What is a Satellite? The History and Technology Explained
Every usable artificial satellite whether it’s a human or robotic one — has four main parts to it: a power system (which could be solar or nuclear, for example), a way to control its attitude, an antenna to transmit and receive information, and a payload to collect information (such as a camera or particle detector).
As will be seen below, however, not all artificial satellites are necessarily workable ones. Even a screw or a bit of paint is considered an “artificial” satellite, even though these are missing these parts.
Source: What is a Satellite? – The History and Technology Explained | Space