Once I finally stepped on the moon, no matter what was to come of the next three days - or the rest of my life - nobody could take those steps from me. People ask how long will they be there, and I say forever, however long forever is, like my daughter’s initials that I scribbled in the sand [TDC for Tracy Dawn Cernan].

Today, we are on a path of decay. We are seeing the book close on five decades of accomplishment as the leader in human space exploration.

Get the shuttle out of the garage. It's in its prime of its life. How could we just put it away?

Mom was always doing something for somebody. She came from a Czech background, one that made her a devout Catholic and gave her a strong belief in the family.

After Apollo 17, America stopped looking towards the next horizon. The United States had become a space-faring nation, but threw it away. We have sacrificed space exploration for space exploitation, which is interesting but scarcely visionary.

Curiosity is the essence of human existence.

Prepare for the unknown, unexpected and inconceivable . . . after 50 years of flying I'm still learning every time I fly.