Astronauts install porch on ISS

US astronauts Dave Wolf and Timothy Kopra completed a five-hour and 32-minute spacewalk Saturday to prepare the way for astronauts using a robotic arm inside the station to attach the outdoor shelf to the Kibo module.It was the first of five spacewalks during Endeavour's mission that are among the most complex in the 11-year history of the ISS.The porch, delivered to the station in Endeavour's cargo bay, will be used to expose scientific experiments to the extremities of space through X-ray cameras and studies of cosmic dust.Tesuro Yokoyama, deputy project manager of the Kibo effort for the Japanese Space Agency, called the installation a "proud moment".During the spacewalk, Wolf and Kopra prepared berthing mechanisms on the Kibo and the Japanese Exposed Facility - as the "porch" is officially known - and did other work to exterior cargo storage areas. The only problem during the work was a problem with the microphones in the spacewalkers helmets that made communication between the astronauts and the ground difficult.Astronauts Mark Polansky and Canadian Julie Payette used the shuttle's robotic arm to remove the porch from the shuttle and hand it off to the station's arm, operated by Doug Hurley and Japanese astronaut Koichi Wakata, for installation.Hours after the installation power and communications had been made to Kibo's new exposed area with operations there to begin shortly, Yokoyama said. The porch completes the construction of the Kibo module.On Sunday, robotic work was to continue with the shuttle's robotic arm being used unload spare equipment from the cargo bay to be stored outside the ISS. Astronauts will also work to repair exercise equipment inside the station.The shuttle Endeavour docked Friday at the space station, providing a record crowd of 13 astronauts - the largest ever in the space station history. All five international partners - Russia, Canada, Japan, the European Space Agency and the US - have astronauts at the station.In May, the ISS crew doubled its capacity to six permanent residents. Endeavour is carrying seven astronauts, including Kopra, who is the replacement for Wakata. Wakata will return to Earth with the shuttle crew.During subsequent spacewalks slated for every other day in the 16-day mission, the X-ray cameras and other equipment will be secured on the exposed porch.Endeavour suffered some damage during launch on Wednesday when insulation broke free from the external fuel tank and hit three heat-resistant tiles on the shuttle's underside.But the damage was dismissed as superficial by the associate administrator for space operations, William H. Gerstenmaier. As has become routine since the 2003 Columbia disaster, Endeavour pirouetted in a back flip before docking at the space station for a high-resolution image from station cameras of the tiles on its underbelly.The space shuttle programme will be closed down next year, leaving only Russia's Soyuz as transport to the station.NASA is building a new spacecraft Orion to return to the moon by 2015 and prepare launches into space from there to nearby planets like Mars.