On May 16, 2018, American astronauts Andrew Feustel and Richard Arnold performed a spacewalk to reposition two spare solar array ammonia coolant pump assemblies, putting a failed unit, dubbed “Leaky,” into long-term storage and attaching another, known as “Frosty,” to an appendage of the lab’s robot arm. The EVA (extravehicular activity) lasted 6 hours and 31 minutes. This was the eighth spacewalk for Andrew Feustel and the fourth for Richard Arnold.