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. — John M. Grunsfeld Copy Share Image
I'm absolutely compelled for NASA to send international astronauts to Mars to find out if Mars ever harbored life. — John M. Grunsfeld Copy Share Image
Sciences are being unified by the search for life in the universe. — John M. Grunsfeld Copy Share Image
The most striking thing to me about human space flight and my own personal experience is that I've seen dramatic changes on Earth. We… — John M. Grunsfeld Copy Share Image
At the age of six, I declared that I wanted to be an astronaut. My mother thought that was just fine, as it would… — John M. Grunsfeld Copy Share Image
I can't imagine anywhere I'd rather be than outside the space shuttle in my space suit next to the Hubble Space Telescope. — John M. Grunsfeld Copy Share Image
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. — John M. Grunsfeld Copy Share Image
I see no difference between scientific exploration and human exploration. — John M. Grunsfeld Copy Share Image
Being an astronaut, there are not a lot of things that have really shocked me in my life. — John M. Grunsfeld Copy Share Image
I kind of feel like I found my cause in life servicing the Hubble Space Telescope. — John M. Grunsfeld Copy Share Image
