US shuttle grounded until November

The US shuttle fleet will not return to space until November at the earliest, Nasa has announced.

A September launch was cancelled as engineers work to establish why large chunks of foam debris fell off the Discovery’s fuel tank.

Unlike Columbia, which was doomed by a similar problem on re-entry to the Earth’s atmosphere in 2003, Discovery narrowly missed being hit by the foam.

A Nasa spokesman said the September launch of Atlantis for a second test mission had been postponed indefinitely.

“I am confident that we will figure out the problem and launch again, but I wouldn’t like to say when,” he said.

The next available window is November, but after that the chance will not arise until January or more likely, March.

Nasa suspended all shuttle flights when cameras depicted a piece of insulating foam break off the external fuel tank on Discovery’s ascent.

The persistent problem poses a significant threat to the shuttle programme which is already on a tight schedule.

The entire fleet is due to retire in 2010 but by then Nasa had intended to complete construction of the international space station.

The fleet was grounded for two and a half years after Columbia disintegrated just minutes from home, killing all seven astronauts on board.

Nasa invested more than a billion dollars on the subsequent investigation and vowed at the time that it would never happen again.

Bill Gerstenmaier, a foam investigation expert, has now conceded that there may not be one answer and that they may never prevent small amounts of foam coming loose.