Then there was the launch - the loudest, brightest human-engineered spectacle attendees may ever see, one that left many weeping with joy.
It should be obvious why Tweetup attendees flew or drove to Florida at their own expense, often sharing rides and houses with strangers once they got there.
For NASA, it's a different calculation. Tweetups are not expensive operations. NASA social-media manager Stephanie Schierholz wrote that the biggest cost is renting the 100-foot by 40-foot air-conditioned tent hosting attendees at the press site. But many agency staffers, Schierholz included, put in long hours outside of their day jobs.
The agency justifies Tweetups as part of its core educational mission. The publicity provided by attendees who share their experience in successive waves of web outlets - Twitter, Facebook, Flickr, Tumblr, Google+, blogs - in the days after each Tweetup can also serve as a social-media antidote to traditional-media apathy. But it's unclear how far that message carries beyond space enthusiasts.
NASA has now staged 21 Tweetups since its first in January 2009, making it one of the most frequent hosts of these gatherings. Other organizations have taken notice, from baseball teams to tech-news sites. Just last week, SpaceX, one of four companies competing to transport astronauts to the International Space Station, invited people to its facility at Cape Canaveral Air Force Station to inspect the prototype Dragon capsule it launched and recovered in December.
Between all the scheduled events and other, unofficial gatherings near Cape Canaveral, Tweetup attendees left with an eyeful and earful about space exploration. But as veterans of a launch Tweetup can report, two intense days spent with people who share the same intense interest won't just teach you about what's up there; they will also connect you to new friends down here.
Credit: Rob Pegoraro/Discovery