The space shuttle Discovery and its crew of seven are scheduled to return to Earth Monday after nearly two weeks in space.
The U.S. space agency will be watching closely as Discovery begins its descent from orbit at about 740 UTC and re-enters the Earth's atmosphere.
This will be the first shuttle landing since the shuttle Columbia burned up during re-entry in February 2003.
Forecasters are predicting good weather for Discovery's pre-dawn landing at Kennedy Space Center in Florida at about 0846 UTC.
Discovery's seven crew members slept late Sunday after a check of the spacecraft's flight-control systems. Earlier, shuttle commander Eileen Collins and flight entry director LeRoy Cain said they are confident about the shuttle's return.
Today's landing comes after an unprecedented in-flight repair operation in which spacewalking astronauts removed material protruding from the shuttle's heat shield.