Shuttle Crew to Undock from Space Station

HOUSTON - Seven astronauts will cast off from the International Space Station (ISS) aboard their shuttle Endeavour Sunday as NASA keeps watch on Hurricane Dean.

Endeavour's STS-118 astronauts are due to undock from the space station at 7:57 a.m. EDT (1157 GMT), one day earlier than initially planned, to avoid complications on Earth should Hurricane Dean interrupt Mission Control operations later this week.

"We feel like it would not have been responsible for us to go past an opportunity to, in this case, land a day early," said LeRoy Cain, NASA's STS-118 mission management team chairman, in a Saturday briefing.

Commanded by veteran shuttle flyer Scott Kelly, Endeavour's STS-118 crew hauled a total of 4,270 pounds (1,936 kilograms) of cargo to the ISS alongside a new external spare parts platform and a new starboard girder for the orbital laboratory's backbone-like main truss, NASA said Saturday.

Kelly and his crewmates shared hearty hugs with the station's three-man Expedition 15 crew Saturday, particularly with flight engineer Clayton Anderson, as they closed the hatches between their two spacecraft after just over eight days of docked activities. Anderson was originally assigned to launch to the ISS with Endeavour's STS-118 crew, but was later moved to an earlier mission.

"You guys were my first crew, and you'll always be my first crew," Anderson said during a farewell ceremony Saturday. "Thanks for everything."

In addition to continuing space station construction, Endeavour's crew also included the first flight of teacher-turned-astronaut Barbara Morgan, who first joined NASA as the backup to Teacher in Space Christa McAuliffe before the 1986 Challenger accident. Morgan rejoined NASA in 1998 as a mission specialist and educator astronaut.

A former Idaho schoolteacher, Morgan delivered a cinnamon basil seeds and a pair of plant growth chambers to the ISS as part of her education mission. She also spoke to students via video links and ham radio, answering questions with her crewmates to describe life in space.

"We know that they're going to love being up here, those that want to," Morgan said of the students while docked at the ISS. "It's a great place."

Divining Dean

Originally slated for a Wednesday Earth return, Endeavour is now set to land Tuesday at 12:29 p.m. EDT (1929 GMT), Cain said.

Mission Control also canceled a planned victory lap of sorts after undocking, in which Endeavour circles the ISS while astronauts photograph the station.

The move frees up some crew time since the spaceflyers will still have to perform a now-standard late inspection of their spacecraft's heat shield later today. NASA has already cleared concerns over a small gouge in one of the orbiter's belly-mounted tiles.

At the heart of the accelerated departure is Hurricane Dean, currently barreling across the Caribbean Sea on course for the Gulf of Mexico. As of late Saturday, the category four hurricane continued on its northwesterly course with maximum wind speeds reaching 150 miles per hour (240 kph), according to the National Hurricane Center.

If the storm veers towards coastal Texas and threatens NASA's shuttle and ISS Mission Control centers, the space agency will call up two backup landing sites - California's Edwards Air Force Base and White Sands Space Harbor in New Mexico - for Endeavour, Cain said.

But if the storm allows, flight controllers will remain here at JSC since it is better equipped to support shuttle landings than its backup site at the Kennedy Space Center.

If Dean does not impact Houston shuttle flight operations, NASA will only try to land Endeavour in Florida Tuesday before calling up alternate runways on Wednesday, Cain added.

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

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