Steam engine powered uav? please mark interesting=D?

I suspect, that the efficiency of a modern jet turbine (or any internal combustion engine, as opposed to an external combustion steam engine) is alot better than a steam engine (in that size range in any case) not to mention the power availible compared to the m of the engine. Also I think desregarding efficiency or weight, I think it may be much easier to build a jet engine which has a higher power output than a steam engine of that size (to fit on a plane, as opposed to one which powers an electricity generating plant for example, which almost invariably use steam turbines). Plus a steam engine will need to carry water (or some other fluid) in addition to fuel.