Nobody knows quite why the Ugokin war started, but all attempts at finding a diplomatic resolution met with disaster. The war was proving long and bloody, and with the Ugokin almost never retreating, and self-destructing rather than surrendering, any victories came at a heavy price.
The first major break for the Federation came at the battle of Solice IV. Although hardly more than a skirmish in militaristic terms, it was the capture of a Ugokin "Hunter" class starfighter intact that allowed Federation scientists to decode secrets about the Ugokin spacecraft that are still classified today.
LL-451 "Manta" class carriers played a vital role in the battle, deploying their LL-109 "Mosquito" fighters to isolate and overcome a Hunter. It was LL-451 that carried the captured Ugokin ship back to Federation scientists for analysis. And what did they discover about them? We'll have to wait for the files to be declassified to find out!