Mission specialist Mike Massimino, who has for a little more than two weeks as he trained for the mission, said during a press conference Thursday that he will Twitter from orbit when it won't interfere with the busy schedule of onboard the Atlantis. Joking that he won't be bringing his Blackberry into space, Massimino said he wasn't yet sure how the team would work out the technical issues.

"We're going to be really busy so I'm not sure how much we'll do this from orbit," he said. "I'll try to do it when I have free time in between missions. I can't make any promises but I'm going to try."

Massimino has been about the training process, along with updates about doctor's visits, press interviews and backyard barbecues. He told Computerworld last week that NASA's public relations team first suggested Twittering about his training since he'd never even tried it before. Now with 50 Tweets under his belt, he already has more than 113,000 followers.

"The whole Twitter experience has been great fun," he said today. "As astronauts, we look for ways to share the experience of what we do. The opportunity to use Twitter has been great because, by definition, it has to be short messages ... and I can fit it in."

, who will be one of the astronauts assigned to working the to grab onto and manipulate the Hubble telescope, said in a previous interview that NASA has not limited what he can Twitter about.