Dummies do not detect. Detection occurs at the end of movement, but before combat. Overloads, Refueling, and Repair Packets may undergo one overload maneuver, and then require minor maintenance. The same is true of Imperial ships in the basic game. Combat Imperial corsairs carry one mine each, which may be replaced by rendezvous with an orbital base.
Imperial bases are detection stations only, with no combat strength.
Course of the Game Imperial units begin the game motionless, and may not move until at least one packet is detected. They may not attack, or deliberately move toward, an undetected packet. However, a packet may maneuver to avoid any Imperial unit, detected or not. This will itself allow fuel to be burned, letting the Imperials detect the ship, but can be worthwhile. The game ends when no packets are left on the board.