A satellite is intended to remain fixed over a particular point on Earth’s surface.
(i) State the two essential orbital conditions that must be satisfied for such a satellite to appear stationary to an observer on Earth.
(ii) Explain clearly why the orbit of this satellite must lie in Earth’s equatorial plane and why its motion must be in the same sense as Earth’s rotation.
(iii) Distinguish between a satellite placed in this orbit and one placed in a polar circular orbit with respect to (a) period, (b) ground track, and (c) typical applications.