12/10/13 Presidents and prime ministers, celebrities and royals joined tens of thousands of South Africans to pay tribute to Nelson Mandela on Tuesday, in a memorial service celebrating a man seen as a global symbol of reconciliation.In what has been billed as one of the largest gatherings of global leaders in recent history, world leaders from President Barack Obama to Cuba's Raul Castro gathered alongside street sweepers, actors and religious figures to pay tribute to nelson Mandela who died last Thursday, aged 95. 12/11/13 didnt do a journal 12/12/13 NASA scaled back operations on the International Space Station on Wednesday after discovering a problem with a cooling system.A pump on one of the station's two external cooling loops shut down after hitting a temperature limit, NASA said.Teams worked to get the cooling loop back up and running, NASA said. Experts suspect a malfunctioning valve may have caused the problem, but they're still trying to figure out how to fix it.