Two Discovery shuttle astronauts undertook the first spacewalk of the current mission at the International Space early today, checking off a list of outside chores aboard the orbiting laboratory, according to dpa. The duo Clay Anderson and Rick Mastracchio began work to change out an ammonia tank that is part of the ISS's cooling system and replaced a malfunctioning gyroscope, which helps keep the station level as it orbits Earth. The walk lasted six hours and 27 minutes, ending at 7:58 am (1158 GMT). Two more spacewalks are planned on Sunday and Tuesday before Discovery's scheduled undocking on April 16 to begin its homeward journey. On Thursday, crew members of Discovery began unloading the Italian-built Leonardo container, which was packed full of 8 tons of cargo, including experiments, a small fitness studio for the station crew, an observation module with cameras and sensors and a ream of scientific instruments. Discovery took off Monday from Cape Canaveral, Florida, into a stunning sunrise, providing a picturesque launch watched by many on the beach. The planned 13-day mission is to be followed by only three more shuttle missions before the ageing fleet of spacecraft is retired for good by year's end or early next year. That will leave only the Russia Soyuz craft for human transport into space.
