolith. In this study, the accuracy of specific heat measurements was first validated using single-crystal silicon with temperature-modulated differential scanning calorimetry (TM-DSC). Then, the specific heat of FJS-1 and JSC-1A was measured using both TM-DSC and the adiabatic continuous method. As a result, the specific heat values for FJS-1 and JSC-1A obtained using the two methods were consistent. It was also found that the specific heat of the two simulants was nearly identical within the tested temperature range. This consistency suggests that the specific heat values obtained by TM-DSC are reliable, as there is no significant difference in the specific heat of FJS-1 and JSC-1A.
