Studying whether there's life on Mars or studying how the universe began, there's something magical about pushing back the frontiers of knowledge. That's something that is almost part of being human, and I'm certain that will continue.

It's easy to sleep floating around - it's very comfortable. But you have to be careful that you don't float into somebody or something!

The space shuttle is a better and safer rocket than it was before the Challenger accident.

On both of my flights, everything went very well.

The food isn't too bad. It's very different from the food that the astronauts ate in the very early days of the space program.

There's a huge amount of pressure on every astronaut, because when you get right down to it, the experiments that are conducted on a space flight, or the satellites that are carried up, the work that's to be done, is important and expensive work, and you are up there for a week or two on a Space Shuttle flight. The country has invested a lot of money in you and your training, and the Space Shuttle and everything that's in it, and you have to do things correctly. You can't make a mistake during that week or two that you're in space.

I suggest taking the high road and have a little sence of humour and let things roll off your back. I think that's very important.