A Canadian astronaut, known for tweeting images of Earth from orbit has been speaking to William Shatner, from space.
Shatner tweeted Hadfield, "Are you tweeting from space?", with former astronaut Buzz Aldrin taking part in the discussion.
In the chat, Shatner said: "It's such a pleasure to talk to you. I'm so moved to be able to speak to you."
As astronaut and prolific tweeter Chris Hadfield prepares for his return to Earth, we take a look at his highlights in space.
International Space Station astronaut Chris Hadfield has recorded a video for David Bowie's Space Oddity - in space.
The Queen has sent a message to a Canadian astronaut who has become an Internet hit after he started tweeting photographs from space.