March 14, 2008
Astronauts Complete 7-Hour Spacewalk
Astronauts from four countries, two of them on an overnight spacewalk, joined forces to begin the assembly of a Canadian robot outside the international space station and attach a new Japanese module.
The outing by astronauts Rick Linnehan and Garrett Reisman drew to a close today just after 3 a.m. CDT, spanning seven hours.
The $209 million robotic handiman named Dextre arrived at the station late Wednesday in pieces packed aboard the shuttle Endeavour. The stowage module, the first piece of a $1 billion Japanese science laboratory, rode along side the disassembled robot in the shuttle's cargo bay.
The linkup united 10 astronauts aboard the two space ships from the United States, Japan, France and Russia for an ambitious 12-day construction session.
After disconnecting power cables to free the 14-foot-long stowage module from the shuttle, Linnehan and Reisman began to assemble the mechanical handiman by fastening hands to arms. When fully assembled, Dextre will rise to 12 feet with two arms that reach out 11 feet.
As envisioned by his Canadian creators, Dextre will take over some of the repair work outside the station that is normally assigned to spacewalking astronauts.
Spacewalks late Saturday and Monday will be needed to finish putting the robot together.
While they worked with the robot, Japanese astronaut Takao Doi , hoisted the new module from Endeavour using the shutle's robot to a temporary perch on the space station. The stowage compartment is part of Japan's Kibo lab.
Kibo's cornerstone is a boxcar-sized enclosure in which astronauts can conduct biology and physics experiments. The enclosure is scheduled for launching to the station aboard the shuttle Discovery in late May.
Work with Dextre got off to a disappointing start early Thursday, as the shuttle crew moved a pallet with the robot's torso, arms and hands from the shuttle to a worksite outside the station.
Efforts to power up the robot failed.
Canadian engineers believe a software patch will eliminate a problem that keeps Dextre from responding to the startup command. A patch solving the problem was to be tried later today .
"I don't think this is a long term issue," LeRoy Cain , who chairs NASA's mission management team, said Thursday. "We don't have our hair on fire."
The power is critical to the activation of heaters that warm electronic circuitry in the robots new hands.
The overnight outing was Linnehan's fourth spacewalk, Reisman's first.
They made the most to the outing to sightsee.
"Wow. wow, wow. What are we going over now," Linnehan exclaimed at one point. "Pretty amazing. It could be Chicago, it could be the lake. Wow."
Reisman, a New Jersey native, was just as impressed.
"New York. Long Island. You can see the whole thing," he said. "It's amazing."
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