ISS SPACEWALK TO REPLACE BATTERIES, July 21, 2020, Earth orbit, 7:35 am ET

NASA astronauts Chris Cassidy and Bob Behnken will make a fourth spacewalk to replace batteries on the outside of the International Space Station on July 21, 2020.

NASA TV coverage begins at 6:00 am ET.  The spacewalk will begin at 7:35 am ET and last as many as 7 hours.