WASHINGTON, Sept. 17 (Xinhua) -- NASA shuttle managers decided on Monday to repair a leaking hydraulic seal of the space shuttle Discovery, which may delay its scheduled October flight.

Technicians will begin repair work Wednesday on the leaking hydraulic seal in Discovery's right main-gear strut, NASA said at a meeting on Monday afternoon.

NASA shuttle managers will assess the ongoing repair work to decide how it might affect Discovery's Oct. 23 target launch date.

The struts act as shock absorbers during the shuttle's landing. The problem cropped up late last week during the preflight inspection by technicians, and the leaking may have arisen during the landing of the shuttle's last mission in December, 2006.

To remove the main landing gear strut and replace seals requires disconnecting and replacing the brakes and tires, disconnecting and reconnecting instruments and other requirements to allow access to the strut.

At the same meeting, NASA also officially decided to add an additional spacewalk to Discovery's mission, bringing the total to five. On the extra spacewalk, astronauts will test tile heat shield repair techniques, extending the mission to 14 days.