Hurricane threat may bring shuttle home early

HOUSTON (Reuters) - The space shuttle Endeavour could come home a day early from the International Space Station if Hurricane Dean threatens the ground operations center in Houston, NASA officials said on Friday.

"It's not ideal," shuttle commander Scott Kelly told an in-flight press conference. "But we could potentially undock the day after the (Saturday) spacewalk and come home a day early."

The powerful hurricane was barreling northwest through the Caribbean Sea and was expected to clip Mexico's Yucatan Peninsula early next week and then move into the western Gulf of Mexico, potentially menacing the Texas coast.

Kelly and his crewmates also said they support NASA managers' decision to not repair a small but deep gouge in two of Endeavour's belly tiles.

The tiles protect the ship from the intense temperatures experienced during re-entry prior to landing.

"We agree absolutely 100 percent with the decision to not repair the damage. There's a lot of engineering rigor put into making this decision. It took some time but that is because there was a lot of testing," Kelly told reporters gathered at the Johnson Space Center in Houston.

"Even though a repair could potentially buy a little more margin, there is certainly more risk in doing the repair than we're willing to take. We could potentially cause more damage to the underside of the orbiter."

The 3.5-inch (9-cm) gouge was caused by a piece of foam and possibly ice that fell off the shuttle's fuel tank and smashed into the Endeavour's underside during its liftoff on August 8 from the Kennedy Space Center in Florida.

NASA studied the damage for six days before making a decision late on Thursday.

Analysis shows the aluminum skin beneath the tiles would heat to about 340 F (170 C), instead of the usual 300 F (150 C) if the tiles were intact.

Aluminum melts at about 1,200 F (650 C) and the adhesive used to seal the tiles to the skin can withstand temperatures of up to 650 F (345 C), mission manager John Shannon said.

If NASA decides to bring Endeavour home early, the shuttle would undock from the station on Sunday and land at the Kennedy Space Center on Tuesday.

The shuttle arrived at the International Space Station on August 10 to deliver new components and prepare the outpost for the arrival of new modules later this year. A fourth and final spacewalk to complete the work is scheduled for Saturday.