Dextre, the giant robot being assembled on the International Space Station, has regained its power.
The glitch that left the robot unresponsive was not an issue with the robot itself, but with a faulty cable that should have been feeding it electricity and computer commands.
After several days of engineers from NASA and the Canadian Space Agency grappling to find an answer to why the US$2 million, 12-foot-tall robot wouldn't power up or respond to computer commands, their troubleshooting paid off late Friday night.
Bypassing what engineers had suspected was a faulty cable, the space station crew grab hold of Dextre - pronounced Dexter - with Canadarm 2, which is a large robotic arm that has been on the space station for the past seven years. NASA reported on its Web site Saturday that they grappled the Canadian-built Dextre 9:59 p.m. EDT on Friday. Canadarm2 successfully powered up Dextre 11 minutes later.
Being able to power up the robot, which was carried aloft on board the space shuttle Endeavour, was critical, explained Michel Wander, a systems engineer who worked on Dextre at the Canadian Space Agency.
"The problem with not being able to power up the robot -- other than having an unresponsive 3,400-lb., US$2 million robot attached to the space station -- is that Dextre eventually will need to receive enough electricity to keeps its joints, cameras and sensors from freezing up in the harsh conditions of space," he said. Wander had said in an earlier interview that astronauts already had the robot covered with thermal blankets but in about a week, those blankets wouldn't be enough to protect the robot from the brutal cold.
The engineers at NASA and the Canadian Space Agency first suspected that the problem was a bug in the software. Canadian programmers immediately began building a patch that was sent to the space station via radio dishes. The software patch didn't fix the problem.
Wander said after that, the engineers suspected that the issue lay in a configuration problem with the cable that links Dextre to the pallet that the robot is attached to. Electricity and software commands should be going to Dextre through the cable.
Dextre was designed to handle maintenance jobs outside the space station, relieving astronauts from having to perform as many dangerous space walks.
Later this weekend, astronauts are slated to attach Dextre's arms to its body. It's grippers, or hands, were attached to the arms earlier this week. People can watch the astronauts assembling the robot on NASA TV.