SPACE CENTER, Houston (AP) _ A 58-foot robot arm on the international space station successfully completed its first major construction job early Sunday when it added a $164 million passageway for spacewalkers to the 230-mile-high outpost.
Station astronaut Susan Helms maneuvered the arm while space shuttle Atlantis astronauts Michael Gernhardt and James Reilly II shepherded the installation from the outside during a spacewalk that lasted six hours, an hour less than planned.
``Again, thanks to everybody up there. Nice flying Susan, and it's really wonderful to see the air lock there,'' Mission Control said.
Atlantis delivered the new 6 1/2-ton air lock to space station Alpha late Friday, a month later than planned as engineers grappled with problems with computers needed to operate the Canadian-built robot arm.
The arm exhibited none of those problems Sunday.
``Good team all around, both the ones up here and the ones on the ground,'' Reilly said.
Gernhardt and Reilly floated out of Atlantis an hour late, but quickly made up for lost time despite Gernhardt's difficulty removing protective covers from the new air lock.
``It was like wrestling a 12-foot alligator and tying it up with a 20-foot snake,'' he said. ``But I think it's under control.''
Reilly, an honorary U.S. marshal since June, felt totally in control. ``Man, I feel like Marshal Dillon with this huge pistol,'' he said, referring to his power tool.
``Well, you are the marshal,'' Gernhardt pointed out.
Helms maneuvered the arm to hoist the air lock out of Atlantis' cargo bay and lift it to its berthing point on the station as shuttle astronaut Janet Kavandi steered a smaller robot arm attached to the shuttle, which transported Gernhardt and Reilly around the complex.
Astronauts and Mission Control got a preview of the arm's successful performance in a dress rehearsal of the air lock installation early Saturday.
The arm was added to the station in April to act as a high-tech construction crane in Alpha's continued growth.
Engineers in the United States and Canada determined that a bad computer card was causing the most persistent trouble in the arm's shoulder joint. Atlantis launched early July 12 with Mission Control confident that the problems were solved.
Two more spacewalks are planned during Atlantis' weeklong visit to install four high-pressure gas tanks on the air lock. The third spacewalk on Thursday will be the first ever from the air lock.
The air lock, a two-room pressure chamber, will enable station astronauts to conduct spacewalks in U.S.-made spacesuits without aid of a shuttle. Until now, they have had to rely on Russian suits because the U.S. outfits are incompatible with Russian systems.