I saw a post on Facebook asking how Federation ships can fly backwards using impulse engines, and it got me thinking about what the impulse engines are actually capable of. Memory Alpha states; "In Federation starships, the impulse drive was essentially an augmented fusion rocket, usually consisting of one or more fusion reactors, a driver coil assembly, and a vectored thrust nozzle to direct the plasma exhaust." That's pretty much how I pictured impulse engines. They are basically vectored rocket nozzles, but in orders of magnitude more powerful than basic chemical rockets. So, if that's the case; How can you reverse a ship using impulse engines? Does that ever happen on screen? How do you slow down from full impulse? Do you do a 180 and thrust retrograde? The RCS thrusters are obviously fairly powerful because they can land a ship on a planet, but are they powerful enough to do the above?