Saucer separation

In the fictional Star Trek universe, saucer separation is the term used to describe when the saucer section on certain types of Starfleet starship disengages from the stardrive section. This was first employed on the show in Star Trek: The Next Generation's opening episode, "Encounter at Farpoint, Part I", and was subsequently employed in later episodes and movies.

Some Starfleet starships such as the Galaxy Class starships consisted of two sections: the stardrive section, where the warp engine and battle bridge are located, and the saucer section. In times of battle, it was intended that the saucer section of the ship would separate from the stardrive section of the ship. Carrying all the non-essential personnel, this section could travel away from the battle, while the more powerful stardrive section could engage the enemy in battle. If the outcome was successful, the two sections could be rejoined.

Not all Starfleet ships of this shape neccessarily have saucer separation capability.