Ion engines have been around in sci-fi as far back as 1947, in Equalizer, by Jack Williamson. NASA has had ion drives for some time now, but they aren’t quite as impressive as those on the Galactic Empire’s signature Twin Ion Engine Fighter, pictured above.
Ion drives work by ripping electrons out of a gas like xenon, then passing the charged particles of gas through a magnetic field to speed them up and fire them out as propellant.
The beauty of ion propulsion is in its efficiency.
While a spacecraft flying with ion drives alone would accelerate very slowly, it would also use a lot less fuel than a chemical rocket. This means that even a small spacecraft can keep running, and keep accelerating, for quite a long time. It’s very possible that future manned missions will use a combination of chemical and ion drives as we set out to colonize Mars and explore the rest of our solar system!