ion propulsion: Meaning and Definition of

i'on propul"sion

Pronunciation: [key]
  1. a projected type of propulsion for vehicles in outer space, the exhaust consisting of positive ions and negative electrons repelled from the vehicle by electrostatic forces, resulting in a very high exhaust velocity.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.