I've lost the thread, but there was some debate earlier as to who actually created the death star...
From
http://www.starwars.com/databank/location/deathstar/
index.html
'The brainchild of Grand Moff Tarkin, the Death Star was developed in secret. Rebel Alliance spies were nonetheless able to learn of the weapon's existence, and stole vital technical schematics from guarded Imperial vaults. These desperate spies transmitted this data to Rebel leader Princess Leia Organa, who stored the plans in R2-D2's memory systems. '
So, according to this Tarkin was behind the death star. Obviously, what we saw in Ep. 2 contradicts this.