September 18, 2007—NASA has one eye on Discovery’s hydraulics and the other on the calendar as the agency tries to keep the Shuttle on track for its October 23^rd launch date.

Last Friday, engineers spotted hydraulic fluid dripping from the right main landing gear. During touchdown, this set of tires pops out from underneath the Shuttle’s right hand wing to help cushion the landing. The crew of last summer’s STS-121 mission is pictured here next to Discovery’s right handing main landing gear (Yes, that’s Astronaut Lisa Nowak standing fourth from the left). This photo was taken months before the current hydraulic problem cropped up.

Here’s the numbers problem for NASA. Fixing the leaky seals could take anywhere from a week to eleven days. The agency has only five days of wiggle room when you factor in all the time needed to bolt the Shuttle to its external fuel tank and boosters, get the vehicle to the pad, test all the connections, and have the Astronauts down for one last practice session---that leaves you only five contingency days to work with.

NASA’s trying to shave the repair time down by having its own engineers replace the seals, while technicians from Shuttle contractor Goodrich pack their bags and head to KSC to finish the work. Mission managers say repair crews usually work faster than the original estimates, so the actual hit to the launch date won’t be known for days.

More to come.