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.

In all of the movie portrayals, a spacewalking suit seems sort of insignificant, like a pair of shorts and a T-shirt. No one thinks much about it. But it's a spaceship, not a spacesuit, an entire life-support mechanism that's incredibly complex and cumbersome. It's very difficult to put on and off. You have to run it the whole time you are wearing it, and it redefines how you move. It's like if you put on a wetsuit and a snowmobile suit and froze yourself solid and then tried to go and do work.

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

One Chief Astronaut used to make a point of phoning the front desk at the clinic where applicants are sent for medical testing, to find out which ones treated the staff well-and which ones stood out in a bad way. The nurses and clinic staff have seen a whole lot of astronauts over the years, and they know what the wrong stuff looks like. A person with a superiority complex might unwittingly, right there in the waiting room, quash his or her chances of ever going to space.

Every decision you make, from what you eat to what you do with your time tonight, turns you into who you are tomorrow and the day after that.

There is a sunrise or a sunset from space every 92 minutes so there is an incredible amount of beauty to see from up there.

The emotional build-up and anticipation if you travel at Christmas can make it harder to enjoy a trip. I think sometimes it is better to travel outside of conventional holiday times for that reason.