Among their tasks, the astronauts successfully connected two ammonia loops to Tranquility, to install the module´s cooling system, according to NASA´s website.

Tranquility was made in Italy.

It is named after the site where U.S. astronauts first landed on the moon in 1969.

It will act as a second habitation module for the live-aboard station crew.

Tranquility will house a toilet, oxygen generator, air scrubber and water recycling system.

Four more shuttle missions remain to finish outfitting the station before NASA retires its three-ship fleet at the end of the year.