The space shuttle Discovery is now due to land on Tuesday, after bad weather forced a cancellation of Monday's landing attempt in the eastern U.S. state of Florida.
The U.S. space agency says the shuttle will have a total of six opportunities to land, either at Florida's Kennedy Space Center or at alternate sites in the western U.S. states of California and New Mexico.
NASA says the shuttle crew will fire Discovery's engines late today to adjust its orbit and position it for landing.
NASA had two opportunities to bring the shuttle home on Monday, but flight controllers told the crew that low clouds over Florida made conditions "unstable" for the crew to make a final approach to the runway.
The shuttle has enough supplies to stay in orbit safely until Wednesday.
This will be the first shuttle landing attempt since the space shuttle Columbia disintegrated re-entering the Earth's atmosphere in 2003.