The ISS module added in 2010 that provided additional living space and life support for the US segment was Tranquility. It is also known as Node 3.
Tranquility was launched aboard Space Shuttle Endeavour on February 8, 2010, during mission STS-130, and berthed with the Unity node four days later. The module was manufactured in Italy by Thales Alenia Space through a partnership involving the European Space Agency and the Italian Space Agency, then transferred to NASA under an ISS barter agreement.
Its environmental-control and life-support systems recycle wastewater, generate oxygen, and help remove contaminants from the station’s atmosphere. Tranquility also houses a toilet, exercise equipment, storage, and connections for other station hardware. The Cupola observation module is attached to one of its berthing ports.
The main mix-up is with Harmony, another US-segment node delivered earlier, in 2007. Destiny is the US laboratory, while Unity is the station’s first connecting node. Tranquility’s role is broader: it combines habitation support, life-support machinery, exercise facilities, and access to Cupola.