NASA's Anne McClain and Nick Hague took 6 hours and 39 minutes to replace three old nickel-hydrogen batteries with more powerful lithium-ion batteries on the International Space Station. There are more replacements of the 20-year-old station's original batteries to come. NASA is about halfway through replacing 48 batteries with ones that are expected to last the remainder of the station's life. The space station uses solar panels to generate power but the batteries are used when it's in the dark and not getting power from the sun. This was the 214th spacewalk to assemble and maintain the space station.

Source: ABC News March 22, 2019 12:20 UTC