Question: Ships leaving the Void

Assuming a ship does not want to decelerate and stop in a system how close can they drop out of the Void near a planet? Is there a minimum safe distance?<br />(I'm writing an article about faster than light torpedoes. The idea is they are launched from one system to another, drop out of the Void and hit a target before the target can react.)<br /><br />Side note; remember the worm hole that was created when Capt. Kirk went to warp speed before clearing the solar system?