Terrestrial Ion Propulsion
Date: Summer 2013
I am very interested in space travel and I just found out that we can also travel with ion propulsion. So my question is can we travel on earth with ion propulsion or only in space?
The reason why an ion engine is not suitable for propulsion on earth is
simple. Ion engines produce only a very tiny amount of thrust. In space
where there is no resistance to motion, this is no problem. Although a
large ion engine may only produce a few newtons of thrust, the engine
can easily operate for weeks or months. Even though the resulting
small thrust results in an extremely small acceleration, in space where
there is no friction, weeks or months of this acceleration will eventually
result in very high spacecraft speeds.
But down on earth, where a moving body must overcome friction, a
thrust of a few Newtons wouldn't even start a vehicle moving!
Thanks for the question. In principle, you can travel on Earth using ion propulsion. However, when ions are exposed to air, they become neutralized and charge on them becomes zero. This results in a substantial decrease in propulsion and the propulsion energy is wasted as heat. Furthermore, the ion source (containing a red hot wire which generates ions) will be destroyed when it is exposed to air. It is much like a light bulb burning out. Ion propulsion works in space since there is no air to interfere.
Click here to return to the Engineering Archives
Update: November 2011