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.

I would love to see the world's space programs continue toward sending humans to an asteroid or to Mars, with, of course, a full plan in place to bring them back. That excites me. And one of the things that excites me most about space is that we can go up there and put spacecraft in orbit with sensors that will help us measure the health of our planet, which is becoming particularly important. Our planet needs to be observed.

It is a challenge to have your launch date slip continuously.

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.

New standards for safety are now in place and Canada has helped provide tools and techniques that were needed. Technologies like these are innovative and represent great achievements for us.

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'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.