Quotes from John M. Grunsfeld

I don't particularly want to jump out of an airplane with a parachute if I don't have to. I don't want to go bungee jumping. I like adventure with a real purpose that I can buy into.

Growing up in Highland Park, in high school, I had some very influential teachers: I had a math teacher who taught calculus that helped me learn to be in love with mathematics; I had a chemistry teacher who inspired us to work what was in the class and to go beyond.

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

The moon's a nice place to visit, but you wouldn't want to live there.

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.

Being an astronaut, there are not a lot of things that have really shocked me in my life.

The surface of Mars is bathed in ultraviolet light, bathed in radiation. Mars's magnetic field is essentially gone, so the surface of Mars is essentially sterilized.

InSight will get to the 'core' of the nature of the interior and structure of Mars, well below the observations we've been able to make from orbit or the surface.

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.

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

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

Absolutely the most fun thing to do in space and rewarding thing, in many ways, is to look back at planet Earth.

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.

A deep ocean under the icy crust of Ganymede opens up further exciting possibilities for life beyond Earth.

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.

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

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.

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.

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.

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.

I have had the privilege to be a member of many high-performance teams at NASA, both on and off the planet.

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 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.

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.