The Sahara Desert visible through the windows of the cupola on the Tranquility module. - stock photo

The tan, brown, and orange Sahara Desert is visible through the windows of the cupola on the Tranquility module. Tranquility holds some of the station�s environmental control equipment, such as the system that cleans carbon dioxide from the air, and it also provides living space for exercise equipment and a bathroom. Tranquility also comes with a cupola, a dome-shaped viewing port made up of seven windows.