KSC-07pd2018

KENNEDY SPACE CENTER, Fla. -- In the Orbiter Processing Facility bay 3, STS-120 crew members get a look at the main bus switching unit that is part of the payload on their mission. From left are Mission Specialists Scott Parazynski and Doug Wheelock at left and Mission Specialist Paolo Nespoli at right. Nespoli represents the European Space Agency. A main bus switching unit is used for power distribution, circuit protection and fault isolation on the space station's power system. The units route power to proper locations in the space station, such as from solar arrays through umbilicals into the U.S. Lab. The unit will be installed on the external stowage platform 2 attached to the Quest airlock for temporary storage. Discovery is targeted to launch mission STS-120 no earlier than Oct. 20. Photo credit: NASA/Jim Grossmann