Engineers are assessing an apparent hydraulic leak in the shuttle Discovery's right-side main landing gear strut. If internal seals have to be replaced, launch on a space station assembly mission could slip a few days, officials said today, but they cautioned that it's not yet clear how long such repairs might actually take.

The leak was discovered during routine testing in preparation for the shuttle's rollover from its processing hangar to the Vehicle Assembly Building for attachment to an external fuel tank and solid-fuel boosters. As of Friday, rollout to launch pad 39A was targeted for Sept. 27, setting the stage for launch Oct. 23.

But work to replace the hydraulic seals, if required, would delay rollover and rollout. Even with several days of contingency time in the schedule, launch could be delayed a few days if repairs are ordered. What impact, if any, such work might have on plans to launch the shuttle Atlantis around Dec. 6 is not yet known.

NASA and contractor managers plan to meet Monday to discuss the issue and make a decision on how to proceed.

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