This story was updated at 12:47 p.m. ET.
CAPE CANAVERAL, Fla. - NASA has cleared the space shuttle Atlantis for its final planned launch on Friday afternoon as the U.S. space agency prepares to retire its aging three-shuttle fleet later this year.
Atlantis and a crew of six astronauts are poised to launch toward the International Space Station in what will be the 25-year-old shuttle's 32nd and last planned spaceflight. Liftoff is set for Friday at 2:20 p.m. EDT (1820 GMT) from NASA's Kennedy Space Center here.
"We're ready to launch Atlantis and get this mission under way," said shuttle integration manager Mike Moses in a briefing near the seaside launch site. He spoke after meeting with other mission managers at a final launch readiness review panel where the team gave Atlantis a unanimous ?go? for the Friday launch.
?Everything?s looking great,? Moses said. ?The vehicle?s doing great out on the pad.
There's a 70 percent chance of good weather for Atlantis' Friday launch, NASA officials said.
?Overall the weather looks favorable, not only for prelaunch operations today and tomorrow, but also for the launch on Friday,? said STS-132 weather officer Todd McNamara. The only concern is a small risk of a low cloud ceiling appearing over the launch site and preventing liftoff.
If NASA must delay for any reason, a similar weather forecast holds for the next two days, when the team can try again.
Atlantis' upcoming flight is the first of three final space shuttle missions ? one for each of NASA's remaining orbiters ? scheduled before the reusable space plane fleet is retired. The shuttles Discovery and Endeavour are slated to make their final flights in September and November, respectively.
"It's been a glorious career," Moses said of Atlantis' looming final spaceflight. "It's a bittersweet time, but like I said, the teams are focused on the launch here."
Atlantis is set to lift off from Launch Pad 39A on the 132nd shuttle mission of NASA's nearly 30-year shuttle program.
?It?s the type of thing where when you?re alone and thinking about it, yeah it kind of hits you,? NASA launch director Mike Leinbach said of the end of Atlantis? run. ?But when you?re on console, like me and my launch team, we have a job to do and we?re going to do that job.?
Skywatchers on Earth will have a last chance during the mission to see Atlantis from Earth as it approaches the space station, as well as after it undocks. [How to see shuttle Atlantis from Earth.]
The shuttle's all-veteran astronaut crew, commanded by U.S. Navy Capt. Ken Ham, plans to perform three spacewalks during the 12-day mission to deliver the new Russian research module, called Rassvet (which means "Dawn" in Russian), and other vital spare parts.
The six astronauts on the space station made room for the new Russian research module on Wednesday by moving a Soyuz TMA-17 spacecraft to a new parking spot, clearing an Earth-facing berth on the Russian Zarya control module for Rassvet.
So far, preparations for Atlantis' launch have gone smoothly. The countdown began Tuesday afternoon and Atlantis' astronaut crew has been at the launch site since Monday.
"The countdown is going exceedingly smoothly," Leinbach said. "Team Atlantis is really hitting its stride and is clicking on all eight cylinders...We're ready to give it our best shot Friday."
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SPACE.com is providing complete coverage of Atlantis' STS-132 mission to the International Space Station with Senior Writer Clara Moskowitz in Cape Canaveral, Fla., and Managing Editor Tariq Malik based in New York. Click here for shuttle mission updates and a link to NASA TV.