Ordinarily, combustion rockets and nuclear-electric rockets are considered as mutually exclusive categories. Would it be possible to have a launch vehicle engine which benefits from characteristics of both? For instance, chemical combustion generates a lot of kinetic energy from heat, and yet that energy is so chaotic that not all of it is harnessed as thrust. Meanwhile, ion and plasma engines are much more efficient, yet their thrust is low. Could it be possible to take the already hot exhaust gas produced from a combustion chamber, and either ionize it or break it down into plasma, in order to further accelerate it linearly using electric coils? The energy to ionize or "plasma-ize" exhaust gases would be supplied by a nuclear reactor which would supply energy for high-powered microwaves and magnetism to convert the hot combustion exhaust into ions/plasma. The ions/plasma would then be accelerated electromagnetically (Lorentz force?) http://en.wikipedia.org/wiki/High_Power_Electric_Propulsion I guess the overall goal here would be to have the high thrust of a chemical rocket, while boosting the Isp using nuclear power. (Yes, I've been previously reminded me that reactors require shielding, but let's assume this is an unmanned cargo rocket for the sake of argument) There are various designs for nuclear-enhanced chemical propulsion which have already been proposed, but most seem to involve using the nuclear reactor to increase the heat of the exhaust. I've not seen anything proposed which uses nuclear power for electromagnetic acceleration of the exhaust gas. What would be the pro's and cons of this idea?