Ceramics—The Forgotten but Essential Ingredients for a Circular Economy on the Moon

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This review systematically demonstrates the indispensable role of ceramics in the lunar circular economy. It highlights that current technological pathways—particularly polymer-dependent 3D printing—are constrained by the scarcity of surface carbon resources. Resolving this bottleneck is proposed as a critical prerequisite for lunar industrialization. This article provides significant insights for lunar in-situ resource utilization (ISRU).

The impact of this work could be further enhanced by addressing the following points:

1. Reports from China’s lunar program indicate that the Chang’e-8 team is scheduled to use optical components to concentrate solar energy, generating temperatures exceeding 1400°C to melt lunar soil for 3D-printing construction bricks. (https://www.scottishconstructionnow.com/articles/and-finally-china-plans-to-3d-print-bricks-on-the-moon) Please discuss the feasibility and potential challenges of this approach.

2. Rare earth elements serve as effective additives for ceramic by inhibiting grain growth, promoting densification, and enhancing mechanical properties. With reference to recent studies (http://dx.doi.org/10.1016/j.jeurceramsoc.2024.04.026; http://dx.doi.org/10.1007/s10853-024-10569-9), please discuss the utilization of lunar rare earth resources in ceramic fabrication.

3. Carbon is a critical resource on the Moon. While the authors outline pathways for carbon extraction and utilization, a deeper analysis is suggested regarding energy consumption, requisite equipment, and carbon source utilization efficiency.

4. Minor errors require correction, including the duplication of References 22 and 25, and the formula "La2O2" in line 287, which should read "La2O3". Please conduct a full-text review and revise accordingly.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In general I quite liked this paper. However, it is missing a couple of things, in my opinion. First, while the elemental data used is fine, given the structure of the paper, including the mineralogical composition of the lunar regolith needs to be done. McKay et al. in Chapter 7 of the Lunar Sourcebook contains some of this material, and Papike et al. https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/RG020i004p00761 has a good description in their Table 12.

 

With this information, a water balance for the reactions proposed for the ceramics is necessary as the amount of water is not known very accurately and human uses would come first.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

1. Please add some typical figures into your review. For a good review, suitable tables and figures are essential.
2. Please classify the material types.
3. Potential advanced manufacturing technologies for ceramics used in space are suggested to review.
4. Economy analysis is missing.

 

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

This is an excellent paper worthy of publication.

Reviewer 2 Report

Comments and Suggestions for Authors

I believe the additions made to the text have significantly enhanced the document. While I think the water balance would still be useful, in retrospect this is a large undertaking that would require considerable work and may be a full paper in its own right.

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have addressed my comments well. The revised manuscript is recommended for acceptance in its current form.