The space station's robotic arm (left) attaches to a power data grapple fixture of the the Dextre robot (right), which is secured in a high-tech shipping pallet.
Credit: NASA TV
This story was updated at 2:53 a.m. ET.
HOUSTON — Astronauts remedied a power glitch with a giant robot outside the International Space Station (ISS) Friday evening, poising spacewalkers to attach its two arms tonight.
NASA and Canadian mission managers said Friday morning that a flawed cable in a pallet containing the pieces of the 1.7-ton robot, named Dextre, was to blame. To prove the hypothesis, astronauts grappled Dextre's "head" with the space station's robotic arm around 9:59 p.m. EDT (0159 GMT March 15) — a power-providing move that circumvented the flawed wiring.
"I guess I have to say it: It?s alive!" Pierre John, acting program manager for the Canadian space station program, said here at Johnson Space Center after Dextre's successful power-up. "This morning ? I was cautiously optimistic," he said, "but the proof is in the pudding."
Jean explained that the electricity now feeding heaters should keep the robot's vital electronics from being damaged by the harsh cold of space.
Dextre is a servicing robot designed to cut back on the number of dangerous spacewalks astronauts will perform outside of the space station. Led by commander Dominic Gorie, the STS-123 shuttle Endeavour mission delivered Dextre's pallet to the ISS on Wednesday and Japan's first orbital room on Friday morning.
Shortly after the platform's attachment, however, mission controllers found that their commands to route power to the robot failed, as did a Friday afternoon software patch aimed to solve the problem.
Jean said the problem can ultimately be traced back to a mistake made when engineers were asked to change the way Dextre's pallet was powered by the space station. He explained that the cable was not broken — it just wasn't the correct kind for the powering system, preventing the space station's computers from communicating with the high-tech robotic pallet.
"The cable design wasn't updated for the system," Jean said of the oversight that blocked the flow of electricity. "It was one of those things that sometimes happens. I don't think you can really lay blame ? on anyone."
Spacewalkers Rick Linnehan and Garrett Reisman, an ISS flight engineer, attached the robot's hands during a seven-hour overnight spacewalk that began Thursday night. With the pallet's mistake now worked around, STS-123 mission specialists Linnehan and Mike Foreman are slated to attach each of Dextre's two 775-pound (352-kilogram) arms Saturday night.
Shuttle Endeavour and its seven-astronaut crew launched from Cape Canaveral, Fla.'s Kennedy Space Center on March 11 and docked at the space station on March 13. The 100-ton orbiter is slated to return to Earth on March 26.
NASA is broadcasting Endeavour's STS-123 mission live on NASA TV. Click here for SPACE.com's shuttle mission coverage and NASA TV feed.
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