When the report of the Apollo 13 mission was later published, NASA Administrator Tom Paine sent me a copy and noted under Swigert's words: "Just as you always said it would be, Arthur." I still get a very strange feeling when I contemplate this whole series of events – almost, indeed, as if I share a certain responsibility...

Another resonance is less serious, but equally striking. One of the most technically brilliant sequences in the movie was that in which astronaut Frank Poole was shown running round and round the circular track of the giant centrifuge, held in place by the "artificial gravity" produced by its spin.

Almost a decade later, the crew of the superbly successful Skylab realized that its designers had provided them with a similar geometry; a ring of storage cabinets formed a smooth, circular band around the space station's interior. Skylab, however, was not spinning, but this did not deter its ingenious occupants. They discovered that they could run around the track, just like mice in a squirrel cage, to produce a result visually indistinguishable from that shown in 2001. And they televised the whole exercise back to Earth (need I name the accompanying music?) with the comment: "Stanley Kubrick should see this." As in due course he did, because I sent him the telecine recording. (I never got it back; Stanley uses a tame Black Hole as a filing system.)

There is also the strange case of the "Eye of Japetus," described in Chapter 35, where Bowman discovers "a brilliant white oval... so sharp-edged that it almost looked... painted on the face of the little moon" with a tiny black dot at the exact center, which turns out to be the Monolith (or one of its avatars).

Well – when Voyager 1 took the first photographs of Iapetus, they did indeed disclose a large, clear-cut white oval with a tiny black dot at the center. Carl Sagan promptly sent me a print from the Jet Propulsion Laboratory with the cryptic annotation "Thinking of you..." I do not know whether to be relieved or disappointed that Voyager 2 has left the matter still open.

When, fourteen years ago, I typed the final words "For though he was master of the world, he was not quite sure what to do next. But he would think of something" I felt I had closed the circuit and precluded all possibility of a sequel. Indeed, for the next decade I ridiculed the very idea, for what seemed to me conclusive reasons. Since 2001 was concerned with the next stage of human evolution, to expect me (or even Stanley) to depict it would be as absurd as asking Moon-watcher to describe Bowman and his world.

Despite my protests, it is now obvious that my busy little subconscious was hard at work, perhaps in response to the constant stream of letters from readers wanting to know "what happened next." Finally, as an intellectual exercise, I wrote a précis of a possible sequel in the form of a short movie outline and sent copies to Stanley Kubrick and my agent, Scott Meredith. As far as Stanley was concerned, this was an act of courtesy, for I knew that he never repeats himself (just as I never write sequels), but I hoped that Scott would sell the outline to Omni magazine, which had recently published another outline, "The Songs of Distant Earth." Then, I fondly hoped, the ghost of 2001 would be finally exorcised.

Stanley expressed guarded interest, but Scott was enthusiastic – and implacable. "You've simply got to write the book," he said. With a groan, I realized that he was right...

So now, gentle reader (to coin a phrase), you can find what happens next in 2010: Space Odyssey Two. I am extremely grateful to New American Library, copyright holders of 2001: A Space Odyssey, for permission to use Chapter 37 in the new novel; It serves as a link, connecting the two books together.

A final comment on both novels as seen from a point now almost exactly midway between the year 2001 and the time when Stanley Kubrick and I started working together. Contrary to popular belief, science fiction writers very seldom attempt to predict the future; indeed, as Ray Bradbury put it so well, they more often try to prevent it. In 1964, the first heroic period of the Space Age was just opening; the United States had set the Moon as its target, and once that decision had been made, the ultimate conquest of the other planets, appeared inevitable. By 2001, it seemed quite reasonable that there would be giant space-stations in orbit round the Earth and – a little later – manned expeditions to the planets.

In an ideal world, that would have been possible: the Vietnam War would have paid for everything that Stanley Kubrick showed on the Cinerama screen. Now we realize that it will take a little longer.

2001 will not arrive by 2001. Yet – barring accidents – by that date almost everything depicted in the book and the movie will be in the advanced planning stage.

Except for communication with alien intelligences: that is something that can never be planned – only anticipated. No one knows whether it will happen tomorrow – or a thousand years hence.

But it will happen someday.

ARTHUR C. CLARKE

Colombo, Sri Lanka

November, 1982

END