"Sublight propulsion," Dahak went on, ignoring the interruption, "relies upon phased gravitonic progression. Your present terminology lacks the referents for an accurate description, but for purposes of visualization, **you may consider it a reactionless drive with a maximum attainable velocity of fifty-two-point-four percent that of light.** Above that velocity, a vessel of this size would lose phase lock, and be destroyed.

- Mutineers' Moon, Chapter Three