you need gas plasma, and electric current
and a lot of techknowhow<p><a href="https://en.wikipedia.org/wiki/Plasma_propulsion_engine" rel="nofollow">https://en.wikipedia.org/wiki/Plasma_propulsion_engine</a><p><a href="https://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket" rel="nofollow">https://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magn...</a><p><a href="https://en.wikipedia.org/wiki/Plasma_(physics)" rel="nofollow">https://en.wikipedia.org/wiki/Plasma_(physics)</a><p>at this point in the game it looks like a cylinder of compressed gas