[to the first American astronaut to orbit the earth] Godspeed, John Glenn.

Every child has got to seek his own destiny. All I can say is that I have had a great time seeking my own.

The view of Mother Earth and the weightlessness is an addictive combination of senses.

[on thoughts he had, waiting to be picked up, after the splashdown] I sat for a long time just thinking about what I'd been through. I couldn't believe it had all happened. It had been a tremendous experience and, though I could not ever really share it with anyone, I looked forward to telling others as much about it as I could. I had made mistakes and some things had gone wrong. But I hoped that other men could learn from my experiences. I felt that the flight was a success, and I was proud of that.

[re space flight] The flight experience itself is incredible. It's addictive. It's transcendent. It is a view of the grand plan of all things that is simply unforgettable.

[re astronaut program] I volunteered for a number of reasons. One of these, quite frankly, was that I thought this was a chance for immortality. Pioneering in space was something I would willingly give my life for.

[During his visit to the Save the Chimps sanctuary] I have a great deal of respect for space travelers more senior than I, and I have a great respect for the species that did it first. (April 30, 2009)

I volunteered for this project for a lot of reasons. One of them, quite frankly, is that it is a chance for immortality. Most men never have a chance for immortality. This is something I would willingly give my life for, and I think a person is very fortunate to have something he can care that much about. [on being chosen to participate in NASA's Project Mercury in 1959]