Sprit

From Memory Alpha, the free Star Trek reference

A sprit is a component in a Bajoran lightship. They, along with the other sails, capture ions in order to propel the ship.

During his voyage to prove lightships were spaceworthy, Benjamin Sisko was forced to jettison a sprit from his lightship after the mast support gave way. This dampened his spirits, but Jake urged him to push on. (DS9: "Explorers")