year-old workhorse space shuttle programme will be retired by 2010 due to safety problems exposed in the 2003 Columbia disaster. In that tragedy, foam insulation fell off the rocket fuel tanks on take-off and damaged the fragile ceramic tiles on the low-riding shuttle. At mission's end, as the shuttle re-entered Earth's atmosphere, the broken tiles allowed superheating inside the craft and caused it to explode, killing all seven astronauts on board. --More 2358 Local Time 2058 GMT