How to maneuver in space?

Everyone is familiar with spacecraft flying around in combat in the movie versions of Star Wars. They twist and turn and change direction almost instantly as if there is nothing to it, sometimes virtually defying the laws of physics.

NASA deals with changing the orbit of spacecraft in orbit around Earth and also on long journeys in the solar system. Basically, in order to change direction or orbit a spacecraft must use directional thrust. This is known in NASA jargon as Delta-V, which means a change in velocity usually in km/s or kilometers per second. Keep in mind that 1 km/s is four times the speed of a passenger jet. To make a 2 km/s change would require a massive amount of propellant, equaling the mass of the spacecraft or satellite. Also keep in mind that a satellite also is being affected by Earth's gravity and that a satellite's orbit has a perigee and apogee (it's in an elliptical orbit). I won't go into the complicated ideas of changing the orbital plane, the inclination, or changing altitude. I will tell you that in order to make a satellite fall vertically to Earth would require enough thrust to reduce the orbital speed to zero and this would take a Delta-V of 6.5 km/s. That would take a lot of thrust to do that. What it means is that combat maneuvers in space near Earth would require powerful rockets and lots of fuel.

Out in open space beyond Earth it's not all that easy to change direction quickly. It all depends upon the original velocity. My guess is that those TIE-fighters in Star Wars are traveling close to 3 to 4 km/s. Changing directions quickly would require lots of power. Those ships don't seem to have the size to hold a lot of fuel so they're using something more exotic. Wookiepedia lists them as having twin-ion engine power linked to a solar ionization reactor with solar array wings. Besides the engines, these fighters have awesome weapons that suck power. Basically, these machines are fictional and the technology is fantasy.

Lets say that a TIE fighter weighs about as much as an F15 jet fighter or 27,000 kilograms. So, in order to make a maneuver of a delta-V of 2 km/s in 5 seconds, this would require an acceleration of 2000 meters per second divided by 5 equals 400 meters per second squared. Then we take that and multiply it by 27,000 kilograms and we get 1.8 million Newtons. A Newton is the force needed to accelerate 1 kg of mass to 1 meter per second squared. This is the rocket thrust needed for such a maneuver. This is going to take one heck of a lot of rocket exhaust flow to achieve. The Saturn V rocket had 7.5 million pounds of thrust. We need 404,656 pounds of thrust for our calculation. We would need at least one of the Saturn V's first stage engines. The main problem is that this would gobble up fuel like an entire track full of drag racers.

Fighter jets are able to do quick maneuvers because they're flying in air and can use the force of drag or airfoils to change direction. When you're flying in space there is no dragging force because there's no air.

The only reason that I did this exercise is to show that what these spaceships do in the movies is strictly fantasy. No one has the technology to accomplish these amazingly rapid changes in direction. Although, since they're in a galaxy far, far away . . .

Thanks for reading.