Why does a rocket need to reach escape velocity to get to outer space?
It doesn’t. The escape velocity that people talk about with regard to getting into space is a misnomer. It is actually the minimum speed which an object launched from the surface would have to be travelling at to never fall back. It is not actually necessary to ever attain this speed in a powered vehicle such as a rocket. Think of the rocket halfway through it’s powered climb. At this point it is a considerable distance above the ground so the ‘escape velocity’ from here is less than the escape velocity from the surface. The rocket is also still accelerating so it doesn’t even need to be going at escape velocity yet and it can still get into space. In fact the rocket only needs to reach escape velocity a moment before the engines stop. So long as the rocket is at escape velocity for where it is when the engines stop it will carry on going. This point is of course a greater distance away from the earth and so has a lower escape velocity than that at the surface of the earth. With regard
