Recently, astronauts aboard the International Space Station carried out a standard “walk-off” operation using the massive robotic arm that stretches some 58 feet long and is attached to the orbiting laboratory. Known as Canadarm2, the arm was provided by the Canadian Space Agency. It moves along the exterior of the station in a manner similar to an inchworm, with both ends being nearly identical.
Engineers detected problems with the arm and the mobile transporter that carries it along the main truss of the space station following this specific walk-off maneuver.
By Sunday night, per two separate reports, investigators were still weighing whether the malfunction stemmed from a data or software glitch or from some mechanical failure within the robotic arm or the mobile transporter hardware. (Update: NASA issued a statement at 2 pm ET on Monday.)
The Walk-Off Maneuver
While moving the station’s robotic arm, which was fitted with Canadarm2, crew members noticed problems with both the arm itself and the mobile transporter that moves it along the main truss. The maneuver was a standard “walk-off”, and the trouble appeared during its course.
By Sunday night, two sources confirmed that engineers were still attempting to determine whether the issue originated with software or hardware. The transporter’s non-robotic components had exhibited some communication errors, while the arm itself remained operational.
What NASA Says Now
On Monday, NASA released a statement at 2 p.m. ET confirming that Canadarm2 is functioning normally and is now being used to inspect the Crew-12 Dragon spacecraft as part of the predeparture process. The agency’s update includes the fact that the robotic arm is being used for inspection purposes.
The statement adds that certain non-robotic parts tied to the mobile transporter have shown communication problems. NASA is working through and looking into those issues ahead of the transporter’s move away from its present worksite, which goes by the name Worksite 6.
In parallel, NASA and SpaceX are working to ensure there is no GPS interference affecting Dragon’s docking capability to the station’s forward port. Joint teams are actively conducting the analysis and expect to resolve the issue before the Crew-13 launch.
NASA will offer more information at the Crew-13 prelaunch news conference on Wednesday, Sept. 30, with further details to be provided at that time.
The Arm’s Long History
MDA, a Canadian space corporation, built Canadarm2. The robotic arm reached the International Space Station in April 2001, arriving on Space Shuttle Endeavour.
The planned operational span was 15 years, yet the system has kept running well past that mark, now exceeding its original target by more than a decade.
What Stays Up in the Air
The arm is currently operating as expected. It is examining the Crew-12 Dragon spacecraft while the station holds back until the transporter problem gets resolved.
The circumstances serve as a reminder that even machines designed to endure for decades will eventually encounter unforeseen difficulties.
The Fix Timeline
| Event | Timing |
|---|---|
| Walk-off maneuver | Recent |
| Initial diagnosis | Sunday evening |
| NASA statement | 2 p.m. ET Monday |
| Crew-13 prelaunch conference | Wednesday, Sept. 30 |
Key Numbers
- Arm length: 58 feet
- Launch: April 2001, Space Shuttle Endeavour
- Design lifetime: 15 years
- Current age: More than 15 years
- Next step: Resolve transporter communication errors before Crew-13 launch
It remains to be seen if the repair lasts through the coming days. The arm is performing its function, which is all anyone can currently claim.
Source material: “NASA, for the time being, is unable to move the space station's large robotic arm,” Ars Technica.
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