Robot Swaps Faulty Breaker At Station

The two-armed Canadian robot Dextre replaced a faulty circuit breaker outside the International Space Station late Monday, obviating the need to send astronauts out on an inherently dangerous spacewalk to perform the same work.

Dextre opened a cargo container box attached to a spare parts pallet on the port side of the station's central truss. The robot used the hand on one arm to snare a spare circuit breaker and removed it from the box.

The hand on Dextre's other arm was used to grasp the faulty circuit box and remove it from its housing on the first port-side section of the segmented truss.

The new spare was put in place, and then Dextre stored the faulty circuit breaker in the container box.

Ground controllers put Dextre through its paces over a two-day period. The work was completed while the six astronauts and cosmonauts onboard the station slept.

Dextre was delivered to the station in March 2008 by astronauts flying aboard the now-retired shuttle Endeavour. The robotic handyman is a key part of a Canadian-built system that includes the station's 57.5-foot robot arm, a mobile transporter, and a rail system that runs across the station's 356-foot central truss.

The mobile transporter can move Dextre and the station's construction crane-like arm to work sites along the truss.

Dextre's first big job was completed in February. It unpacked two pieces of equipment from a robotic Japanese space freighter that delivered tons of cargo to the orbiting outpost.