Washer Defect Prompts Shuttle Repairs

Seals inside boosters scheduled for takeoff Feb. 22 with the shuttle Atlantis will be replaced because of a defect found in a gasket-like washer used by the shuttle Columbia’s boosters during launch last month, officials said Wednesday.

Technicians also plan to replace a high-pressure hydrogen fuel turbopump mounted on Atlantis’ No. 3 main engine because of welding flaws in a titanium inlet that should have been repaired earlier, NASA spokesman Jerry Berg said.

The seal replacement work is not expected to have any impact on the scheduled launch of Atlantis on a classified military mission. The impact of the pump replacement has not been determined.

Berg said engineers working on the boosters used by Columbia during launch Jan. 9 found a small depression in one of two gasket-like washers between the right-side rocket’s igniter and the “safe-and-arm” device used to arm the rocket for firing.

Such seals are tested before installation by compressing them and then conducting an inspection within 30 minutes to make sure they return to the proper shape. But it was not clear whether the test was performed properly in the case of the flawed seal found in Columbia’s right-side booster.

A review of paper work raised similar questions about the seals on board Atlantis’ boosters. Similar seals have been replaced at the launch pad in the past.