The Yoyodyne pulse fusion reactor is a type of engine utilized by DY-500 class starships during the earily 22nd century. (TNG: "Up the Long Ladder")
- This "drive type" was described in an Okudagram that appeared in the episode and may have been designed or constructed by the group later descibed as the Yoyodyne Propulsion Systems. The use of the term "Yoyodyne" is a "in-joke" references to the 1984 cult classic sci-fi film The Adventures of Buckaroo Banzai Across the 8th Dimension.