Here's why:

* Gamma rays are extremely high-energy radiation. They are harmful to living organisms and would not be suitable for transmitting data.

* Satellites typically communicate using radio waves. Radio waves are a type of electromagnetic radiation with much lower energy than gamma rays. They are safe to use and can travel long distances through the atmosphere.

Here's a breakdown of common satellite communication methods:

* Uplink: Ground stations transmit signals to satellites using radio waves in specific frequency bands.

* Downlink: Satellites receive signals from ground stations and transmit data back using radio waves.

In short, gamma rays are not used for satellite communication due to their high energy and potential harm.