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, a second habitation module for the live-aboard station crew, 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.