Nasa emails warned of disaster

Emails written by Nasa engineers hours before the shuttle Columbia blew up warned of the impending tragedy, it was revealed yesterday.

But the memos never reached top-level staff, who had decided the shuttle was fit for landing even though it had been hit by debris shortly after take-off.

The messages sent between staff at Nasa's Johnson Space Centre and its Langley Research Centre even discussed getting the crew to bail out before the wing burned off.

The emails, made public under the Freedom of Information Act, pose questions about whether enough was done to save the seven astronauts who died when Columbia broke up earlier this month.

Many were responses to structural engineer Robert Daugherty's fears that damage to the shuttle could prevent it returning to Earth safely.

He was mainly concerned about the shuttle landing with flat tyres, wing damage - and temperature rises in a wheel arch - all of which are thought to have occurred in the final minutes of the doomed spacecraft's flight.

Nasa spokesman Dave Youngman said the memos merely examined the possible problems that could occur and engineers believed the shuttle would land safely.

'They got together and said "we've looked at all the scenarios". We don't see that it's a concern,' he said.