from ap: The astronauts aboard the shuttle-station complex are celebrating the 40th anniversary of man's first moon landing with their own spacewalk. Late Monday morning, David Wolf and Thomas Marshburn ventured out to hook spare parts to the international space station. It is the second spacewalk in three days, and it's taking place 40 years to the day that Neil Armstrong and Buzz Aldrin walked on the moon. "How cool," is how one shuttle astronaut described it. The space station crew, meanwhile, is working on a broken toilet that malfunctioned Sunday. For the time being, the 13 astronauts are lining up at the two good toilets, one on the station and one on Endeavour. NASA says it's not yet a serious problem.