The Cupola is an ESA-built observatory module of the International Space Station (ISS). Its seven windows are used to conduct experiments, dockings and observations of Earth. It was launched aboard Space Shuttle mission STS-130 on 8 February 2010 and attached to the Tranquility (Node 3) module. With the Cupola attached, ISS assembly reached 85 percent completeness. The Cupola is the largest window ever used in space.