This story was updated at 7:32 p.m. EST.
HOUSTON — Two spacewalking astronauts helped deliver a new European module to the International Space Station (ISS) Monday to boost the orbiting laboratory's research facilities.
Atlantis shuttle astronauts Rex Walheim and Stanley Love spent almost eight hours working to help attach the European Space Agency's (ESA) 1.4 billion euro ($2 billion) Columbus laboratory to the ISS and add a new room to the high-flying outpost.
"Houston, Munich, the European Columbus laboratory module is now a part of the ISS," said French astronaut Leopold Eyharts, of the ESA, from the station as the new lab arrived at 4:44 p.m. EST (2144 GMT).
With the exception of stubborn power cables, which waylaid the spacewalkers for an hour, the orbital work appeared to go smoothly despite a last-minute astronaut switch that put Love in a slot originally reserved for German astronaut Hans Schlegel, of the ESA.
Mission managers replaced Schlegel with Love on Saturday due to an undisclosed medical issue. Schlegel assisted Atlantis pilot Alan Poindexter to choreograph today's spacewalk from inside the shuttle and is expected to take part in the mission's second spacewalk on Wednesday.
"I think the crew really stepped up to the plate," said Anna Jarvis, NASA's lead spacewalk officer for the mission.
Monday's spacewalk, the first of three planned for Atlantis' planned 12-day mission, began at 9:13 a.m. EST (1413 GMT) and ran seven hours, 58 minutes in duration. It marked the first spacewalk for Love and the third for Walheim.
"Welcome to spacewalking, buddy," Walheim told Love.
"It's awesome," Love said.
Columbus finds a new home
Astronauts plan to open the ESA's Columbus lab on Tuesday to christen the 27-foot (7-meter) laboratory and outfit it for orbital flight. The new module is about 14.7-feet (4.5-meters) wide and adds an extra 2,648 cubic feet (75 cubic meters) of breathing room aboard the ISS.
"There is a sight that everybody in Europe has been looking forward to for a very, very long time," said Alan Thirkettle, ISS program manager for the ESA, after Columbus' installation. "She looks beautiful."
Columbus is built to hold a total of 16 equipment racks, 10 of which will be devoted to scientific research. A new ESA control center, based in Oberpfaffenhofen, Germany just outside of Munich, will oversee the module's daily operations.
"We are opening a new chapter for ESA starting with the utilization of Columbus," said ESA director general Jean-Jacques Dordain when the module launched last week, adding that European researchers and engineers have spent two decades working for today's delivery. "Now they will be able to reap the benefits."
In addition to the science racks launched with the module, Walheim and Love will add two exterior experiments to study the sun and monitor the space environment during a planned Friday excursion.
ESA officials named Columbus after Christopher Columbus with the hope of launching it into orbit in 1992 during the 500th anniversary of the explorer's historic 1492 voyage to the New World. But delays and redesigns to the module, the ISS project overall and NASA's recovery from two shuttle disasters pushed the new lab's launch to 2008.
"Columbus is officially docked to the space station, joining the world's voyage of exploration of the new New World," NASA commentator Pat Ryan said.
Eyharts will spend the next month commissioning Columbus as a member of the station's Expedition 16 crew. He helped STS-122 mission specialists Leland Melvin and Dan Tani attach the new lab to the space station using the outpost's Canadarm2 robotic arm.
"Wow, look at Columbus coming in!" Walheim exclaimed to station commander Peggy Whitson and other astronauts aboard the ISS and Atlantis. "Give Peggy a new room for her house."
Kirk Shireman, NASA's deputy station program chief, said mission managers are debating whether to add an extra day to Atlantis' already extended STS-122 flight to allow extra time to commission the Columbus lab."
Space station support
During their spacewalk, Walheim and Love attached a grapple fixture to Columbus to provide a handle for the station's robotic arm. They also loosened bolts and disconnected cables on a spent nitrogen tank serving the station's cooling system, priming it for replacement during a Wednesday spacewalk.
Love also spotted what appeared to be a ding, possibly caused by orbital debris or a micrometeorite, on a handrail near the station's Quest airlock.
"Looks to me like a little impact crater," said Love, adding that the blemish appeared to be about 2 millimeters in size. "It is right where everybody grabs on the handrail."
Mission Control asked the spacewalkers to photograph the ding as part of an ongoing survey of areas that may pose a tear hazard to an astronaut's spacesuit gloves.
Monday's spacewalk marked the 102nd dedicated to space station construction, leaving the orbital laboratory about 57 percent complete, mission managers said. By the excursion's close, Walheim racked up 22 hours and 13 minutes of spacewalking time while Love concluded with 7 hours and 58 minutes.
At one point, the astronauts caught sight of NASA's Kennedy Space Center in Cape Canaveral, Fla., while working in orbit.
"What an awesome pass over Florida," said Love, adding that he could see NASA's shuttle landing strip from space. "Oh, wow. Fabulous!"
NASA is broadcasting Atlantis' STS-122 mission live on NASA TV. Click here for SPACE.com's shuttle mission coverage and NASA TV feed.