Astronauts overcome hurdles in rewiring station’s new robot arm
CAPE CANAVERAL, Fla. (AP) – For the second time this week, two space shuttle astronauts floated outside Tuesday and hooked up cables that sent power coursing through the international space station’s new 58-foot robot arm.
To NASA’s relief, Endeavour spacewalkers Scott Parazynski and Chris Hadfield managed to get both power lines working, after slaving over cable connections.
”Hip, hip, hooray,” the spacewalkers cheered when the backup power line came to life. Applause filled the room at Mission Control.
Only one power routing is needed to operate the robot arm, a billion-dollar, two-handed construction crane that is needed to finish building the space station. But NASA wanted both lines up and running in case one failed.
That wasn’t the only problem during the spacewalk, which lasted 7 hours, an hour longer than planned.
A connector came apart in Hadfield’s hands after he removed an old radio antenna from the space station, and the cap floated into a berthing port. He could not reach the piece. ”If only there was someone out here with long arms,” he said.
Later, the petals of the port were opened one by one, in hopes the cap would float out. ”Like a lot of things in zero-g, it’s drifted off into some inaccessible corner and won’t come out until it’s ready,” Hadfield reported.
NASA officials said the metal cap – about the size of a stack of seven quarters – could interfere when the next space station piece is attached to that berthing port in two months. ”There are going to be a lot of discussions about that in the coming days because it is a concern,” said John Curry, the lead station flight director.
Hadfield also had trouble removing a video signal converter from the packing cradle for the robot arm. He turned the release bolt 26 times, 15 times more than he was supposed to, and still the converter would not come off. He had to give up on that, too.
During a spacewalk on Sunday, Parazynski and Hadfield installed the robot arm on a temporary mount on space station Alpha. One of the arm’s hands let go of that mount Monday and reached over and clamped down on a power and control socket 24 feet away, its base for the next year. The spacewalkers connected four cables at the socket on Tuesday, to provide not only power to the arm but computer data and video.
Power began flowing through the primary routing as soon as Parazynski hooked it up. But the backup power circuit remained dead until Parazynski and Hadfield disconnected and then reattached the cable hookups on both ends. NASA suspects one of the connectors was not bolted down tightly during the last shuttle mission.
”It took a little longer and we sort of went into extra innings, but we came out ahead in the end,” said shuttle flight director Phil Engelauf.
With the problem finally solved, space station residents Jim Voss and Susan Helms commanded the robot arm to release itself from the temporary mount. That hand, now free, continued to clutch the 3,000-pound packing crate, or pallet, that the arm was launched in.
”It’s beautiful to see the Big Arm moving the pallet around,” Canadian Hadfield said of the Canadian-built arm. ”Big relief.”
The robot arm will hand the crate to space shuttle Endeavour’s smaller robot arm on Wednesday, and the crate will be returned to Earth next week. Its first big workout will be to attach a pressure chamber for future spacewalkers, due to arrive in June.
Once the Canadian Space Agency sends up more power and control sockets, the robot arm will be able to move like an inchworm across the entire space station to perform chores.
Despite all the spacewalking action, Parazynski and Hadfield found time to admire the sights 240 miles below. They were oohing and aahing at lightning over Southeast Asia when crewmate John Phillips issued a gentle scolding from inside.
”Hey, Scott, I sent you up there actually just to look at the lightning,” Phillips said, urging them both to get back to work.
They did, laughing and enjoying every minute of it.
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