The arm, which passed 25 years of service in April, demonstrated an elevated motor current in a wrist joint, and arm motion did not occur as expected, NASA officials wrote in a blog post on June 10. Consultation with the Canadian Space Agency, which funds the arm and supports its operations with MDA Space, confirmed that a spacewalk would be needed. A spare joint is already aboard the station.
The arm is in a stable position while awaiting the repair. The CSA noted that Canadarm2 was designed for this kind of maintenance. It is made up of several segments that can be pulled out and replaced in space, the agency wrote, adding that key spares were shipped to the station well in advance. A similar repair occurred in 2017 with one of the arm’s robotic hands after it began to show signs of normal wear.
NASA plans a news conference at a date to be announced to discuss the spacewalk and identify the assigned astronauts. The two spacewalkers will likely come from the Expedition 74 crew on the U.S. side of the station, which includes NASA’s Chris Williams, Jessica Meir and Jack Hathaway, and the European Space Agency’s Sophie Adenot. The last Canadarm2 berthing took place in April, with Williams controlling the arm and Hathaway supporting to capture the arriving Northrop Grumman Cygnus XL spacecraft. SpaceX Dragon CRS-34 is scheduled to depart the station on June 16.
Canadarm2 was not originally designed for spacecraft arrivals. It flew to the station in 2001, before the rise of commercial spacecraft, yet made its 50th cosmic catch in 2024 and continues to operate despite being 10 years past its design life this year. Over the decades, more tasks have shifted to ground controllers in Houston and at CSA headquarters near Montreal. Controllers in Canada alone support more than 100 days of Canadian ISS robotics work each year, including the Dextre robotic hand, picking up equipment, transferring experiments, and performing other duties that do not require astronaut time.
Getting the arm back online is critical to berth some cargo ships carrying food, equipment and supplies, and to perform a share of station maintenance. The CSA’s robotics represent its share of the ISS funding arrangement, allowing Canadian astronauts and science to fly. The next CSA astronaut to reach the station will be Josh Kutryk, flying aboard SpaceX Crew-13 no earlier than September. The last was David Saint-Jacques in 2018 and 2019.
Canadarm2 is part of a long line of Canadian space robotic arms. The first Canadarm debuted on the second space shuttle mission in 1981. Canadarm3 is now being built to support the Artemis program, which saw CSA astronaut Jeremy Hansen fly around the moon on Artemis 2 in April.
NASA will announce the spacewalk date and the assigned crew at an upcoming news conference. The repair is set for no earlier than June 30, leaving the station without its primary robotic arm for at least another two weeks.
