Here's why:

* Exosphere: The outermost layer, where the atmosphere gradually fades into space. It's too thin for satellites to orbit.

* Thermosphere: Characterized by very high temperatures due to solar radiation. While it's incredibly thin, it's dense enough for satellites to use atmospheric drag for orbital maneuvering.

* Mesosphere: This layer burns up most meteors and has strong winds. It's too dense for stable orbits.

* Stratosphere: Contains the ozone layer, which absorbs harmful UV radiation. It's too dense for stable orbits.

* Troposphere: The lowest layer, where weather occurs. It's too dense for satellites to orbit.

Important Note: The specific altitude within the thermosphere varies depending on the type of orbit, the spacecraft's purpose, and other factors.