Tranquility, also known as Node 3, is a module of the International Space Station (ISS). It contains environmental control systems, life support systems, a toilet, exercise equipment, and an observation cupola.

The International Space Station (ISS) is a large space station assembled and maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA, Roscosmos (Russia), JAXA (Japan), ESA (Europe), and CSA (Canada). The ISS is the largest space station ever built. Its primary purpose is to perform microgravity and space environment experiments.