I have 50 floors so far, and I have noticed that the green death star hologram behind palpatine keeps growing in size as I build up my death star. Does this happen because I do palpatine's missions or because I build up more levels? And is there an end to palpatine's missions? Will it end when the death star hologram behind him grows full?
In my case I built all the Service floors, and now Palpatine wants me, according to his genius "plans", to build one more, which is kinda impossible for now... Palpatine's always full of surprises. ;)
So this let me believe he will always summon up new missions randomly. Until you ran out of bux trying to skip the impossible ones.