A Soyuz capsule carried an International Space Station crew of three back to Earth on Monday along with an Olympic torch that was displayed in open space as part of Russia's preparations for the Sochi 2014 Winter Games.
The forecast for Friday morning is for light winds and a zero per cent chance of weather prohibiting the loading of propellants into the external tank.
Williams is the second American woman astronaut with Indian roots, after the late Kalpana Chawla, to be selected for a space mission by NASA.
The shuttle is expected to undock from the International Space Station sometime Tuesday and land at Cape Canaveral in Florida on Thursday.
NASA engineers are focusing their attention on a gap about 4 inches by 6 inches that was discovered after Friday's launch from Kennedy Space Center.
Sunita, who arrived at the station with the STS-116 mission, replaced European Space Agency Astronaut Thomas Reiter on the Expedition 14 crew at midnight on December 12.