When NASA astronauts Mike Hopkins and Victor Glover made a spacewalk on February 1, they packed up a multi-year effort to replace the old nickel-hydrogen batteries on the ISS with new lithium-ion models. The International Space Station program approved the development of lithium-ion batteries to replace the station’s aging energy storage system in 2011. Battery production began in 2014, and the first lithium-ion replacements have started. flew to the station aboard JAXA. Kounotori 6 supply flight in December 2016. Now, four years after that flight and 14 spacewalks with 13 different astronauts later, the upgrade is finally complete.
Ground controllers used the Canadarm2 robotic arm to position some of the batteries for installation. However, some required additional spacewalks for places the arm couldn’t reach. Batteries aren’t quite like the lithium-ion we’re used to, with their space-grade lithium-ion cells and radiant protective shield. As lithium-ion technology has a higher energy density than nickel-hydrogen, only 24 new batteries were needed to replace the old 48.