Answer to Question #149530 in Mechanics | Relativity for Mikkos Joshua Garcia

Question

How can a rocket change direction when it is far out in space and essentially in a vacuum?

Answer 1

When a rocket expels gas in a given direction, it puts a force on that gas. The momentum of the gas rocket system stays constant, and so if the gas is pushed to the left, the rocket will be pushed to the right due to Newton's 3rd law. So the rocket must carry some kind of material to be ejected (usually exhaust from some kind of engine) to change direction.