UPDATE 1-NASA plans launch invitations to Twittering media

* NASA invitation-only event for new media planned

* Astronauts Twittering from orbit

* TweetUp slated for August launch (Updates number of invitations, adds bloggers)

By Irene Klotz

CAPE CANAVERAL, Fla., June 1 (Reuters) - NASA, which has tiptoed into the new world of social media with Twittering astronauts and Facebooking rovers, is taking the next step with an invitation-only outreach to "the twedia" to cover a space shuttle launch.

There are so many details to work out that the so-called TweetUp, originally planned for next week's launch of space shuttle Endeavour, has been rescheduled for the August flight of shuttle Discovery, said Michael Cabbage, a spokesman for the U.S. space agency.

NASA figures it can handle between 100 and 150 Twitterers and bloggers in a makeshift media site at the Kennedy Space Center in Florida.

Twitter is an Internet-based text message service that allows users to post updates -- called "tweets" -- of no more than 140 characters. In this instance, media members at the launch will be able to issue reports to Twitter users who have signed up to receive them. The tweets also are posted and archived on the Twitter.com website.

NASA is still deciding whom to invite, how to accommodate Twittering media's need for high-speed Internet service and whether to restrict the TweetUp to U.S. citizens, among other issues.