I've been lucky enough to fly to space twice.

For the last several years and culminating in six months in orbit next year, I've been training for my third space flight. This one is almost in a category completely different than the previous two, specifically to live in on the space station for six months, to command a space ship and to fly a new rocket ship.

Our role is to develop techniques that allow us to provide emergency life-saving procedures to injured patients in an extreme, remote environment without the presence of a physician.

And now for Return to Flight, I'm chief of robotics working in the astronaut office in Houston, as a Canadian.

I've had a chance to fly a lot of different airplanes, but it was nothing like the shuttle ride.

And then finally, I'm the commander, so I am fundamentally responsible for the lives of the other people on board and the health and longevity of the space station. I need to bring six people back happy, healthy and feeling like they've had the best six months of their life.

I'm really looking forward to it, if you can imagine floating weightless, watching the world pour by through the big bay window of the space station playing a guitar; just a tremendous place to think about where we are in history.

It is spectacular. From about five minutes in, when we knew for sure that we were going to have the weather to go, the smile on my face just got bigger and bigger, and I was just beaming through the whole launch. I mean, it is just an amazing ride.

Our three big emergencies are fire, loss of pressurization or contaminated atmosphere. Any of those things in a spaceship are very deadly and time critical. Everybody's trained, but I'm the commander of the ship, and it's up to me to decide.

So without that Canadian invention we were grounded. And so that was a really important and key part of the mission and Canadians should take real pride in it.