(AP) -- On Twitter, messages of 140 characters may seem confining. Mike Massimino is finding a different type of space even more limiting - outer space.
The astronaut is sending messages to the social networking site from 350 miles above Earth on the space shuttle Atlantis - and what's cramping his "tweets" is time, not the character limit.
On Earth, Massimino tweeted about having dinner, eating lunch, working out in the gym and watching a movie. In space, he just doesn't have the time to tweet the routine, if you consider anything on orbit routine.
He averaged about four tweets a day before launch. Now that he's in orbit, it's down to one a day.
Still, Astro-Mike, which is Massimino's Twitter name, did make history.
He's the first person to tweet from space: "From orbit: Launch was awesome!! I am feeling great, working hard, & enjoying the magnificent views, the adventure of a lifetime has begun!"
Massimino's messages, promoted by NASA, are part of the space agency's full-throttle embrace of new social media. There are 36 NASA Twitter accounts, including Massimino's. NASA also has 24 Facebook accounts, 13 YouTube channels, eight Flickr photo accounts, and five MySpace sites.
Astronauts' most memorable lines have always been pithy and tweetworthy. Neil Armstrong's "That's one small step for man, one giant leap for mankind" was 57 characters - if you leave out the "a" that Armstrong later said he included before "man." And Apollo 13 astronaut James A. Lovell's "Houston we've had a problem" is only 27.
The Astro-Mike tweets come to Earth indirectly. He sends them in e-mails to Johnson Space Center in Houston and officials there post them. More than 270,000 people have signed up to follow his tweets.
On May 10 from Earth, Astro-Mike tweeted that he wouldn't be able to do much twittering from orbit because his real job is to fix the Hubble Space Telescope with his fellow astronauts in a series of five daring spacewalks. And he was right.
"The work he needs to do as a member of the Atlantis crew and a spacewalker supersedes Twitter," NASA spokesman Bill Jeffs said Thursday.
So in three days, Astro-Mike has tweeted just three times. That's as much as he tweeted in just 20 minutes on May 7 where he reported on watching a movie, being in quarantine and learning how to use his camera.
In addition to the one praising launch, Massimino tweeted from orbit about chasing down Hubble on Wednesday: "From orbit: Getting more accustomed to living in space today and getting ready for our big rendezvous with Hubble."
And on Thursday, about grabbing Hubble the previous day: "From orbit: Rendezvous and grapple were great, getting ready for our first spacewalk."
The tweets may get more scarce. The 46-year-old Massimino is spacewalking Friday and Sunday.
If his tweets leave you wanting more, NASA's official Twitter account gives almost a blow-by-blow account of spacewalks.
The commander of the next shuttle flight, Mark Polansky, is going to try to out-tweet Massimino. Not only will he use Twitter, but he is now using YouTube to solicit questions to answer from space next month.
This fits in with the social media plans of NASA, an agency that tweets more often than it launches rockets. The Mars rovers program has a Twitter account and so does the Cassini probe around Saturn. Ares, NASA's next rocket to take astronauts to the moon, has a Twitter account even though it has not been built yet.
NASA has far more Twitter accounts than any other federal agency, said acting public affairs chief Bob Jacobs. He said one reason NASA has been so big on social media is the collapse of the mainstream space and science media that used to cover the space agency.
And of course, there's the new cool tool factor that appeals to NASA's inner geek.
"As these emerging tools and technologies come online and start to be adopted, we have a responsibility to see how we can apply them," Jacobs said.
Jacobs pointed out that the official NASA Twitter on Thursday ranked 12th on the "retweet" list showing people spreading the initial tweets, something that's important to getting a message across.
But that's nothing. Astro-Mike ranks fifth.
On the Net:
Mike Massimino's Twitter page: http://www.twitter.com/Astro-mike
Mark Polansky's Twitter page: http://www.twitter.com/astro-127
NASA Twitter page: http://www.twitter.com/NASA
NASA list of social media sites: http://www.nasa.gov/collaborate/index.html
©2009 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Explore further: Study of equatorial ridge on Iapetus suggests exogenic origin