The direction of rotation of Earth is from west to east. Therefore the rockets are also launched in this direction so that they may take the place of geostationary satellite. The rockets are launched on equator surface because they may be geo-station only in this plane. The reason of launching the rockets from west to east is to minimise the consumption of fuel because by this action, the relative velocity of the rocket = velocity of rocket + velocity of earth.
Thus, the velocity of rocket increases resulting the less consumption of fuel.
