Astronauts Anne McClain and David Saint-Jacques embarked on a spacewalk Friday, April 8, to continue work on the International Space Station (ISS). This marks the third spacewalk of 2019, adding to the successful March 22 and March 29 journeys outside the space station.

The latest spacewalk established a “redundant path of power” to the Canadian-built Canadarm2 robotic arm, and installed “cables to provide for more expansive wireless communications coverage outside the orbital complex, as well as for enhanced hardwired computer network capability,” according to NASA.

To prepare for more ISS battery upgrades in the future, McClain and Saint-Jacques also repositioned an adapter plate established in the March 22 spacewalk. 

Among other tasks, last month’s spacewalks replaced the station’s nickel-hydrogen batteries with a set of more powerful lithium-ion batteries.

Throughout each of 2019’s ventures outside the space station, the public was able to watch the action live through a NASA TV stream, as well as submit questions to the NASA commentators. One such question was, “How do you get power on the station?”

According to the commentator, the space station is powered completely by the sun, as evident in its staple solar arrays. The solar arrays capture the sun’s light, and stores that power in the space station’s batteries. And the whole system gets help from a component known as the battery charge/discharge unit. “When the station is in the sunlight, it stores the power, and when in darkness, it discharges through the batteries, which then powers the space station,” according to NASA TV.

The next spacewalk this year is schedule for May 29, featuring Russian cosmonauts Alexi Ovchinin and Oleg Kononenko.