I thought that this part of Eugene Cernan's book The Last Man on the Moon was interesting. It is from page 342, the eplilogue. I always find these the most interesting, probably because it is not facts, but the opinion of the space program from someone who is very qualified to give his opinion on the subject. Anyway, here it is:
But while [the space shuttle] represented the next generation of space flight, I had already been far beyond the Earth orbits in which they would park, so I let them fly without me. I found myself with a great resume, but was chained to a desk when I really wanted to fly.
I tried to be realistic, aware that there was not a lot left out there for me to accomplish, and finally faced the facts: "I'm not going to Mars. I'm not going back to the Moon, and truth be told, I'm probably not going back into space again at all." Apollo was over and NASA's golden age of exploration was fast fading into a glimmering memory.
Truth be told, I wanted to leave Earth and visit another planet, but I would never be content just circling Earth. I wouldn't mind going to the Moon or Mars, but at this rate, I'll probably be too old by the time it happens. Stupid buerocracy.[Attempts to lure me into politics] were nice ego trips, but I wasn't interested. The kind of campaigning I prefer is speaking to a class of curious students, where I might be able to make a difference. Nothing gives me greater satisfaction than to see a kid walk away with a gleam in his or her eyes, a young face filled with the inspiration and willingness to reach for a dream because of something I might have said.
For I firmly believe that among the elementary school students today are the members to the crew of the first spaceship that will take us to Mars. This kids won't want to just go back to the Moon, where we have already been, nor will they be content to orbiting in circles around the Earth for weeks or months. We have already lived on another planet and rightfully can call the universe out home, so they will want to reach beyond that and Mars is the next giant leap for mankind.