Space shuttle Discovery set for final mission

The 39th and final mission of the Space Shuttle Discovery is scheduled to launch from the Kennedy Space Center at 4:50 p.m. Thursday for a trip to deliver equipment and spare parts to the International Space Station.

The mission, designated STS 133, will deliver a Permanent Multipurpose Module, providing 2,472 additional cubic-feet of space for storage and other uses. An Express Logistics Carrier, a platform designed to support equipment on the outside of the station, will also be delivered and installed.

"We all take immense pride in the work of the team and the shuttle, and we look forward to a successful mission," said Stephen Payne, NASA's launch test director, during Tuesday's pre-launch briefing.

STS 133 was originally set for launch on Nov. 5, but was delayed by a hydrogen leak. "There was an actual leak there that scrubbed the launch," NASA spokesperson Candrea Thomas said. "While investigating the leak, they also found some cracks." The small cracks were found in the mid-section of the external fuel tank, on the tops of two aluminum brackets. The launch was pushed back to Nov. 30, but additional cracks were found and Discovery was rolled back to the Vehicle Assembly Building for repairs.

Payne said the external tank is "stronger than ever." He said some additional inspections will take place before launch. "We don't expect any problems. Our launch countdown is proceeding on schedule," Payne said.

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Weather is unlikely to be a problem for the six-member crew, according to NASA weather officer Katherine Winters. "Overall, the weather is good and is expected to remain good through the pre-launch window," Winters said. "There's just a 20 percent chance of weather prohibiting launch."

Payne said the last Discovery launch, and the end of the shuttle era, "has generated a lot of interest. People are starting to realize they either see one now, or they don't get to see one. It ought to be a good show," Payne said. "I'm sure we'll have a full house."