Pre-Launch Assembly, Integration, and Testing Strategy of a Hyperspectral Imaging CubeSat, HYPSO-1

Round 1

Reviewer 1 Report

Review of "Assembly, Integration, and Testing Strategy of a Hyperspectral Imaging CubeSat, HYPSO-1" by Prentice et al., submitted for publication to Remote Sensing.

 

The authors describe the process of design, construction, integration, testing, and deployment, of the HYPSO-1 CubeSat. They do so by describing the main challenges, pitfalls, lessons learned and successes that led to the launch of the cubesat which is looking likely to achieve mission success. The manuscript is written in a way that is very detailed, descriptive and thoughtfully connected. It is informative and a very entertaining read. I have no doubts that the manuscript will serve both as a guiding document for the internal development of future missions at NTNU, but also to other entities trying to get into the construction of cubesats. I recommend publishing the text in its current form.

 

Minor: Line 909 should read "been" instead of "be"

Author Response

Thank you very much, we also hope it will be helpful to other teams! The spelling mistake has been corrected.

Reviewer 2 Report

1) the title must be correcting as the article is more about ground testing infrastructure

2) Hyperspectral measurements are indicated in the title of the article, but there are no characteristics about the device, except for technological ones, which are only indirectly related to the measurements themselves and the need for the device. The task of the space hyperspectral device is to obtain data through measurements of reflected solar radiation with the required accuracy, the correct position of the device to the object of study with the necessary technical parameters (time intervals, spectral range, etc.). Now the article shows only the appearance of the device and describes its structural details, which are associated with technical parameters, but do not determine their value.

3) If the volume of the apparatus is chosen as 6U and the article describes the nodes that fill its space, however, without indicating how important this is for obtaining measurement accuracy, tuning accuracy to the object under study, data transmission to the ground, etc.

4) When testing for vibration of a spectral device, it is not clear (not presented in the article) which environment is the test, judging by the spectrum in Fig. 12 located on the right.

5) Why the authors describe the role of students and the team in solving the problems of forming a spacecraft with a unique device is not very clear, since the functional part of the work related to the use of the data obtained is not presented. After all, this is what the spacecraft is intended for, namely, obtaining high-precision data, for which georeferencing in place and time is possible.

Author Response

Thank you for the critical assessment and constructive feedback. We hope you find that the revisions address the topics mentioned. See our specific responses attached for more explanation. In the latest uploaded version, you will find additions / modifications to the manuscript in blue.

Author Response File: Author Response.docx

Reviewer 3 Report

This paper describes thoroughly the process of designing and developing a CubeSat for a scientific mission, focusing specifically on the assembly, integration and testing strategy adopted in the process.

The paper is exhaustive, and I think the content will be of interest to other CubeSat developers.

My specific comments are as follows:

1) The authors do not show a table of the time taken to develop each subsystem. They show a schedule, but it is not refined in a way that can be helpful to other teams. I suggest to go one level deeper.

2) How many iterations did it take to design and achieve a successful outcome for each module? This will be helpful to other teams.

3)  I think it would be helpful to discuss and show the electrical subsystems and how they integrate. This is usually a very engineering intensive part, and it would be nice to know. How did the individual boards interface, what basic processor setup was used, and how did the boards communicate with each other?

4) What was the ground communications setup, and what data rate is expected to be achieved, i.e. transmitted to ground? What is the groundstation coverage?

5) In my opinion, there are three very important components of the system level design: the Concept of Operations, the power budget, and the link budget. These tend to determine and specify the satellite. I think the authors should discuss these items.

I realize the paper will end up being even longer, but I do think the above recommendations are on point.

 

Author Response

Thank you very much for the critical assessment and constructive feedback. We hope you find that the revisions address the topics mentioned. See our specific responses attached for more explanation. In the latest uploaded version, you will find additions / modifications to the manuscript in blue.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

Paper is much improved. It is now ready for publication in this reviewers opinion.