US: Nasa was facing the possibility of another humiliating delay to its space shuttle programme last night after safety inspectors found a large crack and a missing chunk in the insulation foam of Discovery's external fuel tank as it stood on the launch pad.
The countdown to today's Independence Day launch, rescheduled after two successive weather delays, was continuing but mission managers were facing a race against time to complete a full inspection.
The problem of foam has plagued the space agency since the 2003 Columbia disaster, when a briefcase-sized chunk peeled off at lift-off and struck a hole in the wing. It allowed deadly hot gases to seep in at re-entry, destroying the shuttle and killing seven astronauts.
A smaller piece narrowly avoided missing Discovery during its first return to flight mission last July, forcing Nasa to ground the shuttle fleet for another year. "The bottom line is if the engineering and safety teams do not get comfortable, we'll take [ another] day and if we need to do a repair, we'll take the time to do it," said John Shannon, chairman of the mission management team.
He said the missing chunk of foam, about three inches long, was not considered a hazard to flight. But the fact that the agency is still wrestling with foam issues despite $1.3 billion in safety upgrades since the Columbia disaster reopens the debate about the reliability of the ageing shuttle fleet. - (Guardian service)