Hybrid, Prologue: The Last Battle
Like others have said before me, you've got a decent start here. It certainly gets the reader interested in what's to come in later chapters, so that's most certainly a plus. You drop the reader right into an interesting part of the story, as well, which is perfect for grabbing their attention right away and making them want to read on.
A lot of this piece was well done with flow for the most part, but there were some grammatical issues that stuck out when I was reading. Grammar and punctuation both are something with this I think needs some working on, but a few run-throughs with edits and I think you'll have a much more polished piece of work here.
There was also a lot of heavy/extended descriptions that could most definitely be cut. The first few paragraphs of description are really heavy with the information that is coming to the reader about the specifics and a lot of that can be done in a much simpler way without too much detail. Giving every distinct detail of the Spacers isn't necessary and it can bog down the writing quite a bit and lose the readers' interest. Due to this, there were also a lot of run-on sentences that I noticed (specifically towards the beginning) which can lose the reader in them.
Off of that, there were a lot of places throughout where there were needless words (adverbs especially) that could be eliminated to make the flow even smoother. I recommend reading it aloud to see what sounds right and what doesn't. The ear is always a better critic than the eye! If you find yourself stumbling over certain sentences when reading aloud or running out of breath reading them, etc., trimming is definitely something to consider. Every manuscript goes through a lot of trimming, and there's quite a bit here that could be taken out.
As for plot elements, I think you have a strong idea, but the world that you're creating just isn't fully formed on the page yet. You, as the writer, know your world like the back of your hand, but for the reader, this is new to us. Really get us to know and understand this world like you do. Ground us in it. Make us feel like we've been living there and are comfortable in how it works. You want to show your reader what your environment is like, and right now, with what little detail we do get, most of it is very telling. Show us (but remember to do so without extreme description like in the description of the Spacers). You'll be surprised how much more effective your opening becomes when you show and really get the reader grounded and invested in the world.
I think you're off to a good start, overall. You seem to know where you're going by this and what you want of the story, but it's still not on the page fully yet. Watch for grammatical and punctuation mistakes and remember to trim, trim, trim! Best of luck with revisions and the rest of your project!