If I'm in one of those carnival rides that spin fast I can feel the centrifugal force. This is due to the radial acceleration caused by the centripetal force, the constraining force of the carnival ride mechanism. But if I'm in Earth orbit in a space shuttle, I feel no such centrifugal force. I understand how GR explains the lack of any centrifugal force while one is falling around the Earth. But how does classical (Newtonian) mechanics explain the lack of any centrifugal force while in orbit? As always, thanks in advance.