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

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.

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

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

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.

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.

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

A lot of people live in fear because they haven't figured out how you're going to react when faced with a certain set of circumstances. I've come to terms with this by looking deeply into whatever makes me fearful - what are the key elements that get the hairs up on the back of my neck - and then figuring out what I can do about it.

Almost everything worthwhile carries with it some sort of risk, whether it's starting a new business, whether it's leaving home, whether it's getting married, or whether it's flying in space.

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.

Cynicism is the easiest of all reactions, right? But it's also so disappointing and self-defeating.

Ever since I was nine years old and I watched Neil and Buzz walk on the moon, I have felt passionately that this is an interesting human adventure. This is one of the things we're doing that is really fundamentally important, as we leave our home planet, but also exciting.

Every single thing that you learn really just gives you more comfort. It's something I counsel kids all the time: if someone is willing to teach you something for free, take them up on it. Do it. Every single time. All it does is make you more likely to be able to succeed. And it's kind of a nice way to go through life.

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.

For whatever reason, I decided: 'I'm 18, I'm a man, I'm going to grow a moustache' - and it was pathetic for years - it was awful.

I don't want to be treated like I came from another planet or something or was somehow born with some weird birthright or super power. I don't view myself that way. I am a normal guy, picking up the crap from the dog and scraping the BBQ and having a beer and fixing the shed out back.

I was born in Sarnia, Ontario; a small town, it's where oil was pretty much discovered in North America.

I watched the first people walk on the moon, and to me, it was just an obvious thing - I want to somehow turn myself into that. But the real question is, how do you deal with the danger of it and the fear that comes from it? How do you deal with fear versus danger?

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.

I've been so lucky to have done two spacewalks. If you looked at your wristwatch, I was outside about 15 hours, which is about 10 times around the world. And, you know, there's a whole time dilation, distortion thing.

I've had a chance to see something that is way outside everybody else's frame of reference and gives a perspective that is very different from everyone else's.

I've put a lot of my life into making it possible to fly in space at all.

I've raised three kids: my wife and I have three kids. I've observed through direct contact the adults they are now is partially the product of where they came from and what we did. With them growing up, but partially how they were wired at birth.

If you don't like airline food, you'll probably have the same impression of space station food. I would not fly to space for the food.

In the Soyuz, the little Russian capsule, you can actually hear the banging of the big shield, the big heat shield on the bottom, as it slowly erodes away from the heat and pieces of it fly off like sparks across your window, and it's an interesting thing to ride through, you know.

In the astronaut business - the shuttle is a very complicated vehicle; it's the most complicated flying machine ever built. And in the astronaut business, we have a saying, which is, 'There is no problem so bad that you can't make it worse.'

In the late '60s, I was seven, eight, nine years old, and what was going on in the news at that time that really excited a seven, eight, nine year old boy was the Space Race.

It was remarkable to see from space how predictable people are. Our homes and towns are almost all in places with moderate temperatures, and they generally have the same shape - a thinly occupied outer blob of suburb surrounding a densely populated core, all based around a ready source of water.

It's a really big deal to do a spacewalk. It's much riskier than staying indoors. It's complex. It uses up a lot of the precious resources onboard. It uses up oxygen. It uses up carbon dioxide scrubbers.

Just taking risks for risk's sake, that doesn't do it for me. I'm willing to take risks that I think are worth it, and I've worked so hard to make sure that I survive.

My father was an airline pilot, so we travelled more spontaneously than a lot of families. On a Thursday, we could decide to go somewhere like Barbados the next day for a long weekend.

One place that I looked at a lot from space and which looks alluring is New Zealand, especially the North Island. It's a big broad valley with a river flowing through it, and you can see the wine-making dryness of the land.

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.

Russians aren't perfect. Their politics are messed up, and they keep going through self-defeating economic cycles. But I have a lot of respect for Russia, and a lot of love for Russians.

Some of the greatest reality television we ever had was the moon landings. When you think about it, that was human emotion and people, unscripted, working with each other - and millions and millions of people around the world, glued to their television sets to share real-time in a brand new, fascinating human experience.

Space is not a good place to mix foods because as soon as you take something out of the package, it becomes a flying object.

Spacewalking trumps everything. Viscerally, it is a phenomenal place to be; to be able to glance right and see the world, glance left and see the universe, and realise for a moment that you're holding on to your known existence with one hand. That's the thing.

The International Space Station is a phenomenal laboratory, an unparalleled test bed for new invention and discovery. Yet I often thought, while silently gazing out the window at Earth, that the actual legacy of humanity's attempts to step into space will be a better understanding of our current planet and how to take care of it.

The beauty of the space station, and of human spaceflight, is that it is now at a level of maturity where you can invite people on-board, which is what I worked so hard to do on social media and all the videos I made.

The best simulator for spacewalking is underwater - it allows full visuals and body movement in 3D. Virtual reality is good, too, and has some advantages, like full Station simulation, not just part. Like all simulators, they have parts that are wrong and misleading: an important thing to remember when preparing for reality.

The communities and countries best at using energy to optimize a microclimate for human life are also the ones whose people have the longest average lifespans. Canada, Sweden, and Iceland - places with inhospitable winter weather - are frontrunners in sustaining human health and life.

The world, when you look at it, it just can't be random. I mean, it's so different than the vast emptiness that is everything else, and even all the other planets we've seen, at least in our solar system, none of them even remotely resemble the precious life-giving nature of our own planet.

There are no wishy-washy astronauts. You don't get up there by being uncaring and blase. And whatever gave you the sense of tenacity and purpose to get that far in life is absolutely reaffirmed and deepened by the experience itself.

There's always constantly interesting things to do, and who knows, maybe I will be a good sculptor. I haven't decided what I am going to do next, but I am not going to quit just because I did something interesting.

To be on my very first spacewalk, to be outside, and to have contamination in my suit to the point that I couldn't see in either eye - that, I think, would cause some people to lose control.

To be one of the world's top space robotic arm operators is a necessary skill for an astronaut, but it doesn't have much carry-over.

Ultimately, leadership is not about glorious crowning acts. It's about keeping your team focused on a goal and motivated to do their best to achieve it, especially when the stakes are high and the consequences really matter. It is about laying the groundwork for others' success, and then standing back and letting them shine.

We have never lost a crew member on the space station, but of course, the Columbia accident. I was - I'd already been an astronaut for a decade when the crew of Columbia was killed. And I went through test pilot school. Rick Husband and I were out at Edwards at test pilot school together. He was the commander of Columbia.

What I like to do when I get to a new place is buy local music early on and listen to it while we're driving around. I think it helps explain and illuminate the culture of where you are if local music is playing.