Strong winds prevented space shuttle Atlantis from returning to Earth today, keeping it and its crew in orbit a 12th day.
Mission Control at Cape Canaveral, Florida, ordered the astronauts, on their way back from the international space station, to remain aloft until tomorrow afternoon.
"Just does not look like an optimum day to come home," Mission Control told commander Kenneth Cockrell. "We appreciate your patience."
The wind was blowing too hard across the Florida landing strip to allow a safe afternoon touchdown.
Nasa's cross-wind limit for a shuttle landing is 17mph and gusts were reaching as high as 24mph.
Although the cross-wind was expected to ease tomorrow, clouds could build up, according to forecasters.
Poor weather was expected at the back-up landing site in southern California.
Atlantis has enough fuel and supplies to remain in orbit until at least Tuesday and probably Wednesday.
The five astronauts are eager to come home following their successful space station construction mission.
During their voyage they delivered and installed the most expensive piece of the international space station, the Destiny laboratory.
The astronauts went out on three space walks to make the necessary laboratory connections and to equip the station with a spare radio antenna, a window shutter and other gear.
The three men living aboard space station Alpha were in charge of setting up all the equipment inside the lab module.
They will spend the next three weeks organising the laboratory and getting ready for their own trip home next month.
AP