Space debris hit shuttle

Damage from debris has been Nasa's top safety issue since the destruction of shuttle Columbia in February 2003, when insulating foam came off the ship's fuel tank during launch and punched a hole in the shuttle's protective heat shield.

The radiator damage, which measures slightly more than one-tenth of an inch in diameter, was found during routine post-landing inspections at the Kennedy Space Centre in Florida, Nasa spokeswoman Jessica Rye said.