Why do rockets launch in an arc, and not just go straight up?

Question

Why do rockets launch in an arc, and not just go straight up?

In: 4

Answer 1

Space is up, orbit is sideways.

You need to go up so you get out of the atmosphere which slows you down. But more importantly, you need to pick up a lot of sideways speed so you stay in orbit instead of hitting the ground again.

Starting with the “up” portion is more efficient since you want to leave behind the pesky air as soon as possible. That gives you the arc. On a mountainless, airless planet, you could have the launch pad horizontally.