Spacewalkers attach arms to giant robot

Image: spacewalk
Spacewalkers fell an hour behind in their work after a bar on one of the robot's arms proved difficult to dislodge. The nighttime spacewalk came close to be drastically altered due to a power problem on Friday. NASA TV
/ Source: The Associated Press

The space station's gigantic new robot, Dextre, rose like Frankenstein from its transport bed early Sunday, enabling spacewalking astronauts to attach its 11-foot arms.

With a tug from spacewalking astronaut Richard Linnehan, Dextre's body was rotated up 60 degrees, an ideal position for plugging in its arms. The robot looked as though it was sitting up.
"It's really eerie out here. It's pitch black and there's just this big white kind of humanoid-looking thing below me," Linnehan said.

Dextre's hands were attached to its arms during the first spacewalk of Endeavour's international space station trip. This time, astronauts connected the arms to the shoulders, representing the bulk of the walking and working machine.

"Good work guys," astronaut Robert Behnken called out to his colleagues after they hooked up the first arm. "We've got a one-armed monster now." The second arm went on soon afterward.

Spacewalkers Linnehan and Michael Foreman had to use brute force and a pry bar to get one of the robot's arms off the transport bed, where it had been latched down for launch. Two of the bolts wouldn't budge, even when the astronauts banged on them and yanked with all their might.

"We're really having to get medieval on Mr. Dextre," Foreman observed.

Finally, the bolts gave way. But by then, the astronauts had fallen an hour behind in their work.

The nighttime spacewalk came close to being drastically altered or even delayed. For nearly two days, a cable design flaw prevented NASA from getting power to Dextre, lying in pieces on its transport bed.

It wasn't until the astronauts gripped Dextre with the space station's mechanical arm Friday night that the robot got the power it needed to wake up and keep its joints and electronics from freezing.

Once fully assembled, Dextre will stand 12 feet and have a mass of 3,400 pounds. Its shoulder span is nearly 8 feet.

A third spacewalk, on Monday night, will provide Dextre with a tool holster. That ought to do it.

The Canadian-built Dextre — which cost more than $200 million and was flown up on Endeavour — is designed to assist spacewalking astronauts. Its name, in fact, is short for dexterous. The hope is that the robot eventually will take over some of the more punishing chores, like lugging around big replacement parts.

To guard against a robotic mutiny, Mission Control jokingly told the astronauts in their wakeup mail Saturday that some new flight rules were being instituted.

No. 1, "Dextre may not injure a human being or, through inaction, allow a human being to come to harm," Mission Control wrote, quoting from science fiction writer Isaac Asimov. No. 2, "Dextre must obey orders given to it by human beings, except where such orders would conflict with the First Law."

As for Dextre's belated wakeup, Canadian Space Agency officials were reluctant to cast blame. The agency and its main contractor were responsible for designing the cable that failed to relay power to the robot, via its transport bed.

Three more spacewalks are planned during Endeavour's nearly two-week visit to the space station for a total of five. That will be the most spacewalks ever performed during a joint shuttle-station flight.