NASA: Space Shuttle Endeavour to Land One Day Early

HOUSTON -- NASA's space shuttle Endeavour will land one day early to avoid the possible impacts of Hurricane Dean, mission managers said Saturday.

Endeavour is now set to land on Tuesday at the Kennedy Space Center in Florida due to the looming threat of Hurricane Dean to NASA's shuttle and space station Mission Control centers here at the Johnson Space Center (JSC).

"End of mission day is now Tuesday," Cain told reporters here at JSC. "That's our first landing day."

Endeavour's seven STS-118 astronauts are now set to undock from the International Space Station (ISS) at 7:57 a.m. EDT (1157 GMT) Sunday and land at 12:30 p.m. EDT (1630 GMT) Tuesday in Florida.

Spacewalkers Dave Williams and Clayton Anderson cut short a planned 6.5-hour spacewalk earlier Saturday to prepare for the earlier undocking and landing, but not before the spaceflyers caught sight of Hurricane Dean while working outside the ISS.

"Holy smokes," Anderson told Williams. "Did you see the eye?"

As of late Saturday, Hurricane Dean remained a strong category four storm with winds blowing up to 150 miles per hour (240 kph) as it made its way west-northwest across the Caribbean Sea, according to the National Hurricane Center. The storm is currently headed towards the Gulf Coast, with some forecasts predicting landfall in southern Texas at its northernmost point.

Cain said NASA's greatest concern is that Dean could force an evacuation of its Mission Control centers just in time for Endeavour's previously planned Wednesday landing.

"I would defy just about anybody to tell me at this point that there is zero, or even extremely low probability or possibility, that this storm is going to come here," Cain said, adding that it's still too early to predict what Dean will do. "We've all watched these storms before, we're all aware of what they can and have done."

If Dean threatens mission operations in Houston by about Monday, NASA will call up backup landing sites at California's Edwards Air Force Base and New Mexico's White Sands Space Harbor for a definite return to Earth Tuesday, Cain said.

But if the storm does not force critical flight controllers to evacuate Mission Control, and bad weather prevents a Florida landing on Tuesday, Endeavour could circle Earth an extra day, he added.

NASA's International Space Station (ISS) mission operations can shift to Russia's Mission Control near Moscow during hurricanes, with a backup U.S. team set up outside of Houston. The scenario was successfully implemented in September 2005 during Hurricane Rita.

For shuttle flights, the agency can set up a backup Mission Control in a launch firing room at the Kennedy Space Center, but the facilities are not as robust for landing support as those in Houston.

Endeavour's earlier landing day comes after NASA cleared concerns over a small, but deep, gouge in the orbiter's belly-mounted heat shield.

Commanded by veteran shuttle flyer Scott Kelly, Endeavour's STS-118 crew delivered about 5,000 pounds (2,267 kilograms) of cargo, a new spare parts platform and a new starboard side girder to the ISS. The crew also includes teacher-turned-astronaut Barbara Morgan, who served as NASA's backup to Teacher in Space Christa McAuliffe before the 1986 Challenger accident.

Hatches between the two spacecraft were shut earlier today after a brief farewell ceremony between the Endeavour astronauts and the station's Expedition 15 crew.

"We're going to be here for about another two months," Expedition 15 commander Fyodor Yurchikhin told the departing shuttle astronauts. "Come back again!"

NASA is broadcasting Endeavour's STS-118 mission live on NASA TV. Click here for mission updates and SPACE.com's NASA TV feed.

• VIDEO: STS-116 Mission Profile: Fourth Spacewalk
• VIDEO: Endeavour Shuttle Tile Damage
• Complete Space Shuttle Mission Coverage