When people left on the Oregon Trail from St. Louis, they knew that only a fraction of them would make it to the West Coast. But they went anyway.

As soon as I could ride a bike... I was always riding over to the Museum of Science and Industry to explore. It's where I first began to develop a fascination with machines and scientific principles.

All space exploration is risky. As an astronaut, I had to decide each and every time I went to space whether or not to risk my life for the mission.

The James Webb Space Telescope was specifically designed to see the first stars and galaxies that were formed in the universe.

Science at NASA is all about exploring the endless frontier of the Earth and space.

I believe that the future of humans, and the future of Earth, depends on space exploration. That's not a French problem, or a problem for Alabama: it's a planet-wide problem. International cooperation is crucial.

When I first went to Hubble, as an astronomer and as a scientist, it was a dream come true. And as an astronaut, the Hubble missions are premiere missions because Hubble is so important to science, so important to humanity, that it's just a very special event. But as an astronomer, it was sort of the holy grail of missions.

Here we were, the only seven humans in space, repairing a telescope whose only purpose is to enrich the minds of people on planet Earth and increase our understanding of the workings of the universe. I can think of no better peaceful use of space for all humankind.

The Hubble Space Telescope is more than remarkable. It has answered just so many of those fundamental questions that people have been asking about the cosmos since people were able to ask questions.

There is no stronger case for the motivational power of real science than the discoveries that come from the Hubble Space Telescope as it unravels the mysteries of the universe.

Asteroid detection, tracking, and defense of our planet is something that NASA, its interagency partners, and the global community take very seriously.

Hubble isn't just a satellite; it's about humanity's quest for knowledge.

A day will come when other Israelis will be launched into space in the service of science and progress. For them and for us, Ilan Ramon will always be a source of inspiration as Israel's space pioneer, and his memory will be engraved in our hearts forever.

It's vital to have your own space so you aren't constantly in each other's pockets.

Man has made remarkable strides in conquering outer space, but how futile have been his efforts in conquering inner space- the space in our hearts and minds of men.

I've been approached to do some things with astronauts and the preparation that astronauts go through.

Man is an artifact designed for space travel. He is not designed to remain in his present biologic state any more than a tadpole is designed to remain a tadpole.

After one look at this planet any visitor from outer space would say 'I want to see the manager.

Resources on the planet are limited, and limited resources can come to an end. But there are also a lot of resources that are renewable. A lot of land, for example, can be reclaimed from the encroaching deserts.

The palm stands on the edge of space. The wind moves slowly in the branches. The bird's fire-fangled feathers dangle down.

“Certainly a visitor from Mars descending upon a colony of birth-injured cripples, dwarfs and hunchbacks...could not deduce what they should have been. But then let us not study cripples, but the closest thing we can get to whole, healthy men. In them, we find qualitative differences, a different system of motivation, emotion, value, thinking and perceiving. In a certain sense, only the saints are mankind. All the rest are cripples.”

A zero-gravity flight is a first step toward space travel.

"There are as many atoms in one molecule of DNA as there are stars in a typical galaxy."

"The immense distances to the stars and the galaxies mean that we see everything ins pace int he past, some as they were before the Earth came to be. Telescopes are time machines."