I know the stars are my home. I learned about them, needed them for survival in terms of navigation. I know where I am when I look up at the sky. I know where I am when I look up at the Moon; it's not just some abstract romantic idea, it's something very real to me. See, I've expanded my home.

Am I willing to go to Mars? Yes, but I'm not willing to spend nine months getting there, then wait 18 more months until the planets align to come home.

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].

Chemical propulsion is obsolete to go anywhere other than the moon. Three days - that's acceptable. But for Mars, we need propulsion technologies to get us there in, say, 60 days - then spend whatever length of time we want to spend and return when we want to come home.

Another hundred years may pass before we understand the true significance of Apollo. Lunar exploration was not the equivalent of an American pyramid, some idle monument to technology, but more of a Rosetta stone, a key to unlocking dreams as yet undreamed.

Here I am at the turn of the millennium and I'm still the last man to have walked on the moon, somewhat disappointing. It says more about what we have not done than about what we have done.

I'm quite disappointed that I'm still the last man on the moon.