Two astronauts will venture outside the International Space Station on Friday (Jan. 6) to perform a complex upgrade to the outpost's power system.
The extravehicular activity (EVA) is scheduled to begin at 6 a.m. CST (1200 GMT).
Working on the right side of the space station's truss, Expedition 50 commander Shane Kimbrough and flight engineer Peggy Whitson will install adapter plates and hook up electrical connections for six new lithium-ion batteries that were delivered to the station in December.
The new batteries are replacing 12 older nickel-hydrogen batteries. Nine of the older batteries will be stowed in a cargo resupply craft for later disposal, while three will remain on the truss, disconnected from the power grid.
This is the 196th spacewalk in support of space station assembly and maintenance. Kimbrough is designated EV1, wearing the suit bearing red stripes. It is the third spacewalk of his career.
Whitson is making her seventh EVA, matching Suni Williams' record for the most spacewalks by a woman. She is wearing a spacesuit with no stripes.
The work will continue Jan. 13 during a second spacewalk, which will be conducted by Kimbrough and flight engineer Thomas Pesquet of the European Space Agency (ESA).