What you aren't ready for being the first time in space - on an emotional and intellectual level - is how looking down at Earth will profoundly affect you. Over the long term, it has changed the way I think about planet Earth. When you go around the planet and look down, you think about the fact that this is the cradle of humanity, that this is a place where seven billion people, 200 countries, live side by side, that we share this place and there's nowhere else to go.

Canada and space are a natural fit.

You're in orbit over the Earth. And suddenly it's very, very quiet. It's dramatic. You realize you're floating in the straps in your chair. And you take off your seat belt and float over to the window and look out, and you realize, "I'm not looking at a picture, here." I couldn't process it all. Even if I forget everything else in my life, that will stay with me, burned into my brain until the day I die.

Canada's a huge country, so to be able to unite the country through communication satellite technology or to be able to observe it through remote sensing technology from space is a natural fit for a country like Canada.

In 1983, NASA invited Canada to fly three payload specialists, in part because we had contributed the robotic arm that is used on the shuttle.

What you aren't ready for being the first time in space - on an emotional and intellectual level - is how looking down at Earth will profoundly affect you. Over the long term, it has changed the way I think about planet Earth. When you go around the planet and look down, you think about the fact that this is the cradle of humanity, that this is a place where seven billion people, 200 countries, live side by side, that we share this place and there's nowhere else to go.

I went to military college in Canada and graduated as an officer in the Navy but also as an engineer.