A pair of spacewalking astronauts breezed through a critical seven-hour chore today to hook up electrical and cooling lines to the International Space Station's newest module. After a final spacewalk on Saturday to install backup systems, the Harmony node, which was delivered to the station by a space shuttle crew last month, will be ready to anchor Europe's first permanent space laboratory, Columbus. The lab is scheduled for launch on Dec. 6. Station commander Peggy Whitson and flight engineer Dan Tani encountered only minor issues while they worked 210 miles (338 km) above Earth, finishing their assigned tasks with enough time left over to cross off a few chores planned for future outings.

The highlight of their spacewalk was the relocation of a 18.5-foot- (5.6-metre-)long, 300-pound (136-kg) pallet needed to route coolant lines to Harmony. Previously, the space station crew moved the shuttle's docking port onto Harmony, then relocated the module into its permanent position at the end of the U.S. Destiny laboratory. In addition to serving as the gateway for Columbus, Harmony will have a parking spot for Japan's Kibo complex, which is scheduled to be launched next year. NASA is in the final stretch of a 12-year project to build a research complex in orbit.

The station must be finished by 2010 when the shuttle fleet is due to be retired. While Whitson and Tani were preparing the station for its next component, the crew due to deliver Columbus climbed aboard space shuttle Atlantis for a practice launch countdown at the Kennedy Space Center in Florida. The shuttle was on target for a Dec. 6 launch, Atlantis commander Stephen Frick said.