Astronauts aboard the space shuttle Endeavour packed gear and checked their spaceship's landing systems on Monday in preparation for a touchdown on Tuesday at the Kennedy Space Center in Florida.
NASA clipped a day off of Endeavour's planned 14-day construction mission to the International Space Station when it appeared Hurricane Dean could force evacuation of the shuttle flight control center in Houston, Texas. The monster storm was predicted to blast Mexico's Yucatan Peninsula with 150 mph (240 kph) winds, before cutting across the Gulf of Mexico and slamming into Mexico's central coast.
With the Johnson Space Center in Houston apparently spared from the storm, NASA could decide to leave Endeavour in orbit if poor weather or technical problems prevent landing on Tuesday. The first of two landing opportunities at the Kennedy Space Center is at 12:32 pm EDT/1632 GMT on Tuesday. Meteorologists expect good weather with mostly clear skies and light winds.
Shuttle commander Scott Kelly, pilot Charles Hobaugh and flight engineer Rick Mastracchio on Monday tested Endeavour's steering jets and body flaps, which are used when the shuttle leaves orbit and glides through the atmosphere for landing.
The shuttle is returning with a small tear in its heat shield, caused when a piece of foam broke off its fuel tank during launch on August 8 and smashed into the ship's underside.
After six days of evaluations and tests, NASA determined the 3-inch (8 cm) gash posed no threat to the crew or the shuttle and decided in-flight repairs were not needed. The crew completed four other spacewalks to install a new beam to the station's external backbone, replaced a failed gyroscope, which is used to keep the outpost properly positioned without chemical rocket firings, and prepared the complex for its first new modules in six years.
Astronauts are scheduled to deliver and install a connecting hub named Harmony during NASA's next shuttle mission scheduled for October. But before that can happen, managers need to determine if more modifications to the fuel tanks are needed to prevent insulation from flying off during launch.
A chunk of foam debris hit the shuttle Columbia during launch and damaged its left wing. NASA did not suspect or look for any damage and the shuttle broke apart as it flew through the atmosphere for landing on February 1, 2003, killing the seven astronauts aboard.
Endeavour's crew includes astronaut Barbara Morgan, a former teacher who originally trained to fly in 1985 as the backup to Christa McAuliffe, a teacher who flew on the ill-fated Challenger mission in January 1986. Morgan became an astronaut to fulfil McAuliffe's goal of spotlighting educational opportunities during space flight. She plans to use her experience in orbit to develop activities and curricula for classroom teachers.