In which atmospheric layer do space shuttles typically orbit?

Space shuttles typically orbit within the thermosphere, which extends from about 80 kilometers (50 miles) above sea level to 600 kilometers (373 miles) or more. This atmospheric layer is characterized by a significant increase in temperature with altitude, primarily due to the absorption of high-energy solar radiation.

In the thermosphere, the density of air is very low, allowing for spacecraft to maintain their orbits with lesser air resistance. Moreover, the thermosphere contains the ionosphere, a region filled with electrically charged particles, which is crucial for radio communication and GPS systems used by shuttles. Thus, the thermosphere is the ideal layer for space shuttles to operate as it provides the necessary conditions for stable and efficient orbiting.

Other layers mentioned, such as the mesosphere, are located below the thermosphere and do not provide the necessary conditions for spacecraft to achieve orbit. The hydrosphere pertains to water bodies and is not a layer of the atmosphere, while the exosphere, although also an outer layer of the atmosphere, is higher and has even lower particle density, making it less practical for space shuttles to orbit effectively.