Another way to make drones... is to put human-like robots at the controls. The same aircraft can be used by flesh-rich organic beings and hard-skin guys. Of course, humans need oxygen to breathe, and mechanical beings only need toxic monopropellants to feed his internal generator.
Of course, the added ventral engine is not a conventional turbojet. This aircraft, version "L" in the large Cu-175 series, is propelled by a twin-burner camera motorjet, in that an opposed-piston, two-stroke Diesel engine drive twin radial compressors and each compressor feed a burning camera. Adding to this, the "L" version have an independent turbojet in that the axial compressor is driven by a steam turbine that is feed not by the hot gases of the already mentioned piston engine, but by the catalytic decomposition of Hydrogen Peroxide in three reaction chambers, generating an stream of oxygen-rich hot steam that drive the turbine and discharge in the rear burning camera. The compressed air is ducted to a rear burning camera that discharges hot gases through a nozzle, without any turbine disc in between. An engine like this was designed and constructed by Hellmuth Walter of Walter-Werke in Kiel during the World War II.