Orbit-Injection Strategy and Trajectory-Planning Method of the Launch Vehicle under Power Failure Conditions

Round 1

Reviewer 1 Report

In this work, the problem of autonomous decision making and trajectory planning (ADMTP)  for launch vehicles under power failure conditions, the target degradation order strategy (TDOS)   and the trajectory online planning method is considered.  Then, the launch vehicle  motion model under power failure conditions is given, and the influence of power failure on the  orbit-injection process is analyzed, In this context,  the TDOS is proposed according to the mission attribute, failure mode, and multi-payload combination.The optimal orbit-injection samples and online guidance instructions, and the RBFNN is used for orbit-injection samples training and online generation of orbital missions.  Also, simulation analysis  is performed under multi-failure conditions. The results show that the TDOS proposed in this paper can meet the requirements of the mission decision-making under different failures, target orbit types, orbit-injection methods, and payload compositions.

Some results obtained in this work are novel. The level of difficulty and originality of these results makes them suitable for publication. The experts in this field of Space missions  will appreciate some technical progress exposed in this work. Furthermore, the work falls in journal Scope.  In conclusion: this work provides theoretical support for autonomous decision-making and planning of space launch missions. However, some minor comments

• The abstract must be concise and includes only new results.
• The introduction: I think that it must be improved to shed light in earlier work
• 1 must be constructed or quoted the references (the authors have to follow this style related others equations and relations)
• The legends in some figures are not clear
• I think that the equations should be written with the editor equations style no description style.
• Try to write the second sub-equation 14 by proper way

In general, the authors have to describe in more detail the purpose of their study and its original contents. A clear explanation, what is the new result in their work, and how it is build up upon previous work in the field.

If the authors submit a modified version according to my suggestions where they also give more details/explanations about the abovementioned remarks, I could recommend the paper for publication in Aerospace.  

Author Response

First of all, we would like to thank the experts for their comments. Due to many modifications, please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

There are aspects that are worthy of publication, however, this paper requires a major attention and careful considerations. There are several things that need to be clarified.

1. The advantages of the proposed method of this paper should be more highlighted.

2. Present a qualitative and quantitative comparative analysis of the proposed scheme with its conventional counterpart.

3. Kindly enrich the literature review of this paper by citing additional references related to the topic addressed, particularly on fault detection approaches, influence of disturbances, modeling errors, various uncertainties in the real systems. A relevant recent review are: Asynchronous Fault Detection Observer for 2-D Markov Jump Systems, IEEE Transactions on Cybernetics; Iterative learning control for repetitive tasks with randomly varying trial lengths using successive projection, International Journal of Adaptive Control and Signal Processing; Data-driven control of hydraulic servo actuator based on adaptive dynamic programming, Discrete and Continuous Dynamical Systems - Series S. More generally, these reviews showcase the vibrancy of this field of research and should promote reading across fields. In this sense, also due to generality, it is necessary to comment what would be changed in this case and make relation with the papers on this topic in Introduction section, and in that way, point out other contemporary approaches and possibilities. 

4. Authors should clearly define what quantities must be specified to begin the algorithm. Did the authors consider how many initial conditions affect the outcome?

5. Authors should argue their choice of the performance evaluation indicators.
6. How about the complexity of the proposed approach? Please give some analysis.

Author Response

First of all, we would like to thank the experts for their comments. Due to many modifications, please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

In this paper, the authors propose online strategies for a mission recovery in case of contingent launch vehicle engine failures. The strategies are based on degradation rules for different target orbits and the online neural-based system that maps the description of the situation into the new target orbit parameters. The paper is well-written (though, editing is needed to correct commas and capital letters in some places), have a novelty and a detailed description. I recommend accepting the paper for publication.

Author Response

First of all, we would like to thank the experts for their comments. The authors have proofread the punctuation and letters of the full text according to the comments.

Author Response File: Author Response.docx

Reviewer 4 Report

The paper summarizes the problem of autonomous decision making and trajectory planning for launch vehicles under power failure conditions and how target degradation order strategy (TODS) and trajectory online planning methods could be used to provide support for autonomous decision making and planning of space launch missions. It is noted that power system failures have become the main cause of launch vehicle mission failure. The results from the authors show that the methods proposed can be used to meet the requirements for different missions and failure scenarios. The article is well-written and easy to follow. 

I recommend publication after addressing some minor points. Specifically, I would have liked to have seen more discussion of the results in the results section; there are numerics discussed in the abstract that aren't explicitly talked about in the results section. In addition, there are a few more specific edits for the authors to consider:

-Line 373-379: The sentences are fragments. Needs to revise.

-Line 416: Did you mean Figure 7-Figure 11? If not, then Figure 11 should be referenced in the text.

-Figure 7-11: I would have liked to have seen more discussion of these figures in the results section rather than just showing them. 

-Line 443: Capitalize Comparative

-Need to reference table 5 in the text

-For figures 12-17, I would have also liked some additional discussion in the text about these results, such as about differences seen in Figures 15 and 17 got the IV-PSO and failure IV cases.

 

Author Response

First of all, we would like to thank the experts for their comments. Due to many modifications, please see the attachment.

Author Response File: Author Response.docx