The flight will last thirteen days and includes three spacewalks to replace experiments outside the European Space Agency's Columbus laboratory, install a new ammonia storage tank and return the used one. Ammonia is needed to move excess heat from inside the station to the radiators located outside.
The mission marks the start of the transition from assembling the space station to using it for continuous scientific research.
Assembly and maintenance activities have dominated the available time for crew work. As completion nears, additional facilities and the crew members to operate them will enable a measured increase in time devoted to research as a national and multinational orbiting laboratory.
Discovery's first landing opportunity at Kennedy is scheduled for Thursday, Sept. 10th. This mission is the 37th mission for Discovery, and the fourth this year.