Longtime blogger friend, and about the only one I have left, Berthold Gambrel https://ruinedchapel.com/ has released an e-book on Kindle. I've always enjoyed his writings and he's graciously expressed his gratitude on his blog concerning my suggestions in his acknowledgments sections.
The setting is that after an interplanetary war The Directorate was created to preserved the peace and form a central government. A security force was created comprising members from all three planets. They reason that integrating all the planets soldiers this will ease the tensions brought about by the previous war. There's also a mega corporation that invented most of the technology making space travel and colonization possible that has become the controlling voice in the Directorate.
The protagonist is Lieutenant Gannon from Mars. She is in the guard in what is supposed to be a time of peace, but a faction known as Earth Firsters begin making trouble. They want Planet Rights!
At first there are small terrorist attacks that escalate to an attack on Mars. There are traitors that subvert the security from within, a bumbling bureaucracy slow to respond to an existential threat, a too big to fail corporation controlling the economy, and government, plus a kick ass hero.
The story is plausible because Berthold shows an understanding of human nature, knowledge of corporate greed, as well as engrained fossilized government stupidity.
To make the story work there is a lot of backstory to set the stage, but he breaks this up throughout the story so it's not like reading a history book. Berthold is not breaking new ground on the science as the technology is pre-Star Trek. This makes it more believable. It's fast paced and reaches a satisfying ending.
Now for the teacher in me to give advice. Ruined Chapel, accept it or reject it, but it is offered in the spirit of helping your writing to improve. You've grown over the past few years tremendously and this book is by far the culmination of your hard work on the craft. It will only get better.
Here goes:
1. Your villain and the terrorists. By telling the story from only Gannon's point of view, or that of narrator on the backstory the reader only gets a glimpse of why they are revolting. They're point of view needs to be given throughout the story. By the time the villain tries to recruit Gannon its too late. I think you realized this when you have him voice why he hasn't killed her. His answer is a bit lame. But if when they were on Mars and she was under his orders you switched to him and gave us his thoughts concerning her and wanting her on his side, maybe even a romantic interest he needed to suppress for the mission... Get my drift?
2. If your going to extrapolate from States Rights to Planet Rights you need to tell why they feel the Directorate has wronged them. You could include collusion with Luna and Mars instead of making it just spoiled grapes on the part of Earth. Even have Luna and Mars units in the revolt, which would make the villain's attempt at converting Gannon to the cause more plausible. You don't have to mention the students at this time.
3. The villain's answer to the students was to kill them. He explains what's happening. The theme here is great. By taking away Literature and history the Directorate is trying to make human robots. There's a reason why those two subjects are called the humanities. The all work and no play aspect could be expanded. After the battle on the space station you could have Gannon, knowing what the directorate is doing and wanting to change this in different way than extermination she could expound on how she plans to instill humanity into all the students.
4. By taking the student she's befriended to her home on Mars before reporting to Luna with her report. This is Gannon's first break with discipline and duty. After the surviving students are moved to Luna and her friend has learned more of what it's like to be human instead of programmed science geek, she can be the virus to enlighten the other students. Wow that's a whole new book. I hope I haven't jumped the gun if that's what you're already planning.
I know your baby is out in the world and it's hard to leave it and go on to another project. The beauty of e-publishing is that you can revise and correct if you're so inclined. My suggestions may help with future writings. I want to say again this a is a really really really good book. Well Done.
PS, I've submitted a review on Amazon, but it might not show up. You mentioned me in the book and when one of my reviewers I mentioned in another book his review of Optimus was removed. Amazon is getting picky on reviews.