The launch of the US space shuttle Endeavour has been delayed due to bad weather over the Kennedy Space Center in Florida. NASA officials said the delay was caused by a heavy cloud cover over Cape Canaveral and will try again tomorrow morning. The Endeavour mission's main goal is the delivery of the Tranquility module, also known as Node 3, which comes with a multi-window cupola attached. NASA said with Endeavour's delivery of Tranquility and its attached cupola, the International Space Station will be 90 per cent complete. Endeavour's 13-day mission, which also includes three spacewalks, will be the last night launch for a shuttle. The four missions that follow Endeavour will all take place in daylight hours. The shuttle mission is the first since President Barack Obama announced a new vision for US human space exploration.