If man survives for as long as the least successful of the dinosaurs-those creatures whom we often deride as nature's failures-then we may be certain of this: for all but a vanishingly brief instant near the dawn of history, the word 'ship' will mean- 'spaceship.'

We stand now at the turning point between two eras. Behind us is a past to which we can never return...

When the Sun shrinks to a dull red dwarf, it will not be dying. It will just be starting to live and everything that has gone before will merely be a prelude to its real history.

I don't pretend we have all the answers. But the questions are certainly worth thinking about.

Mars is the next frontier, what the Wild West was, what America was 500 years ago. It's time to strike out anew....Mars is where the action is for the next thousand years....The characteristic of human nature, and perhaps our simian branch of the family, is curiosity and exploration. When we stop doing that, we won't be humans anymore. I've seen far more in my lifetime than I ever dreamed. Many of our problems on Earth can only be solved by space technology....The next step is in space. It's inevitable.

But he knew well enough that any man in the right circumstances could be dehumanised by panic.

1. When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong. 2. The only way of discovering the limits of the possible is to venture a little way past them into the impossible. 3. Any sufficiently advanced technology is indistinguishable from magic.