TITUSVILLE, Fla., Sept. 10 (UPI) -- The U.S. space shuttle Discovery missed its first opportunity to re-enter Earth's atmosphere Thursday because of weather concerns, NASA said.

The space agency said that while the first pass was a "no-go," a second window of opportunity would open at 7:35 p.m. EDT. It the weather cooperates, the shuttle will then land at 8:40 p.m., about an hour and a half later than the first opportunity, NASA said.

Discovery is to land at Kennedy Space Center in Florida.

Flight controllers are closely watching the weather, which is considered very dynamic, NASA said.

Earlier in the day, Discovery's crew conducted a maneuver to avoid space debris. While uncertain, NASA said it appeared the object was from the mission's third spacewalk.