Solar wind

Solar wind was charged particles emitted by stars. They could be used to travel through space, pushing an object along like a sailboat.

The ships in the race for Enlightenment travelled by solar winds. The Buccaneer was designed to be able to move in the slightest breeze of solar wind. (TV: Enlightenment) The Veltrochni Dragon cruisers also travelled by harnessing solar winds. (PROSE: The Dark Path)

The Isolus naturally travelled through space via solar winds. (TV: Fear Her)

Eldrad developed spatial barriers to shield his homeworld, Kastria, from solar winds. He destroyed them when King Rokon denied him his plans for galactic conquest. Eldrad was sentenced to death but, due to fears that control between Outer Dome Six and his obliteration module would be severed as a result of solar winds, the ship was detonated prematurely.

The winds left Kastria desolated and the Kastrians, in Rokon's words, "chose final oblivion" rather than face life in the subterranean thermal chambers. (TV: The Hand of Fear)