Slipstream engine
From Tardis Wiki, the free Doctor Who reference
Slipstream engines are a form of faster-than-light travel utilised by the Raxacoricofallapatorians of Raxacoricofallapatorius. (DW: Aliens of London)
Little is known about the engine but it can probably allow access to hyperspace. Slipstream engines may also be used in starships of the inhabitants of Clom, Raxacoricofallapatorius' twin planet.
