Chris Williams and Jessica Meir fix Canadarm2’s wrist in 7h 20m, just for Canada Day

On June 30, 2026, NASA flight engineers Chris Williams and Jessica Meir climbed out of the Quest airlock and spent 7 hours and 20 minutes repairing the International Space Station’s Canadarm2 robot arm, swapping out a faulty wrist joint after the arm was observed drawing current but not moving as expected in late May.

That “current but no motion” clue mattered. It signaled an issue in the remote manipulator system (RMS) that could degrade the arm’s ability to do its job, from maintenance support to moving payloads and catching visiting cargo vehicles. Canadarm2, the 58-foot-long (18 meters) robotic arm installed on the orbiting lab in April 2001, has been in regular use ever since, and on Tuesday the crew treated the problem like a true operational risk: diagnose quickly, bring the right spare, and get the arm back to a state where Mission Control can confirm it is powered correctly and performing as expected. When Williams later said the timing felt meaningful, it was not just celebration. “For over 25 years,” the Canadarm2 has been a crucial part of the ISS, he said, and the work was aimed at ensuring the arm can keep playing that “workhorse” role.

The repair sequence itself reads like the ISS version of “stop the bleeding, then fix the system.” After switching their spacesuits to battery power at 8:20 a.m. EDT (1220 GMT), Williams and Meir ventured outside soon after. They first transitioned to their work station and retrieved a spare wrist joint by using a power tool, described as a pistol grip unit, to unbolt the existing joint from an exterior equipment panel. With the old unit removed, they installed the replacement wrist joint, identified as “no. 5,” and bolted it in place. That “numbered joint” detail matters in space hardware because spares are tracked like inventory with lineage. The wrong part, the wrong orientation, or a loose connection is not a minor slip. In orbit, it can mean days of delay, wasted EVA time, or a degraded operational window.

Once the new joint was secured, the astronauts completed the work by reattaching Canadarm2’s latching end effector, or “hand,” the component the arm uses to grapple objects and inchworm across the exterior of the station. Mission Control then confirmed good power connections after the astronauts’ work, which is the operational green light the program needed. The faulty joint did not just get thrown back into the black. Williams and Meir brought it into the station to be returned to Earth for analysis and possible refurbishment. That closed-loop approach is what turns one EVA into institutional learning: diagnose in orbit, replace for continuity, then study what failed on the ground to improve future maintenance planning and spare strategy.

This EVA was also not a one-off. Tuesday’s spacewalk marked the fourth time in history that spacewalkers have serviced Canadarm2. Previously, another wrist joint was replaced and both of the arm’s end effectors were swapped out for spares. Williams has now logged 14 hours and 22 minutes across two spacewalks, including the previous EVA with Meir. Meir totaled 36 hours and 6 minutes, including the first all-female EVA in 2019. That experience matters because space robotics operations sit at the intersection of human procedure and machine performance. When the RMS can’t move, it is not only an equipment issue. It can ripple into payload handling, maintenance cadence, and the safety margins for spacewalk support.

There is also a politics-and-partnership layer here, and it is not just ceremonial. Williams described Canadarm2 as a testament to international cooperation, saying “Canada, the U.S. and the world have come together to make this program a success.” The ISS is a multinational architecture, and on Tuesday the team effort extended beyond the two astronauts doing the physical work. Expedition 74 flight engineers Jack Hathaway of NASA and Sophie Adenot of the European Space Agency assisted by helping Williams and Meir don and doff their spacesuits and maneuvering Canadarm2 into position for the repair. In other words, the EVA was the visible layer, but the operational capability required coordination across agencies, roles, and time zones.

Even the end time tells you it was a planned execution, not an improvised scramble. Williams and Meir returned to the Quest airlock and began depressurization at 3:40 p.m. EDT (1940 GMT), completing the EVA. And while Meir said they repaired the “mighty Canadarm2 just in time for Canada Day tomorrow,” that line lands because Canadarm2 is not a decorative feature. It has been an operational backbone since April 2001, and protecting that backbone is how ISS maintains momentum for assembly, maintenance, and upgrades. Tuesday’s EVA was the 280th in support of ISS assembly, maintenance, and upgrades since 1998, a reminder that this kind of work is continuous. For leaders overseeing complex systems on Earth or in orbit, the lesson is clear: you do not wait for catastrophic failure. You build schedules, spares, and procedures that let you fix critical components before the capability meaningfully degrades.