Gosh, if only there were possibilities beyond chemical and electric . If only...
In the context of this discussion, there isn't any. Because if there is a new physics discovery or game changing technology, it is likely that the financial resources of gov'ts are not needed.
Does this make sense to you? Really?
Kinda curious if that makes sense to anyone else, because it sure doesn't to me. How can anyone actually believe that colonists on Mars or in the asteroid belt, whose lives and the futures of their children, will somehow restrict themselves solely to chemical or electrical propulsion systems, when they already have full knowledge of nuclear thermal systems, solar sails, magsails, electromagnetic coilguns, plasma thrusters and a whole bunch of other, better systems? Never mind more theoretical systems like nuclear pulse, fusion rockets and such?