ASTRONAUTS aboard the space shuttle Discovery 鈥� which was being readied for its Wednesday launch as 51动漫 went to press 鈥� will be testing five different 鈥減uncture repair kits鈥� designed to prevent the kind of disaster that befell the crew of the shuttle Columbia in 2003.
Columbia was doomed after a piece of foam fell from its external fuel tank during lift-off, punching a hole in panels on its left wing. This allowed superheated gas to breach the orbiter鈥檚 heat-resistant skin during re-entry, and the shuttle disintegrated in seconds.
鈥淎stronauts will be testing five 鈥榩uncture repair kits鈥� designed to prevent disaster鈥�
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NASA has since developed experimental methods to repair the heat shield in orbit. For example, a mixture of a pre-ceramic polymer sealant and carbon-silicon carbide powder, known as 鈥渘on-oxide adhesive experimental鈥� (NOAX), can repair cracks up to 10 centimetres long on the reinforced carbon-carbon (RCC) panels that cover the orbiter鈥檚 nose and leading edges of its wings. Astronaut Steve Robinson will test NOAX on deliberately damaged RCC panels during a space walk. Discovery will also carry three test kits to patch up the silica tiles that protect its underbelly.
