Don't stop, say shuttle families

The families of the seven astronauts who lost their lives in the Columbia shuttle disaster said yesterday that their personal tragedy should not derail plans for the exploration of space.

"Although we grieve deeply ... the bold exploration of space must go on," the families of the dead crew members said in a statement. It was read out on NBC television by Evelyn Husband, the widow of the shuttle commander, Rick Husband. "Once the root cause of this tragedy is found and corrected, the legacy of Columbia must carry on for the benefit of our children and yours."

Nasa investigators suggested that the leading theory as to why the spacecraft exploded as it re-entered the Earth's atmosphere on Saturday was damage to Columbia's thermal tiles during lift-off. Nasa is focusing on possible damage to thermal panels on the left wing of the shuttle, which may have been damaged by a piece of insulation that broke free during the blast-off on 16 January.

Last week a Nasa engineering team circulated an internal memo that estimated the launch accident had caused a gash of between 7.5 and 30 inches in the shuttle's left wing.