Who posted the first tweet from space in 2009?

Mike Massimino posted the first tweet from space in 2009.

Massimino was serving as an astronaut on Space Shuttle Atlantis mission STS-125, which repaired the Hubble Space Telescope. During the mission, he sent a message through Twitter that became widely reported as the first tweet from space.

The post was short because the service then imposed a 140-character limit, and Massimino initially described Twitter as a way to share the mission with people on Earth. His account helped make astronaut social-media updates more familiar to the public.

People sometimes confuse this milestone with the first live video or first social-media message from orbit. Massimino’s distinction specifically concerns a tweet sent while he was in space during the 2009 Hubble servicing mission.