Question

Why moon cannot be used as a communication satellite?

Answer 1

The Moon has several problems that make it insuitable for communications purposes at this time:
- It is very far away, so a signal would take about 2.7 seconds to make the round trip to the Moon and back, many communications require much shorter delays than this.
- It is very far away, so signals would tend to dissipate a lot going in both directions and would be relatively weak once they reached their destination and require a proportionally more powerful receiver or transmitter.
- It is very far away, so it would be difficult to put a relay station there and difficult to maintain any relay station after it was in place.
- There is only one of them, so only about half of the Earth's surface has a line of sight to it at any one time.
For these reasons, artificial satellites orbiting the Earth are considerably more effective for communications than a relay station on the Moon would be.