I was just thinking this conversation is clear who has played KSP.

Simplified, you have a rocket orbiting around the earth going over both poles in a circular orbit. Above the north pole its 250km high and fires off its rocket all at once. Now its orbit is an eclipse going to 500km above the south pole, but it will return to 250km above the north pole. If you want to increase your altitude over the north pole you would need to accelerate above the south pole.

Orbiting is much more about going really really fast than it is about going really high up. Vast majority of the acceleration of launching into orbit goes into acceleration parallel to the ground rather than lifting away from it.