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It's not the first time NASA (@nasa on Twitter) has leveraged the social media messaging service. The organization technically posted the first Tweets from space this May, when user @Astro_Mike sent messages to the ground to be posted to his Twitter account by NASA staff. The addition of Jeff Williams (@Astro_jeff) and Nicole Stott (@Astro_Nicole) expanded NASA's team of tweeting astronauts.
The launch, scheduled for 2.28pm EST, is taking astronauts to the International Space Station for an 11-day mission.