Passive Thermal Control Design Methods, Analysis, Comparison, and Evaluation for Micro and Nanosatellites Carrying Infrared Imager

Round 1

Reviewer 1 Report

The manuscript entitled “Passive thermal control design methods, analysis, comparison, and a review for micro and nanosatellites carrying Infrared imager” (corresponding author S. Selvadurai) submitted for reviewing and publication to Applied Science addresses the question of passive thermal control for small satellites using thermal straps, multi-layer insulation and radiators. The works aims to provide a design for an infrared imager in function of the satellite orbit and space environment. The manuscript provides discussion of various passive cooling methods and addresses experimental characterization of thermal straps, simulations for a passive radiator and various elements for thermal design of 6U satellites in function of the satellite’s environmental heat load and trajectory. The manuscript doesn’t provide enough references to situate the work in the relevant field of studies and the research design is not clearly presented. I recommend to reconsider the publication of this manuscript in the Applied Science review after resubmission of a major revised version.

 

In the case of resubmission of a new version of the manuscript, please take into account primarily the following suggestions:

 

• Add more references to the literature in order to indicate the research that was already done on thermal control of satellites and to situate your work within this field
• Check that all quantities involved in the equations presented in this manuscript are clearly defined
• Provide concise and precise descriptions for the experiments and for the design simulations and ensure English proofreading of the submitted manuscript

 

Here is a list of minor corrections that are suggested:

 

1. in the title of the manuscript, replace “Infrared” with “infrared”
2. in eq. (1) and lines 42-44 there are many typesetting errors (Q is used instead of E, many numbers appear in normal type fonts instead of superscripts) and the quantity T is not defined
3. for the detector temperatures indicated in Table 1 please indicate references to relevant literature describing such detectors
4. define all quantities that are used in eq. (2); fix one notation in the manuscript for the emissivity e_eff / e*
5. line 105 : define the notions of solar absorptance (α) and emissivity (ϵ)
6. define all quantities indicated in eq. (5) 
7. don’t use additional numbering for only one sub-sub-section “3.3.1. Thermal Straps Conductance Characterization”
8. line 141: explain the performed experience more precisely than “A Minco HK6903 is used for this test.” Indicate precisely how the heat loads are generated and how are measured the temperatures and if it is any dependence with time in the heat transfer phenomena.
9. line 148 : describe what kind of devices are the P104 connectors
10. line 150 : the dimensions are not indicated in Fig. 3, contrary to what is indicated in the text;
11. line 151: why do you have a small dependence of the conductance in function of the heat flux?
12. below line 166 : define the quantity S/C radiator; use the same unit Q_rad and f_e; fix typesetting error Qrad; use Q_rad instead of Q; typesetting error in naming “Stephen” instead of “Stefan”; provide the value of the Stefan-Boltzmann constant
13. define the quantities Q_in and Q_out used in eq. (8)
14. use the same notation for Q_internal in eq. (11), eq. (12) and the definition at line 157
15.  eq. (13) is wrong and Q_absorbed is not defined
16. fix notations Q_w and q_w in eq. (14)
17. line 164 : wrong reference to eq. (17) instead of eq. (14)
18. lines 165-167 : specify the relevant order of magnitude for these quantities in order to verify that the approximation indicated is suitable
19. in Fig. 7 put into the legend the unit of temperatures and display 228K…288 K
20. line 197: the comment is valid only for Fig. 8
21. line 226 : provide full information on the reference indicated (Mackay and Leventhal et al)
22. explain the physical mechanisms that lead to the dependence shown in eq. (15); after eq. (15) use the same notation q_actual in the manuscript
23. define the quantity b that is used in eq. (16)
24. on Fig. 10 it may be useful to indicate the different parts that are discussed in the text of the manuscript
25. in legend of Table 3 indicate instead “6U and 27U satellites”; set clearly in the body of the manuscript if these numbers are taken from the literature and reference the relevant publication or this is a proposal for the design of a new satellite
26. lines 251-253 : indicate on Figure 11 the beta angle and the orbital angle
27. : define W, G and e’ angles that are used in eq. (19) and plot them on Figure 11
28. Contrary to the title “3.4.4. Thermal analysis and Results”, no results indicated in this section
29. line 349 : indicate the meaning of the abbreviation CCHP and describe it adequately
30. line 352 : provide full description for the heat pipes and the condenser evaporator
31. on Figure 16 indicate the thermal exchanges between various parts, and refer to the relevant parameters
32. Figures 17-19 are not commented in the text and the simulation results are just briefly addressed
33. line 374 : indicate dimensions of the thermal strap
34. line 395 : In figures 22-25 a parameter that varied is the radiator area. The beta angle is the same for all plots? Indicate also the value of the beta angle. It is not clear why the shapes of the curves are different (flat vs. parabolic)
35. line 396 : precise “as described in figure 10” if you are referencing to figure 10

Author Response

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Reviewer 2 Report

Review for manuscript, title:

A Passive thermal control design methods, analysis, comparison, and a review for micro and nanosatellites carrying Infrared imager

The article is devoted to an important issue –the performance of thermal straps, surface coatings, Multi- Layer Insulation, and radiators for a 6U small satellite configuration carrying a Mid-Wave Infrared payload whose temperature needs to be cooled down to 100K.  Moreover a comprehensive review of all the passive control methods to meet payload thermal requirements are presented in the article.

Introduction is devoted to the questions of New Space approach. Moreover the purpose of the article is shown here, but it’s only about  the consideration of  a Mid-Wave Infrared (MWIR) instrument whose detector is required to be maintained between 0 to -100oC for a few specific missions.

So it’s can be better if the introduction will include all questions which are in the abstract (line 15-16, for example).

Materials and Methods

It’s will be better to make a chapter  « Materials and Methods», which could include points 2 and partially 3.

it is advisable to single out the results section separately

 

 

 

Author Response

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Reviewer 3 Report

In the abstract, the authors used the expression (This paper tries). I think it is an odd expression. Please rephrase it. 

The remaining parts of the abstract are well-written as they briefly describe the problem, objectives and aims.  

Poor referencing is a major problem, especially in a review paper. 110 lines were written with only 4 references. Each provided piece of information shall be followed by a reference. This applies to the entire paper. Please revise.

While the paper has provided an excellent background, a critical review of the current state of the art was not provided. A famous practice of reviewing articles is through the advantage-disadvantage table. This was not presented in the paper.   

Overall: Major.  

Author Response

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Round 2

Reviewer 1 Report

The authors updated substantially the bibliography in the revised version of the manuscript and responded to all comments made by the referee. Some typesetting errors are still present in the manuscript. See, for example:

-line 220 : Q_IR is not defined

-correct typesetting of eq. (15), because this equation cannot be derived from eq. (14)

-undefined quantity F_v in eq. (15)

-table 3 : wall area : wrong symbol

-table 5: battery : wrong coating

-line 485 : Δ35°C of margin : use words not symbols in the manuscript    

-line 516 : wrong reference : figure?

-figure 27 and figure 29 are redundant

-lines 565 and 574 : degC is not a recognized unit

-for most of the new references added to the manuscript, please specify all information about them by using the MDPI style, not only the author and the title

I recommend the publication of the manuscript in the Applied Science review upon correction of these minor changes.

Author Response

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Reviewer 3 Report

The authors have addressed all my comments successfully 

Author Response

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