Video narration
How can a Moon rover get a message all the way to Earth? Think of sending a phone message through a network relay. The information is handed from one station to the next, instead of making one giant leap. The rover begins by sending a radio signal. It can carry rover data, or commands for the rover, across space. Here's the key: the rover does not need to reach Earth directly. A relay satellite catches the signal and forwards it. The satellite is a middle link, not the destination. It receives the message, then sends it onward toward Earth. At an Earth ground station, the radio signal is received and passed into Earth's communication network. So how does the message make the journey? From the Moon rover, to the relay satellite, to the ground station on Earth. The satellite is the handoff that makes the path possible.