The Aberdeen Proving Ground is a field of space in the Florida system controlled by the Liberty Navy. It is mostly empty, however bouys, dummy ships, weapons platforms and more are often placed here and moved around. It stretches north to the Battleship Alabama and south to the Biscayne Cloud, where nebula combat tactics are practiced.
The purpose of the Aberdeen Proving Ground is as a training area for Navy pilots graduated from West Point. Military exercises were once practiced there, until the leadership of the Navy determined West Point to be too public for their training procedures, which are sensitive by nature, to occur.