Star Wars: 10 Secrets Behind The Death Star You Didn't Know
8. Its Production Was VERY Classified
Obviously the Empire didn't want anyone to know that they were building such a monument of destruction, lest sympathy for the rebellion begin to swell across the galaxy, especially to those funding the project. As such, only the highest ranking officers knew what was planned.
According to the Death Star Databank on StarWars.com, it was kept such a secret that often even those on-board did not know the space station’s true function! Many were led to believe the Death Star was a mining tool and one its official designations within the galactic senate was "Imperial Planetary Ore Extractor".
If someone had just asked how exactly they were planning on extracting the ore from a planet, then maybe someone would have caught wind sooner.