Discovery's tank to get reinforcement before flight

Shuttle program managers today gave the go-ahead to proceed with some modifications to Discovery's external tank in preparation for a flight still targeted for early February.

Technicians plan to reinforce 34 of the 108 structural support beams called "stringers" on the tank' mid-section, a handful of which were found to have cracked after a Nov. 5 launch attempt.

The stringers being reinforced are located on two panels where solid rocket boosters connect to the intertank and are the ones subjected to the most stress during flight. They do not include the five stringers that have shown cracks, which are being repaired separately.

The modification being implemented fastens a small strip of metal called a "radius block" to the tops of the stringers to limit the amount they flex.

NASA expects the work to be completed within a week, preserving the option of launching Discovery during an eight-day window that opens Feb. 3.

However, the next program meeting on Thursday will review more engineering analysis that could lead to a decision to reinforce the tops of all of the stringers. That would push Discovery's launch into the next window, which opens Feb. 27.