Astronauts test handyman robot's brakes

Dextre's left wrist had a little trouble braking on Monday as astronauts aboard the International Space Station tested the $200-million Canadian-built robot.

But the wrist's slip, a touch more than engineers had hoped for, didn't concern officials as all other brakes passed the test.

"In the long term it's not going to affect the operation of Dextre in any significant way," said Pierre Jean, Canada's acting space station program manager.

Astronauts flexed the robot's arms and moved them into position in preparation for Monday night's spacewalk, when Richard Linnehan and Robert Behnken plan to add a tool holster and other peripherals to the special purpose dexterous manipulator.

Dextre was designed to take over some of the duties of spacewalking astronauts, performing tasks that require heavy lifting but a finer touch than that of the station's main robotic arm, the Canadarm 2.

But so far, Dextre has required some handholding of its own.

A power cable malfunctioned Friday so the robot had to be hooked up to the Canadarm 2 before it could start up.

And on Sunday, astronauts had use a pry bar and brute force to free one of the arms from the transport bed where it was latched down for launch.

Dextre came to the station aboard the space shuttle Endeavour, which is docked for a nearly two-week visit that includes plans for five spacewalks.

While the two astronauts prepared for Friday night's spacewalk, the other crew members stowed equipment brought to the station aboard the storage compartment segment of Japan's Kibo lab, which was installed last week. The shuttle Discovery will deliver the main piece of the $1-billion lab in May.