Out of curiosity, I decided to do some investigation into the properties and function of ions and ion thrusters. In simple terms, ion thrusters are employed for low power course corrections and orbit maintenance for satelites.
One thing that stood out was that ion thrusters function best in ion-free environments, such as the void of space. So I started (brief) research into ion saturation in earth-like atmospheres, and stumbled upon greenhouse gasses. Greenhouse gasses, particularly the water vapor within them, are saturated with ions. This would suggest ion thrusters would function sub-optimally on "jungle" worlds.
EDIT- Mercury, Venus, and Titan also have ion-saturated atmospheres.
Now I know SW is science-fantasy, and I'm perfectly within GM fiat to say (or assume) ion thrusters simply function as a matter of course, but I'm looking for an alternative thrust option for ships while in atmosphere.
Examples of ion fuel are:
Ionization energy represents a very large percentage of the energy needed to run ion drives. The ideal propellant for ion drives is thus a propellant molecule or atom that is easy to ionize, that has a high mass/ionization energy ratio. In addition, the propellant should not cause erosion of the thruster to any great degree to permit long life; and should not contaminate the vehicle.
Many current designs use xenon gas, as it is easy to ionize, has a reasonably high atomic number, an inert nature, and low erosion. However, xenon is globally in short supply and very expensive.
Older designs used mercury, but this is toxic and expensive, tended to contaminate the vehicle with the metal and was difficult to feed accurately.
Other propellants, such as bismuth, show promise and are areas of research.
Anyone have some suggestions for liquid/solid fuels for mass reaction, for thrust within an atmosphere's envelope? I think it's worth considering, given some GMs/play groups track fuel (at least for refueling costs), and it can add a level of technical gizmoism to tech-minded characters.
Electrostatic Ion Thruster: http://en.wikipedia....:Ion_engine.svg
Electromagnetic Ion Thruster: http://en.wikipedia....ll_thruster.svg
EDIT- Mercury as an ion fuel puts me in mind of the possibility of some alien cultures utilizing "dirty" ion engines. Basically toxic-emissions thrusters that might result in higher docking fees/taxes.
Edited by Brother Orpheo, 01 March 2014 - 05:10 AM.