The large robotic arm on the International Space Station has stopped working

A routine "walk-off" maneuver left Canadarm2 and its mobile transporter immobile, and engineers are investigating whether the fault is in software, data, or the hardware itself. The 58-foot Canadarm2, supplied by the Canadian Space Agency and built by MDA, launched in April 2001 and is operating well beyond its 15-year design life. The arm weighs nearly two metric tons and can handle up to about 116 tons. NASA declined to comment publicly as technicians and flight controllers worked to diagnose and restore movement after the arm failed to reposition along the station truss.

Loss of arm functionality would complicate key station operations because the manipulator has been central to berthing visiting cargo vehicles and moving large external hardware for spacewalk preparations. Modern Dragon and Starliner vehicles can dock autonomously, but Northrop’s Cygnus and Japan’s HTV-X still rely on capture by the arm, so cargo logistics would become more difficult if the arm remains unusable. The failure underscores risks from long-term aging of the nearly 30-year-old facility and highlights the unsettled transition to commercially developed replacement stations that are meant to succeed the current outpost.