The speed of an object in orbit is necessary to overcome the rate at which it is falling due to Earth's gravitational pull.
By obtaining an orbit no more energy is required to keep something in space.
Not all objects travel at great speeds.
It really depends on a couple of things initial velocity, which would stay relatively constant due to the lack of friction in space. Changes in momentum caused by collisions and Gravitational pull due to the attractions of others masses in space.
The shuttle turns as it leaves the Earths atmosphere so that it can take up an orbit around the Earth