Two astronauts will venture outside the International Space Station today (March 22) to replace old batteries on the station's solar arrays. This will be the first of three spacewalks scheduled to take place over the next three weeks, and you can watch them all live online!
Today, NASA astronauts Anne McClain and Nick Hague — both first-time spacewalkers — will begin the spacewalk trifecta with a planned 6.5-hour excursion outside the orbiting laboratory. They will exit the Quest airlock at 8:05 a.m. EDT (1200 GMT), and you can watch it live here on Space.com. NASA's webcast will begin at 6:30 a.m. EDT (1030 GMT).
One week from now, McClain will head out for her second spacewalk together with NASA astronaut Christina Koch. That will be the first all-female spacewalk in history. During these first two spacewalks, astronauts will continue ongoing work to upgrade the space station's power system by replacing old nickel-hydrogen batteries with new and improved lithium-ion batteries. These upgrades began in 2017, when NASA astronauts Shane Kimbrough and Peggy Whitson and European Space Agency astronaut Thomas Pesquet swapped out the first set of batteries in a pair of back-to-back spacewalks.
Twelve of the old nickel-hydrogen batteries will be replaced with six larger lithium-ion batteries, each about the size of a miniature refrigerator. Located in the power channels for the space station's solar arrays, these batteries store power generated by the solar panels and help to power the station when it's orbiting on the dark, nighttime side of Earth. Much like the battery in your cellphone, aging batteries on the space station start to hold less charge.
The current set of batteries has been at the station for nearly 12 years, and the new batteries are expected to last until the end of the space station's lifetime, Kenneth Todd, NASA's space station program manager, said during a briefing on Tuesday (March 19). NASA is currently planning on ending its space station operations in 2024, although members of Congress are fighting to have it extended to 2030. "The new lithium batteries are certified for 10 years, but expected to last around 20 years," NASA spokesperson Kelly Humphries told Space.com in an email.
On April 8, the third and final spacewalk in this series will feature an all-male spacewalking team working on something entirely different. Canadian Space Agency astronaut David Saint-Jacques, also a first-time spacewalker, will join Hague on a mission to route a redundant power supply to Canadarm2, a 58-foot (18 meters) robotic arm used to grapple visiting spacecraft. To do this, the astronauts will lay out a set of jumper cables in between the Unity module and the Starboard-0 (S0) truss, a segment located "at the midpoint of the station’s backbone," NASA officials said in a statement.
- FAQ: How Do Astronauts Take Spacewalks?
- How NASA Spacesuits Work: EMUs Explained (Infographic)
- Gallery: The Most Memorable Spacewalks in History