It started with a message from actor William Shatner, who starred as Captain Kirk in the cult sci-fi series, asking the commander of the International Space Station, Chris Hadfield: “Are you tweeting from space?”Hadfield replied, borrowing a line from the show: “Yes, Standard Orbit, Captain. And we're detecting signs of life on the surface.”Other cast members quickly joined in the fun, including George Takei who played Sulu, and Leonard Nimoy, better known to legions of Star Trek fans as Spock.

“If you get into trouble with Nanites while you're in orbit, I know a guy who can help you contain them. He has experience,” said Wil Wheaton, one of the stars of the successor series: “Star Trek: The Next Generation.”

Wheaton was alluding to an episode in which microscopic robots escape from an experiment conducted by his character Wesley Crusher and cause havoc on the starship Enterprise.

Hadfield, again showing off his knowledge of Star Trek storylines, quipped: “Wesley, we've talked about you being on the bridge. I believe you're needed in Engineering.”

Wrapping up the online chat was a message from American astronaut Buzz Aldrin lamenting that Twitter had not existed decades ago when he and Neil Armstrong became the first humans to walk on the moon. Hadfield rocketed into space in December.

He is the first Canadian to command the International Space Station, which orbits the Earth from a distance of 350 kilometers (217 miles), circling the planet every 90 minutes at a speed of 28,000 kilometers per hour.