NASA to hold briefing on Discovery launch

The news conference is scheduled for 1:00 pm Central Time (1900 GMT).

Senior NASA officials were briefed on Monday by shuttle managers about the progress on repairs to cracks that were discovered on the 21-foot-long U-shaped aluminum brackets, called stringers, on the shuttle's external fuel tank.

"Managers approved installing small strips of metal, called radius blocks, on the tank's remaining stringers," NASA said in a statement.

"While additional testing and analysis continue, results so far show the modification will provide additional strength to the stringers."

Earlier this month the US space agency postponed the shuttle launch, already pushed back from November to February, to an undetermined date to allow more time for repairs.

Discovery has been plagued by setbacks since its initial launch attempt in November was scrubbed after the cracks were discovered.

NASA has said that the next available window for launch could be from February 27 to March 3.

Another shuttle, Endeavour, is set to take off in April in what will be the last shuttle launch scheduled for the US program.

One more as yet unscheduled launch could take place in the summer before the entire fleet is retired for good.

(c) 2011 AFP