Before he left for the International Space Station, Hadfield wrote a song with former Barenaked Ladies singer Ed Robertson.

It's called I.S.S. (Is Somebody Singing?). Of course, ISS can also stand for "International Space Station," which is fitting since the song is about what it's like to leave the Earth and go into space.

Hadfield has done some incredible things during his time on the ISS. He has made his experience in space accessible to the people on Earth. He has tweeted messages, conducted live media conferences, sent photos and kept people up-to-date on what the astronauts on the Space Station are doing.

What Hadfield is doing is unique. No astronaut has ever brought space so close to Earth before.

It's an unbelievable opportunity for people on Earth to get a better understanding of what astronauts do when they're in space.

Here's what Hadfield told CBC interviewer Jian Ghomeshi about why he's so passionate about helping earthlings to understand his space journey (the video for this interview is below):

"This is something not only personally amazing to be part of, but it is a new thing within the human experience. And it's way too good of an experience to keep to myself. It's something that I think is really important to share. Ever since my first space flight, 17 years ago, I've been trying to describe to people just how incredible it is to see our world this way, and what it means to us as a species to start leaving Earth. And now I have the time--this isn't a shuttle assembly flight--this is living in space and so I have the time to try and share it with everyone. And so I'm doing everything I can to ensure that people really get a sense of what it means and what it's like."

Source: Astronaut Chris Hadfield Debuts Song From Space