Europe's long-awaited Columbus laboratory module was the focus Monday of a spacewalk that kicked off at 1413 GMT, with two astronauts paving the way for another expansion of the International Space Station, according to dpa. The first spacewalk of the current Atlantis shuttle mission was delayed by a day after German astronaut Hans Schlegel, 56, had an unspecified "health issue." Although German Space Agency officials said Schlegel had recovered, US astronaut Stanley Love replaced him for the Monday spacewalk alongside US astronaut Rex Walheim. Schlegel however will take over on the second venture into space at 1435 GMT Wednesday, NASA officials said. In the current spacewalk, Love and Walheim are installing a fixture on Columbus to allow the space station's robotic arm to grab the laboratory module and move it from the Atlantis shuttle that docked on Saturday. They will also perform maintenance work outside the station by removing a nitrogen tank assembly that is part of the station's thermal control system. The assembly is to be replaced on Wednesday's spacewalk. Officials at the German Space Agency (DLR) mission control centre in Oberpfaffenhofen in southern Germany said Sunday that Schlegel was in "perfect" shape after readings taken Saturday "called for caution." Space officials would only say the problem was not life- threatening, but there was speculation it could have been minor problems of adjustment to being in space. The mission is being closely watched by European space programme engineers and officials. They have been waiting four years for their Columbus laboratory - Europe's largest contribution to the space station - to be installed. The delay was triggered by the tragic 2003 loss of NASA's Columbia shuttle. The European Space Agency's capsule, built mostly by EADS-Astrium in Bremen, Germany, is intended to expand the scientific research capacity of the orbiting space station. On a third scheduled spacewalk, Walheim and Love are to transfer experiments to the exterior of Columbus and retrieve a gyroscope. As the world's only heavy-lifting spacecraft in operation, the US shuttles are hurrying to finish space station construction so NASA can retire the decades-old transporters in 2010. By that time, construction is expected to have doubled the station's capacity to six astronauts. NASA extended the Atlantis mission by a day to compensate for the spacewalk delay, meaning the shuttle is expected to return to Earth on February 19.
