When the Empire took Cassian Andor to Narkina 5 to serve his time, the camera panned over what turned out to be multiple prisons. Andor‘s prison arc showed groups of prisoners assembling hundreds of the same item. The guards emphasized quotas and overall urgency. But given that the Empire is, you know, evil, it was possible that the prisoners were building something meaningless. However, the prisoners assembled pieces for a critical project. The Andor season one finale post-credits scene showed where the parts Andor and his fellow inmates built went. The final image showed the parts the prisoners built snapping into place on the first Death Star.
The pieces from the forced labor camp specifically went to the Death Star’s superlaser array. This means Cassian contributed, albeit unwillingly, to constructing the weapon of destruction he would later go on to help destroy. It’s the kind of revelation that punches you in the gut. It does so even though it’s not terribly surprising that the parts went to the Death Star. You only have to think about the station’s sheer mass and when Andor‘s story takes place for it to make sense.
Attack of the Clones showed a hint of the project that would become the Death Star. The Geonosians called it the Ultimate Weapon project. After many years, the project took steps forward with Orson Krennic overseeing parts of the project, particularly the dish. Tarkin later took responsiblity for the Death Star along with Krennic, with some aspects of the battle station coming from the Tarkin Initiative.
We can’t wrap our heads around the labor and parts necessary to construct the massive station and weapon. The prisons on Narkina 5 likely represent a small number of the Empire’s facilities around the galaxy. In fact, the Aldhani robbery gave the military organization the excuse to step up punishment. In turn, the Empire got more prisoners for longer periods of time. The Empire needed bodies, by whatever means, to build the Death Star.