Science

NASA eyes weather as Endeavour prepares to land

The weather outlook for the space shuttle Endeavour's return to Cape Canaveral, Fla., was fairly good Tuesday morning, although forecasters are keeping an eye on the crosswind.

The weather outlook for the space shuttle Endeavour's return toCape Canaveral, Fla., was fairly good Tuesday morning, although forecasters are keeping an eye on the crosswind.

Endeavour's crew, which includes Canadian astronaut Dave Williams, prepared to land a day early Tuesday because of NASA's concerns about the threat Hurricane Dean could pose to Mission Control.

It's now considered unlikely that Hurricane Dean will hit Endeavour's mission control hub in Houston, Texas,but NASA is nonetheless being cautious.

Endeavour's first landing path would take the crew over the Pacific Ocean, Central America and Cuba before touching down at Cape Canaveralat 12:32 p.m. ET.

If bad weather forces NASA to scrub that landing attempt, the shuttle's second opportunity would include flying over Mexico's Yucatan Peninsula, which was battered Tuesday morning by Hurricane Dean. If the shuttle crosses above the hurricane, it will be too high to feel its effects, NASA said.

Homeward Bound

Endeavour's seven crew members woke early Tuesday to Simon and Garfunkel's Homeward Bound, a tribute from all of their families.

"That's very nice of them to think of that," commander Scott Kelly told Mission Control. "Although it's been a short two weeks, we've accomplished a lot and we still look very much forward to coming home today."

NASA spokesman Bill Jeffs told CBC News that no major activities planned for mission STS-118 will be missed, even though the mission will likely be a day shorter than expected.

He added that the journey had previously been extended by three days after a successful construction project on the space station that allowed the shuttle to stay in orbit longer, so the crew had the time it neededto complete the major mission objectives before Tuesday's planned landing.

Mission managers decided Saturday to play it safe and bring Endeavour back a day early because of the hurricane. NASA could have rushed a skeleton flight control team from Houston to Cape Canaveral, Fla., and had the shuttle land there. But it was reluctant to do so, as that would mean using a scaled-down team.

Bad weather on Earth rarely cuts shuttle missions short. Instead, it often has the opposite effect, keeping shuttles in orbit longer.

Nine-day trip boasts many accomplishments

NASA says the mission has been a success.

"The STS-118 crew members spent almost nine days at the international outpost. They continued the on-orbit construction of the station and transferred tons of cargo between the two spacecraft. The STS-118 crew conducted four spacewalks at the station. The two major objectives were the installation of the S5 and the replacement of a failed attitude control gyroscope," says NASA's website.

Williams performed three spacewalks during this mission, setting a Canadian record for number of spacewalks, topping Chris Hadfield, who performed two in 2001.

Williams also earned the distinction of floating freely in space for longer than any other Canadian. He spent 17 hours, 47 minutes outside the space station during his three spacewalks, bettering Hadfield's total spacewalk time of 14 hours and 56 minutes in 2001.

Early in the mission there had been concern about a small nick in the shuttle's heat-shield tiles caused by a piece of foam that broke away from Endeavour's fuel tank during launch. The astronauts used a laser-tipped boom to hunt for possible micrometeorite damage to the shuttle's wing and nose that might have occurred during the nine days the shuttle was docked to the space station.

On Monday, NASA analyzed close-up laser scans of Endeavour's wings and nose, and cleared the shuttle for re-entry.

With files from Associated Press and Canadian Press