Astronauts cannot pick their nicknames and can only get their nicknames from other astronauts. Any astronaut who tries to give himself a cool nickname will regret it by getting just the opposite from his astronaut friends.

The reason we have the stars twinkle at night is because the light is being kind of blurred by the atmosphere around the Earth. That is why the Hubble Space Telescope is so good, because it is above the atmosphere. So it is kind of like looking at the sun from the bottom of a swimming pool, versus looking at the sun above the swimming pool.

I think most astronauts are not risk takers. We take calculated risks for something that we think is worthwhile.

The Earth - from our altitude at Hubble, we're 350 miles up. We can see the curvature. We can see the roundness of our home, our home planet. And it's the most magnificent thing I've ever seen. It's like looking into Heaven. It's paradise.