Work began 3 January to repair four cracks in three support beams on Space Shuttle Discovery's external fuel tank.

NASA is using a methodology similar to the repairs made on cracks found on two of the 21ft-long (67.4m) stringers after Discovery's Nov. 5 launch attempt, the US space agency says.

The additional cracks were found after an extensive scan of all of Discovery's 108 aluminium stringers using X-ray image scans after the shuttle was moved back inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida after a series of aborted launch attempts late last year.

The repair work is expected to take two to three days, NASA says.

 Discovery repairs in VAB

 © NASA

Programme managers also began another round of stringer imaging on 3 January, this time using a backscatter methodology. Any further work will be evaluated thoroughly early next week after additional data is reviewed, NASA says.

The next launch window for STS-133 - which was originally planned for 1 November - begins 3 February and extends through 10 February. The flight, to be Discovery's last, will deliver a pressurised logistics module called Leonardo and a 136kg (300lb) humanoid robot to the International Space Station.

Source: Flight International

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