What’s better than a jet engine? A jet engine with a rocket-powered exhaust.
Today’s invention is a hybrid rocket motor which can rotate around a pivot (blue) so that a cylinder lined with solid fuel is injected into the outlet from the jet.
This unit has an entrainment collar on the front so that air is sucked in and oxidises the rocket fuel.
This could be used to generate an enormous burst of thrust to escape when, say, being chased by a missile.