Only by studying large numbers of people can we figure out, are astronauts dying at a higher rate of cancer, and what types of cancers, than other people?

I can't imagine anywhere I'd rather be than outside the space shuttle in my space suit next to the Hubble Space Telescope.

The only reason Hubble works is because we have a space shuttle.

When I grew up on the south side of Chicago, it was kind of a rough neighborhood, and when my parents saw the prospect of my older sister going to middle school, high school, they decided that we would move to the north side of Chicago, Highland Park, and for me, that was a whole new ballgame.

I kind of feel like I found my cause in life servicing the Hubble Space Telescope.

When I grew up as a kid, we didn't know there were any other planets outside of our own solar system. It was widely speculated that planet formation was an incredibly rare event and that it's possible that other planets just don't exist in our galaxy, and it's just this special situation where we happen to have planets around our sun.

The biggest honor is to be an astronaut. It's such a tremendous privilege to be able to represent humankind in our quest to explore space.

Are we alone? Many, many people on planet Earth want to know. We are on the cusp of being able to answer that question... because of the investments we're making in space technology.

The truth is, every single rocket launch off of planet Earth is risky.

Here on Earth, we're exposed to asteroids hitting the Earth, eventual changes in the Sun, changes in the Earth's climate, things we're doing to the Earth's climate. If we want to survive, we need to become a multi-planet species. That's further down the road, but the first wave is going to be the explorers.

I was not really scared on my spacewalks. We practice so much and need to stay so focused that it has a calming effect on me. I do a kind of visualization and meditation in the airlock prior to going outside, to guide my first activities once I get out in space.

All indications are that three and a half billion years ago, Mars looked like Earth. It had lakes. It had rivers. It had river deltas. It had snow-capped peaks and puffy clouds and blue sky. Three and a half billion years ago, it was a happening place. The same time on Earth, that's when life started. So did life start on Mars?

There's no question that if we stay on planet Earth and never leave, that eventually we'll be wiped out.

The team at the Space Telescope Science Institute has a demonstrated record of meeting the high-performance challenges of operating the Hubble Space Telescope and preparing for the James Webb Space Telescope.

I think that space exploration as a broad activity is the most important things that humans can do. I've always found it fascinating, interesting, compelling, and I have a drive to go out into space.

I grew up on the south side of Chicago in the 1960s, and I think there was a synchronicity of events that inspired me to be an astronaut, and, of course, the backdrop is nothing less than Mercury, Gemini, and Apollo. That was a time in our nation where we aspired to great things, and we achieved them.

I have dedicated my life to answering the great scientific questions of our time and to the incredible adventure of space exploration.

The Hubble Space Telescope, which was designed for extreme servicing, you know, we can fix everything. And the James Webb Space Telescope, where we can fix nothing. It has to work the first time. And it's a very complicated telescope.

Because of Hubble and other telescopes, we've now discovered that there are probably planets around every star, or virtually every star. There are solar systems around most stars. And the fact that we're here on a planet, Earth, means that it's likely there's lots of other Earths out there.

There's a perspective that I've gained as an astronaut that I didn't get from my science activities. In my science activities, I learned by the seat of my pants. Spending 17 years as an astronaut, I learned the NASA formalism of systems engineering as if my life depended on it. Literally.

A lot of people get home from work and sink into a good chair, the place in their life where they feel most comfortable. I get that comfort in space, the place where I most feel like I belong.

The '60s were a remarkable time because several things were happening at once. Men were leaving planet Earth, kids were breaking into the television age, and I was able to see Neil Armstrong walking on the moon.

Our journey in going beyond our home planet is a human endeavor, and in the greatest tradition of exploration, past, present, and future spacefarers will continue to be enduring catalysts for inspiration in our quest to unravel the mysteries of the universe.

The James Webb Space Telescope was specifically designed to see the first stars and galaxies that were formed in the universe. So we're gonna see the snapshot of when stars started. When galaxies started. The very first moments of the universe. And my bet? There's gonna be some big surprises.