Good story and characters, needs editing and fact checking
I like the story quite a lot. The characters are also decent. Those are the only reasons I made it all the way through. I would still recommend reading it if you like the genre, as it is a generally pleasant read and has some fun concepts.
That said, there are quite a few glaring issues. The spelling is fine, but the grammar is pretty rough in places. It needs some editing. The grammar issues really detract from the story at times and I find myself only skimming several paragraphs because they’re hard to read.
Some of the stuff mentioned is also just wrong. Like nebulae generally existing outside of a galaxy. There are clouds or lanes of gas and dust outside of galaxies, but they lack stars and are very diffuse. There can be star clusters that are fairly far removed from a galaxy and could be part of a nebula, but that would be rare.
Also, blue supergiants such as class class OB and class O stars generally only form in nebulae since they’re the primary spot to source so much fuel. Or they can form from other gravitational effects, but saying that it’s weird to see one in a nebula is wrong. This could be figured out in a quick search as well.
There are other examples, but these are the biggest sticking points for me. Otherwise it would definitely be a 5 star series.