"I have dedicated my life to answering the great scientific questions of our time and to the incredib..." — John M. Grunsfeld

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.

The Martian atmosphere is very thin. It's like our atmosphere at 100,000 feet.

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.

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