Space shuttle Discovery and its crew are back on Earth.

Shuttle Discovery and its crew of seven returned to Earth on Saturday and successfully wrapped up a construction mission that left the international space station with all its solar wings and extra electrical power.

Discovery swooped through a cloudy sky and landed at NASA's spaceport in midafternoon, a little later than initially planned.

"Welcome home, Discovery, after a great mission," Mission Control radioed.

"It's good to be back home," responded Discovery's commander, Lee Archambault.

Mission Control delayed Discovery's homecoming by about 90 minutes because of windy, cloudy weather. But the wind shifted and conditions improved enough for the second and final landing opportunity of the day.

Discovery landed at its home port in Florida on Saturday afternoon, ending a 13-day mission that left the international space station with all its solar wings.

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Mission Control ordered the seven astronauts to skip their first landing opportunity and keep circling the world in hopes the conditions in Florida improve. They have one more chance for an afternoon touchdown before having to give up for the day.

The wind had picked up throughout the morning at NASA's spaceport, and the clouds appeared to be building.

"We think both those things have a good chance of looking better for our second opportunity today," Mission Control radioed.

Sunday's forecast was more dire, with a cold front expected to bring thunderstorms.

Discovery is bringing back former space station resident Sandra Magnus. Saturday marked her 134th day in orbit; she flew up in mid-November. Her replacement, a Japanese astronaut, was launched aboard Discovery on March 15.

The shuttle also is ferrying five months' worth of science samples from the space station, mostly blood, urine and saliva collected by its crew members. As many vials as possible were stuffed into the shuttle freezer, with the rest put in ice packs.

Also coming back for NASA scientists: four to five liters of recycled water that had been the astronauts' own urine and sweat. The water was produced after Discovery delivered a new urine processor that fixed the recycling machine.

NASA hopes to have the water samples tested within a month. If the toxicology results are good, the three space station residents will be given the all-clear to start drinking the recycled water up there.

The space station, meanwhile, got more guests Saturday with the arrival of a Russian Soyuz capsule, just three days after Discovery's departure.

Two of the newcomers — an American and a Russian — will swap places with commander Mike Fincke and cosmonaut Yuri Lonchakov, who have been in orbit six months.

Billionaire space tourist Charles Simonyi, a former Microsoft executive, also flew up on the Soyuz for a 1 1/2-week visit.