It seems the Canadarm2 on the International Space Station is in need of hands-on maintenance after developing an issue that has limited its operations.
On May 27, the station’s iconic robotic arm suffered a mechanical hiccup during routine operations when a wrist joint experienced an unexpected spike in motor current and stopped moving normally.
With the robotic arm pausing its non-essential duties, NASA and the Canadian Space Agency (CSA) quickly agreed to a solution: a spacewalk.
Canadarm2 was built to be serviced, though the mechanics in this case will be a couple of the ISS’s astronauts. The robotic arm is highly modular, meaning its segments can be pulled out and swapped in the vacuum of space. Because wear and tear is expected for a machine operating ten years beyond its original design life—it recently passed 25 years of service—the CSA already has a spare joint stowed aboard the station.
This won’t be the first time Canadarm2 has needed some orbital work or taken a hit. During a series of spacewalks in late 2017 and early 2018, astronauts successfully replaced both of the robotic arm’s Latching End Effectors (LEEs)—the intricate “hands” at either end of the arm that grapple cargo—after they showed signs of mechanical fatigue.
More recently, during a routine inspection in May 2021, the CSA and NASA discovered the arm had taken a direct hit from a piece of orbital micro-debris. The debris punched a small hole through a thermal blanket and a boom segment, but because the strike missed critical components, the arm continued to function flawlessly without needing repairs.
Now, facing this new mechanical issue, mission controllers and the Expedition 74 crew are gearing up for a spacewalk on June 30 to replace the faulty joint, ensuring the station’s robotic workhorse can get back to catching cargo ships.
What happens next
Active Spacewalk Prep: As of June 15, the Expedition 74 crew is deep into spacewalk preparations. NASA astronauts Chris Williams and Jessica Meir have been inside the Quest airlock configuring tools, adjusting spacesuit limbs, and verifying valve and switch configurations for the upcoming excursion.
The June 30 Target: The spacewalk to replace the joint remains officially targeted for Tuesday, June 30 — notably just one day before Canada Day.
Cargo Logistics: While prepping for the repair, the crew has also been busy packing up a SpaceX Dragon cargo spacecraft with temperature-controlled scientific samples so it can return to Earth today, clearing the deck for the repair work ahead.
NASA is expected to host a dedicated news conference in the coming days to discuss the spacewalk.