On Tuesday, July 21, 2020, two NASA astronauts will perform the second in a pair of International Space Station (ISS) spacewalks, to finish a 3 1/2-year effort to upgrade the station’s power system. At completion, 24 new lithium-ion batteries and adapter plates will replace 48 aging nickel-hydrogen batteries. NASA TV’s live coverage of the spacewalk will begin on Tuesday at 10:00 UTC (6:00 a.m. EDT). The spacewalk itself will begin at around 11:35 UTC (7:35 a.m. EDT), and will last as long as 7 hours. Translate UTC to your time. The first of the spacewalks happened on Thursday, July 16. Watch here.
On Tuesday’s spacewalk NASA astronauts Chris Cassidy and Robert Behnken will remove two lifting fixtures used for ground processing of the station’s solar arrays prior to their launch. They’ll also begin preparing the Tranquility module for the installation of a commercial airlock scheduled to arrive on a SpaceX cargo flight later this year. The airlock will be used to deploy commercial and government-sponsored experiments into space.
Behnken will be designated extravehicular crewmember 1 for the spacewalk. Look for him in a spacesuit with red stripes. Cassidy will be extravehicular crewmember 2, wearing a suit with no stripes.
— Chris Cassidy (@Astro_SEAL) July 17, 2020
On the July 16 spacewalk, the astronauts removed six aging nickel-hydrogen batteries for the second of two power channels for the starboard 6 (S6) truss, installed three new lithium-ion batteries, and installed the three associated adapter plates that are used to complete the power circuit to the new batteries. Mission Control reports that all three new batteries are working.
In all, 12 spacewalks will have been performed since January 2017 to change out batteries for eight power channels used to route electricity on the station.
Bottom line: Watch two ISS astronauts spacewalk on July 21, 2020.