Fleet support
From VoidWiki
Every ship and station you construct requires a certain amount of void to support its maintenance, the Fleet support. Colony ships have much higher support costs than most other ships so keep an eye on income during the early colonising stages.
See Also: Taxes
Viewing Data
Empire -> Summary will allow you to set the tax level to increase income. Empire -> Income will allow you to view your income and upkeep.
Clicking on a ship, and choosing info will allow you to see the amount of void the ship costs per hour.
Exceeding Fleet support
If you ever run out of void, you will begin to randomly loose ships. How fast the ships are lost, and which ones is unknown except to the devs

