Quotes from John M. Grunsfeld

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.

At the age of six, I declared that I wanted to be an astronaut. My mother thought that was just fine, as it would encourage me to learn science, and besides, there really was no chance I would ever actually become an astronaut.

Sometimes astronauts feel a little ill or get minor scrapes. I trained as a crew medical officer to do basic treatment.

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.

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?

We don't know how many planets we're going to have to examine before we find life, and not finding it on 10 or 100 doesn't mean it's not there. This may be very tricky.

Small bodies in our solar system, like comets and asteroids, help us understand how the solar system formed and provide opportunities to advance exploration.

As a young boy growing up on the South Side of Chicago, I was inspired by the nascent space age.

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.

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 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.

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

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.

It's pretty amazing to me that we have had a space shuttle program that's lasted for 30 years - for one space shuttle. That's quite an achievement.

We're being very careful that we don't send a spacecraft to Mars with the intention of detecting Martian life - and find out that we detected the Earth life that we took with us.

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?

The things I like to do involve a lot of mental focus, a combination of physical and mental challenge. That is what mountain climbing is.

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

Going to Mars would make NASA great again.

I think it's really a sign of great American strength that we do invest the money we do in technology, in these hard projects, in NASA.

I'm absolutely compelled for NASA to send international astronauts to Mars to find out if Mars ever harbored life.

I see no difference between scientific exploration and human exploration.

Sciences are being unified by the search for life in the universe.

Hubble uniquely has been able to look in the atmosphere of a planet orbiting a nearby star and figure out what's in that atmosphere.