An Adaptive Approach for Impulsive Formation Maintenance Relevant to Distributed SAR Missions
Round 1
Reviewer 1 Report
The paper proses an impulsive reconfiguration algorithms for a distributed SAR-like mission. Although the paper is not very original in the content, it is well written and presented. Please find my comments in the attached document.
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
Performance assessment of an adaptive approach for impulsive formation maintenance in distributed SAR missions.
Strengths:
The paper presents a clear approach for safe formation maintenance under tight constraints. The approach is easy to understand is demonstrated on a relevant problem / dynamics environment. I recommend publication after minor revisions that are intended to further improve the paper's clarity and value.
Concerns and Suggestions:
(1) The title suggests that the algorithm will assess the formation's performance in the context of a DSAR solution. The problem parameters are inspired by DSAR applications, but the resulting DSAR performance is never directly assessed. I would suggest that the title be modified to be "An adaptive approach for impulsive formation maintenance relevant to distributed SAR missions".
(2) Can the commanded transfers violate the safety tube? If so, it is worth noting. That means that the formation is at risk of an erroneous delta-v. And perhaps it would be future work to consider adding a constraint to prevent that.
(3) I don't understand when/where the navigation errors are added to the states in the simulation flow. In figure 5, which boxes have the errors added? Perhaps it would be worth adding an input to the figure to show this?
(4) I would suggest that you annotate where Algorithm 1 and equations 2-4 are used in Figure 5. This could also just be stated in the text. In particular, it appears that the \Delta\delta elements in equations 2 and 3 are not part of the optimization software. That is, Algorithm 1 specifies a single unique set of \delta elements that the deputy should return to, and the optimizer is only finding the best pair of maneuvers (at which arguments of latitude and maneuver directions) to achieve that. Is that correct? This portion of the text might benefit from clarification.
(5) While the navigation errors are relevant and of value, I am also interested in the sensitivity of maneuvers to ballistic coefficient matching and maneuver execution error. While the nominal ballistic coefficients may be identical, what happens if one vehicle needs to adjust its attitude or solar arrays relative to the other vehicle? (Perhaps the vehicle maneuvering needs to adjust its attitude to execute the maneuver). For maneuver execution error, I'm concerned that a spacecraft will not be able to accurately deliver a ~1 mm/sec maneuver. In my limited experience, this is well below the minimum impulse bit of a single thruster. For this application, you would select appropriate thrusters, but what is the requirement for their accuracy? For example, what is the effect of a 5% (1-sig) magnitude error? If it is reasonable to add these analyses, the paper and reader would benefit.
(6) I'm not sure that having tables 4 and 5 add substantial value. The same results can be viewed in Figure 8. Personally, I don't think that the reader benefits from having the increased precision since the scenario is so specific.
Minor comments/suggestions
(7) In lines 273 and 281, "e" is used instead of "and".
(8) On lines 279, 322, and 375, I would suggest removing the word "instead".
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
