Tropical Storm Keith moved steadily closer toward South Florida on Tuesday with 65-mph winds and heavy rains, threatening the launch of the next space shuttle mission. Landfall was expected by Thanksgiving.

Forecasters said Keith likely would not grow into the season's sixth hurricane if it hadn't done so by Tuesday night, although its winds still would be capable of causing wide damage.The storm, born Thursday, first swept west across the Caribbean Sea, battering western Cuba and Mexico's Yucatan Peninsula with heavy rain and high winds Sunday and Monday, said Bob Sheets, director of the National Hurricane Center in Miami.

On Florida's east coast, NASA engineers at the Kennedy Space Center in Cape Canaveral prepared contingency plans for the shuttle Atlantis in case Keith approaches with high winds. The shuttle is scheduled to blast off Dec. 1 on a classified military mission.