Reliability Assessment of Space Station Based on Multi-Layer and Multi-Type Risks

Round 1

Reviewer 1 Report

The authors conceptually develop a new method for reliability assessment through the multi-layer and multi-type risks for space station configuration mission in the early stage. All the aspects which are presented in the paper are defined generical, having in mind the complex field of research. A lot of terminologies and definitions are presented in the paper, see chapters 2 and 3. These come to clarify the paper subject. An interesting scheme, Figure 1, for identified the space station reliability components is presented. Then a space station configuration risks are proposed, Figure 2. They identified 457 risks for the space station configuration using the multi-layer and multi-type risks identifications combine with preliminary hazard analysis PHA and system hazard analysis (SHA) methods. Details of these risks are presented in Table 1. Risk feature qualitative analysis and risk feature quantitative analysis are analyzed and are summarized in Tables 2-4. An evaluation risk matrix is developed which gives the possibility to determine all 5 levels of configuration risks. A Reliability model of space station configuration, which includes 3 phases and 4 states, is presented. All data are computed with a dedicated software IQRAS. A reliability model is built, and the Figures 5-8 present the initial event mission begin and the pivotal events KTV, MML and AC. For the reliability assessment, a mathematical model for the occurrence probabilities and propagation probabilities is presented synthetically. Finally for reliability assessment of space station configuration mission, the LOC state has the highest state probability, and needs to be analyzed carefully. The paper has an original topic, and the authors opens new frontiers in research. The paper is very well structured, and the subject is very well developed. The conclusions are clear. The paper can be published in the present form. 

Author Response

Dear Reviewer,

  Thanks for your review. I accepted all your comments and implemented them in the revised version. 

Author Response File: Author Response.docx

Reviewer 2 Report

Dear authors,

I appreciate the attention to detail in the writing and how well organised it is. It makes it very easy to read and understand.

I just wanted to point out that some figures would require the size of the letters inside to be larger: from figure 5 to 9. 

Best regards,

Author Response

Dear Reviewer,

  Thanks for your review. I accepted all your comments and implemented them in the revised version. And the followings are the modification notes.

(1) All the figures in the paper have been improved for their letter sizes and colours. 

Author Response File: Author Response.docx

Reviewer 3 Report

1. Figure Presentation of the paper has to be improved. Figure 1,2,3,5,6,7,8,9 are too small and hardly can make up what is representing.
2. For figure 3, might be better to use bracket for percentage. It looks to be a little confusing with the number and percentage together initially.
3. Line 223 to Line 228, please check the figure labelling spacing.
4. Table 5 can be better presented.
5. In chapter 7, the explanation of the result is not clear and too brief.   

Author Response

Dear Reviewer,

  Thanks for your review. I accepted all your comments and implemented them in the revised version.  The followings are the modification notes of the comments.

(1) All the figures in the paper have been improved for their letter sizes and colors.

(2) Fig. 3 has been cancled becaused of display effect.

(3) LIne 223 to line 228's figure labelling space has been checked.

(4) Table 5 has been improved.

(5) Chapter 7's result explanation has been improved according to the PRPA main process.

Author Response File: Author Response.docx