The grain size distributions of the three Mars regolith simulants have been added to the text in form of two additional tables (table 2: P-MRS and S-MRS; and table 3: JSC Mars-1A), as well as a new citation for the grain size distribution of JSC Mars-1A [8]. To assess the shading effect of the regolith is difficult. As described we used a very thin layer of regolith particles, but did not measure them according to their shading effect but according to the weight, which was the same for all types of regolith. This experiment was meant as a test of the sterilization method adjusted to our purposes, as described in the introduction section. Therefore, we did not plan it according to the maximal theoretically achievable sterilization effect, but to design a life detection mission to Mars. [8] Wan, L., Wendner, R., & Cusatis, G. A Novel Material for In Situ Construction on Mars: Experiments and Numerical Simulations. 2016, arXiv preprint arXiv:1512.05461
The authors should have estimated the maximal theoretically achievable effect and to plan the experiments accordingly.