It was NASA's second launch "tweetup," a meeting for NASA fans on the microblogging site Twitter. The attendants came from 30 states, including Alaska, and places as far away as England, the Netherlands, and Puerto Rico.
"This is definitely a dream come true," said Sultana Ali, of Orlando, Fla., of the chance to watch a shuttle launch in person. "I've died and gone to space nerd heaven," she tweeted later under the name @globalsultana.
Many space fans also plan to attend the science fiction Nebula Awards, which are being presented this weekend in nearby Cocoa Beach. The organizers scheduled the awards for Thursday through Sunday to coincide with the STS-132 shuttle launch.
Atlantis is slated to blast off Friday at 2:20 p.m. EDT (1820 GMT) from the seaside launch pad here. The countdown is on track and the weather is expected to cooperate. In addition to the tweeps, NASA is expecting 39,000 guests at the space center to view the launch.
"I hope I can feel the ground move and the hairs on my arm stand up," said Mauria Ellenson of Minneapolis, Minn., predicting what it might feel like at the moment of liftoff. "The experience is a once-in-a-lifetime opportunity."
More than 1,000 people applied for the roughly 150 spots available at the tweetup.
"Here at NASA, we think we have some pretty spectacular things to communicate with the public," NASA spokesman Mike Curie told SPACE.com. "In the modern era of social media we have the opportunity for direct communication. We're finding there's great interest in what NASA is doing."
The lucky attendees will be watching the launch from a spot at Kennedy Space Center near the historic countdown clock. The group arrived on Thursday and had the chance to meet astronauts and NASA officials. They also took a behind-the-scenes tour of the launch complex.
Many tweeps said they feel especially fortunate to be viewing one of the last three planned shuttle launches ever, and the final scheduled flight of Atlantis.
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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.