During today's spacewalk, @Astro_Christina & @Astro_Jessica move a battery on the @Space_Station's port truss as they work on an upgrade of station power systems. The batteries store power collected from the solar arrays. Watch & ask questions w/#AskNASA: https://t.co/CEsJrxByMF pic.twitter.com/lEXm5JRrxc

— NASA (@NASA) January 15, 2020